| This chapter describes the C library usually provided with @command{vbcc}. |
| |
| |
| @section Introduction |
| |
| To execute code compiled by @command{vbcc}, a library is needed. It |
| provides basic interfaces to the underlying operating system or |
| hardware as well as a set of often used functions. |
| |
| A big part of the library is portable across all architectures. However, |
| some functions (e.g. for input/output or memory allocation) are |
| naturally dependent on the operating system or hardware. There are |
| several sections in this chapter dealing with different versions of |
| the library. |
| |
| The library itself often is split into several parts. A startup-code |
| will do useful initializations, like setting up IO, parsing the command |
| line or initializing variables and hardware. |
| |
| The biggest part of the functions will usually be stored in one library file. |
| The name and format of this file depends on the conventions of the underlying |
| system (e.g. @file{vc.lib} or @file{libvc.a}). |
| |
| Often, floating point code (if available) is stored in a different file |
| (e.g. @file{m.lib} or @file{libm.a}). If floating point is used in an |
| application, it might be necessary to explicitly link with this library |
| (e.g. by specifying @file{-lm}). |
| |
| In many cases, the include files provide special inline-code or similar |
| optimizations. Therefore, it is recommended to always include the |
| corresponding include file when using a library function. Even if it |
| is not necessary in all cases, it may affect the quality of the generated |
| code. |
| |
| The library implements the functions specified by ISO9899:1989 as well |
| as a part of the new functions from ISO9899:1999. |
| |
| @section Legal |
| |
| Most parts of this library are public domain. However, for some systems, |
| parts may be under a different license. Please consult the system |
| specific documentation. Usually, linking against this library will |
| not put any restrictions on the created executable unless otherwise |
| mentioned. |
| |
| Parts of the math library (e.g. transcendental functions) are derived |
| from Sun's free math library: |
| @example |
| * ==================================================== |
| * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| * |
| * Developed at SunPro, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| @end example |
| |
| @node SoftfloatHauser |
| The softfloat functions, used by some targets, are derived from John |
| Hauser's IEC/IEEE Floating-point Artithmetic Package: |
| |
| @example |
| This C source file is part of the SoftFloat IEC/IEEE Floating-point |
| Arithmetic Package, Release 2. |
| |
| Written by John R. Hauser. This work was made possible in part by the |
| International Computer Science Institute, located at Suite 600, 1947 Center |
| Street, Berkeley, California 94704. Funding was partially provided by the |
| National Science Foundation under grant MIP-9311980. The original version |
| of this code was written as part of a project to build a fixed-point vector |
| processor in collaboration with the University of California at Berkeley, |
| overseen by Profs. Nelson Morgan and John Wawrzynek. More information |
| is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ |
| arithmetic/softfloat.html'. |
| |
| THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort |
| has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT |
| TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO |
| PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY |
| AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. |
| |
| Derivative works are acceptable, even for commercial purposes, so long as |
| (1) they include prominent notice that the work is derivative, and (2) they |
| include prominent notice akin to these three paragraphs for those parts of |
| this code that are retained. |
| @end example |
| |
| |
| @section Global Variables |
| |
| @subsection timezone |
| |
| On some host operating systems vclib might be unable to determine the |
| current time zone, which is required for functions like |
| @code{mktime()} or @code{localtime()} to work. Here you can overwrite |
| the following variables: |
| |
| @table @code |
| @item long __gmtoffset |
| Offset in minutes, west of Greenwich Mean Time (GMT). |
| @item int __dstflag |
| Set to non-zero, when Daylight Saving Time is active. |
| @end table |
| |
| Targets which can determine their current time zone, will do so by |
| initializing these variables on startup. |
| |
| |
| @section Embedded Systems |
| |
| This section describes specifics of the C library for embedded systems. |
| |
| @subsection Startup |
| |
| The startup is usually split into two parts. The first part is done by |
| assembly code that produces the object file @file{lib/startup.o}. This |
| assembly code is usually provided with vbcc and may have to be adapted to |
| the hardware you are using. The key actions that have to be performed by this |
| code are: |
| |
| @table @minus |
| @item hardware initialization |
| It may be necessary to perform some hardware initialization right |
| at the beginning, e.g. to configure the memory system. This has to |
| be modified by the user. |
| |
| @item variable initializations |
| When running code from ROM, some memory sections have to be |
| initialized. Usually, the init-values of initialized variables |
| have to be copied from ROM to the data segment and the values of |
| un-initialized variables have to be cleared in the bss segment. |
| This code is usually provided in the startup code. |
| |
| @item stack pointer |
| The stack pointer has to be set to a suitable memory area. |
| The startup code |
| will set the stack pointer to the value of the pointer @code{__stack}. |
| There is a default stack provided in the C library which will be used |
| unless the application defines its own stack using, for example, the |
| following code (assuming that the stack grows downwards): |
| @example |
| #define STACKSIZE <whatever> |
| |
| static long mystack[STACKSIZE/sizeof(long)]; |
| char *__stack=((char*)mystack)+STACKSIZE; |
| @end example |
| |
| @item calling @code{__main} |
| After all the above initializations have been performed, the function |
| @code{__main()} has to be called. This function is provided by the |
| library and performs high-level initializations, if necessary (mainly |
| it calls constructors created by the linker) and will then call the |
| user @code{main()} function. Note that the library |
| may not work correctly if the user @code{main()} function is called |
| directly from the startup code. |
| |
| @end table |
| |
| @subsection Heap |
| |
| When dynamic memory management is used (e.g. by using the @code{malloc()} |
| function), a heap memory area is needed to allocate memory from. The |
| @code{malloc()} function assumes that @code{__heapptr} is a variable pointing |
| to the beginning of the heap memory and that @code{__heapsize} specifies |
| the size of the heap area in bytes. The library will provide a default heap |
| memory area that can be replaced by adding, for example, the following file |
| to the application: |
| @example |
| #define HEAPSIZE <whatever> |
| |
| char __heap[HEAPSIZE],*__heapptr=__heap; |
| size_t __heapsize=HEAPSIZE; |
| @end example |
| |
| |
| @subsection Input/Output |
| |
| The standard C input/output functions are provided also for embedded systems. |
| Reading/writing to a stream will be directed to void unless the following |
| low-level I/O-functions are provided by the application: |
| @example |
| int __open(const char *name,const char *mode); |
| void __close(int h); |
| size_t __read(int h,char *p,size_t l); |
| size_t __write(int h,const char *p,size_t l); |
| off_t __seek(int h,off_t offset,int origin); |
| @end example |
| |
| The @code{__open()} function receives a name and a mode string (as in the C |
| @code{fopen()} function) as arguments and has to return a file-descriptor if |
| it is possible to open this file. The other functions are equivalent to the |
| corresponding POSIX functions. @code{__seek} can be implemented to return |
| @code{-1} if the functionality is not needed. |
| |
| Also, @code{stdin, stdout} and @code{stderr} can be used with the standard |
| descriptors. |
| |
| @subsection CTRL-C Handling |
| |
| Some targets implement handlers to terminate the program on ctrl-c or a |
| similar signal. This usually has the same effect as calling |
| @code{exit(20)}. |
| |
| If you want to change or disable the ctrl-c handling, you can overwrite |
| the function @code{void _chkabort(void)}. |
| |
| @subsection Floating Point |
| |
| Whether floating point is supported, depends on the target architecture and |
| chip. If it is supported, there will usually be a math-library that has to |
| be linked (using option @option{-lm}) when floating point is used. |
| |
| @subsection Useless Functions |
| |
| Of course, some of the C library functions can not be implemented reasonably on |
| embedded systems. These functions are contained in the library but will |
| always return an error value. Mainly affected are: |
| |
| @table @minus |
| @item locale |
| @item time |
| @item signal |
| @item filesystem functions |
| @end table |
| |
| Depending on the hardware provided by a system it is possible to implement |
| these functions and add them to the application. In this case, the new |
| functions will be used rather than the default ones returning only error |
| values. |
| |
| @subsection Linking/Locating |
| |
| To produce ROM images (e.g. in the form of absolute ELF executables, Intel |
| Hex files or Motorola S-Records), the linker is called with a linker script. |
| This script can be used to join together different sections of the input files |
| and locate them to suitable absolute memory areas. Also, this linker script |
| can be used to set symbols that may be used by the application or the startup |
| code, e.g. addresses of data sections, initialization values or small data |
| pointers. |
| |
| Code or data that has to reside at special locations can be put into a special |
| section using the @code{__section} attribute. This section can then be |
| placed at the desired location using the linker script. |
| |
| Usually, an example linker script will be provided. While this is often not |
| suitable for different chips, it may serve as a starting point. |
| |
| |
| @section AmigaOS/68k |
| |
| This section describes specifics of the C library for AmigaOS/68k |
| provided by the target @file{m68k-amigaos}. |
| The relevant files are @file{startup.o}, @file{minstart.o}, @file{minres.o}, |
| @file{vc.lib}, @file{vcs.lib}, @file{mieee.lib}, @file{mieees.lib}, |
| @file{m881.lib}, @file{m881s.lib}, @file{m040.lib}, @file{m040s.lib}, |
| @file{m060.lib}, @file{m060s.lib}, @file{msoft.lib}, @file{msofts.lib}, |
| @file{amiga.lib}, @file{amigas.lib}, @file{auto.lib} and @file{autos.lib}, |
| @file{reaction.lib}, @file{reactions.lib}. |
| |
| Note that @file{extra.lib} is no longer part of the vbcc distribution. |
| It was replaced by 'PosixLib', available on Aminet |
| @file{dev/c/vbcc_PosixLib.lha}, which has a much more comprehensive |
| support for POSIX and Unix functions. |
| |
| The following config files are available: |
| @table @code |
| @item aos68k |
| Standard startup code (@file{startup.o}) with command line parsing |
| and optional Workbench startup (@xref{Standard Startup}). |
| @item aos68km |
| Minimal startup code (@file{minstart.o}) without command line |
| parsing. You have to open all libraries yourself (@xref{Minimal Startup}). |
| @item aos68kr |
| Minimal startup code (@file{minres.o}) for resident programs. |
| Always compiles in small data mode and links with @file{vcs.lib} |
| (@xref{Minimal Resident}). |
| @end table |
| |
| @node Standard Startup |
| @subsection Startup |
| |
| The startup code currently consists of a slightly modified standard |
| Amiga startup (@file{startup.o}). The startup code sets up some |
| global variables and initializes stdin, stdout and stderr. |
| The exit code closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| |
| @node Floating point |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| At the moment there are five math libraries: |
| |
| @table @file |
| @item mieee.lib |
| This one uses the C= math libraries. The startup code |
| will always open MathIeeeSingBas.library, |
| MathIeeeDoubBas.library and MathIeeeDoubTrans.library. |
| Float return values are passed in d0, double return |
| values are passed in d0/d1. |
| A 68000 is sufficient to use this library. |
| You must not specify @option{-fpu=...} |
| when you use this library. |
| By default all floating point routines are provided via stub functions in |
| @file{mieee.lib}. With the option @option{-amiga-softfloat} you can tell |
| @command{vbccm68k} to generate inline code for calling the |
| MathIeee libraries directly. |
| |
| @item msoft.lib |
| This one is based on John Hauser's IEC/IEEE Floating-point Arithmetic |
| Package (@xref{SoftfloatHauser}) and doesn't need any system libraries for |
| FP emulation. May be slower than the ROM libraries, though. |
| Otherwise everything mentioned for @file{mieee.lib} applies here |
| as well. |
| Note that you have to call the @command{vc} frontend with the |
| @option{-rmcfg-amiga-softfloat} option, when your config file contains |
| @option{-amiga-softfloat} (which is the case for @file{aos68k} |
| since vbcc V0.9h). |
| |
| @item m881.lib |
| This one uses direct FPU instructions and function |
| return values are passed in fp0. You must have a |
| 68020 or higher and an FPU to use this library. You |
| also have to specify @option{-fpu=68881} or |
| @option{-fpu=68882}. |
| Several FPU instructions that have to be emulated on |
| 040/060 may be used. |
| |
| @item m040.lib |
| This one uses only direct FPU instructions that do not |
| have to be emulated on a 68040. Other functions use |
| the Motorola emulation routines modified by |
| Aki M Laukkanen and Matthew Hey. |
| It should be used for programs compiled for 68040 |
| with FPU. |
| Return values are passed in fp0. |
| |
| @item m060.lib |
| This one uses only direct FPU instructions that do not |
| have to be emulated on a 68060. Other functions use |
| the Motorola emulation routines modified by |
| Aki M Laukkanen and Matthew Hey. |
| It should be used for programs compiled for 68060 |
| with FPU. |
| Return values are passed in fp0. |
| @end table |
| |
| Depending on the CPU/FPU selected, including @file{math.h} will |
| cause inline-code generated for certain math functions. |
| |
| @node amiga-stack |
| @subsection Stack |
| |
| An application can specify the stack-size needed by defining a variable |
| @code{__stack} (of type @code{size_t}) with external linkage, e.g. |
| |
| @example |
| size_t __stack=65536; /* 64KB stack-size */ |
| @end example |
| |
| The startup code will check whether the stack-size specified is larger |
| than the default stack-size (as set in the shell) and switch to a new |
| stack of appropriate size, if necessary. |
| |
| If the @option{-stack-check} option is specified when compiling, the |
| library will check for a stack overflow and abort the program, if the |
| stack overflows. Note, however, that only code compiled with this |
| option will be checked. Calls to libraries which have not been compiled |
| with @option{-stack-check} or calls to OS function may cause a stack |
| overflow which is not noticed. |
| |
| Additionally, if @option{-stack-check} is used, the maximum stack-size |
| used can be read by querying the external variable @code{__stack_usage}. |
| |
| @example |
| #include <stdio.h> |
| |
| extern size_t __stack_usage; |
| |
| main() |
| @{ |
| do_program(); |
| printf("stack used: %lu\n",(unsigned long)__stack_usage); |
| @} |
| @end example |
| |
| Like above, the stack used by functions not compiled using |
| @option{-stack-check} or OS functions is ignored. |
| |
| @node amigasmalldata |
| @subsection Small data model |
| |
| When using the small data model of the 68k series CPUs, you also have |
| to link with appropriate libraries. Most libraries documented here are |
| also available as small data versions (with an 's' attached to the |
| file name). Exceptions are the math libraries. |
| |
| To compile and link a program using the small data model a command like |
| |
| @example |
| vc test.c -o test -sd -lvcs -lamigas |
| @end example |
| |
| might be used. |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on AmigaOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @end table |
| |
| @node Minimal Startup |
| @subsection Minimal Startup |
| |
| If you want to write programs that use only Amiga functions and none from |
| vc.lib you can use @file{minstart.o} instead of @file{startup.o} and |
| produce smaller executables. You can also achieve that by simply using |
| the @file{aos68km} config file instead. |
| |
| This startup code does not set up everything needed by vc.lib, so you |
| must not use most of these functions (string and ctype functions are ok, |
| but most other functions - especially I/O and memory handling - must not |
| be used). |
| @code{exit()} is supplied by minstart and can be used. |
| |
| The command line is not parsed, but passed to @code{main()} as a single |
| string, |
| so you can declare main as |
| @code{int main(char *command)} or @code{int main(void)}. |
| |
| Also no Amiga libraries are opened (but @code{SysBase} is set up), so you |
| have to define and open @code{DOSBase} yourself if you need it. |
| If you want to use floating point with the IEEE libraries |
| or @option{-amiga-softfloat} you have to |
| define and open MathIeeeSingBas.library, MathIeeeDoubBas.library and |
| MathIeeeDoubTrans.library (in this order!) and link with mieee.lib (if |
| compiled for FPU this is not needed). |
| |
| A hello world using minstart could look like this: |
| |
| @example |
| #include <proto/exec.h> |
| #include <proto/dos.h> |
| |
| struct DosLibrary *DOSBase; |
| |
| int main() |
| @{ |
| if(DOSBase=(struct DosLibrary *)OpenLibrary("dos.library",0))@{ |
| Write(Output(),"Hello, world!\n",14); |
| CloseLibrary((struct Library *)DOSBase); |
| @} |
| return 0; |
| @} |
| |
| @end example |
| |
| This can yield an executable of under 256 bytes when compiled with |
| @option{-sc -sd} and linked with @file{minstart.o} and @code{amigas.lib} |
| (using @command{vlink} - may not work with other linkers). |
| |
| @node Minimal Resident |
| @subsection Minimal Startup for resident programs |
| |
| AmigaOS can keep special "pure" programs resident in RAM, and restart them |
| from there without having to load them again from disk. To make it easy to |
| create such reentrant programs, even with static data, you can link with the |
| special startup code @file{minres.o}, which is a minimal startup code for |
| resident programs. Or simply use the config file @file{aos68kr} instead. |
| Everything mentioned for @file{minstart.o} in the previous section is also |
| valid for @file{minres.o}. |
| |
| To create real resident programs you have to follow the following rules: |
| @itemize @minus |
| |
| @item Compile all your code for the small data model (@option{-sd} option). |
| |
| @item Avoid absolute references to small data symbols. |
| Usually these are constant pointers to static data. |
| The following example creates such an illegal relocation: |
| @example |
| int x; |
| int const *p = &x; |
| @end example |
| @command{vlink} warns about all potential problems. |
| |
| @item Link with the @file{minres.o} startup code, |
| and use the small data |
| versions of linker libraries (@file{vcs.lib}, @file{amigas.lib}, etc.). |
| |
| @item Set the Pure flag in the file attributes. |
| Load the program into RAM |
| with the AmigaDOS @command{resident} command. |
| |
| @end itemize |
| |
| |
| @node amigalib |
| @subsection amiga.lib |
| |
| To write programs using AmigaOS (rather than standard C functions |
| only), a replacement for the original (copyrighted) @file{amiga.lib} |
| is provided with @command{vbcc}. This replacement is adapted to vbcc, |
| does not cause collisions with some functions (e.g. @code{sprintf}) |
| provided by the original @file{amiga.lib} and is available for the |
| small data mode as well. It is recommended to always use this library |
| rather than the original version. |
| |
| Additionally, there are header files (in the @file{proto}- and |
| @file{inline}-subdirectories) which cause inlined calls to Amiga |
| library functions. |
| |
| Besides some support functions @file{amiga.lib} contains stub routines |
| to call functions from all common AmigaOS libraries with stack arguments. |
| By including the library's proto header file you make sure that AmigaOS |
| functions are called directly by inline code, unless @code{_NO_INLINE} |
| is defined. |
| |
| Preprocessor defines to control the behaviour of vbcc's proto headers: |
| @table @code |
| @item __NOLIBBASE__ |
| Do not declare the library base symbol. |
| @item _NO_INLINE |
| Do not use optimized inline code for library function calls. |
| @end table |
| |
| Note that the OS-call inlines have been generated using the NDK3.2 clib |
| header files, while trying to keep compatibility to NDK3.9, so it is |
| advised to use one of the two NDKs for development. |
| Otherwise you will get warnings about missing @code{CONST} typedefs and |
| similar. |
| |
| Specify @option{-lamiga} to link with @file{amiga.lib}. |
| |
| @node autolib |
| @subsection auto.lib |
| |
| To link with @file{auto.lib} (or the small data version |
| @file{autos.lib}) specify |
| the @option{-lauto} or @option{-lautos} option to @command{vc}. |
| |
| When you are calling a standard Amiga library function without |
| having defined the corresponding library base, then the library base |
| as well as code to open/close it will be taken from @file{auto.lib}. |
| |
| By default, @file{auto.lib} will try to open any library version. If you |
| need at least a certain version you can define and set a variable |
| _<library-base>Ver with external linkage, e.g. (on file-scope): |
| |
| @example |
| int _IntuitionBaseVer = 39; |
| @end example |
| |
| Note that your program will abort before reaching @code{main()} if one |
| of the libraries cannot be opened. Also note that @file{auto.lib} |
| depends on constructor/destructor handling in vclib, which means it |
| cannot work when linking without vclib, without standard startup code, |
| or only with a minimal startup code, like @file{minstart.o}. |
| |
| @subsection reaction.lib |
| |
| The @file{reaction.lib} in @command{vbcc} is a port of Stephan Rupprecht's |
| rewrite of the copyrighted linker library, extended and fixed by |
| Olaf Barthel for the NDK 3.2 release. This version should work in |
| combination with NDK 3.9 as well. |
| |
| To link with @file{reaction.lib} (or the small data version |
| @file{reactions.lib}) specify the @option{-lreaction} or |
| @option{-lreactions} option to @command{vc}. |
| |
| The library contains ReAction GUI class support functions and their |
| autoinitialization code. Refer to @file{reaction_lib.doc} from your |
| NDK Autodocs for more information. As documented there, the version |
| used to automatically open the classes can be defined by the variable |
| @code{__reactionversion} with external linkage. Otherwise a default |
| of version 0 is used. |
| |
| |
| @section Kickstart1.x/68k |
| |
| This section describes specifics of the C library for Amiga Kickstart 1.2 |
| and 1.3 provided by the target @file{m68k-kick13}. |
| The relevant files are @file{startup.o}, @file{minstart.o}, @file{minres.o}, |
| @file{startup16.o}, @file{minstart16.o}, @file{minres16.o}, |
| @file{vc.lib}, @file{vcs.lib}, @file{m13.lib}, @file{m13s.lib}, |
| @file{msoft.lib}, @file{msofts.lib}, @file{m881.lib}, @file{m881s.lib}, |
| @file{amiga.lib}, @file{amigas.lib}, @file{auto.lib} and @file{autos.lib}, |
| @file{vc16.lib}, @file{vc16s.lib}, @file{m1316.lib}, @file{m1316s.lib}, |
| @file{msoft16.lib}, @file{msoft16s.lib}, @file{m88116.lib}, @file{m88116s.lib}, |
| @file{amiga16.lib}, @file{amiga16s.lib}, @file{auto16.lib} and |
| @file{auto16s.lib}. |
| |
| This target makes it possible to develop programs targeted for these older |
| versions of the Amiga operating system, using the original Commodore |
| Kickstart 1.3 header files. Note that there are also libraries and |
| config files for using a 16-bit int ABI, which was common at that time, |
| and may have some advantages on 16-bit CPUs, like the 68000 or 68010. |
| |
| The following config files are available: |
| @table @code |
| @item kick13 |
| Standard startup code (@file{startup.o}) with command line parsing |
| and optional Workbench startup (@xref{Startup13}) using 32-bit int. |
| @item kick13m |
| Minimal startup code (@file{minstart.o}) without command line |
| parsing. You have to open all libraries yourself (@xref{Minimal Startup}) |
| using 32-bit int. |
| @item kick13r |
| Minimal startup code (@file{minres.o}) for resident programs. |
| Always compiles in small data mode and links with @file{vcs.lib} |
| (@xref{Minimal Resident}) using 32-bit int. |
| @item kick13s |
| Standard startup code (@file{startup.o}) with command line parsing |
| and optional Workbench startup (@xref{Startup13}) using 16-bit int. |
| @item kick13sm |
| Minimal startup code (@file{minstart.o}) without command line |
| parsing. You have to open all libraries yourself (@xref{Minimal Startup}) |
| using 16-bit int. |
| @item kick13sr |
| Minimal startup code (@file{minres.o}) for resident programs. |
| Always compiles in small data mode and links with @file{vcs.lib} |
| (@xref{Minimal Resident}) using 16-bit int. |
| @end table |
| |
| @node Startup13 |
| @subsection Startup |
| |
| The startup code currently consists of a slightly modified standard |
| AmigaOS 1.3 startup (@file{startup.o}). The startup code sets up some |
| global variables and initializes stdin, stdout and stderr. |
| The exit code closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| At the moment there are two math libraries: |
| |
| @table @file |
| @item m13.lib |
| This one uses the C= math libraries present under Kickstart 1.2 and 1.3. |
| The startup code will always open mathffp.library, |
| MathIeeeDoubBas.library and MathIeeeDoubTrans.library. |
| Note that all single precision floating point calculations take place |
| in FFP format and have to be converted between FFP and IEEE by the |
| library. |
| Float return values are passed in d0, double return |
| values are passed in d0/d1. |
| A 68000 is sufficient to use this library. |
| You must not specify @option{-fpu=...} |
| when you use this library. |
| |
| @item msoft.lib |
| This one is based on John Hauser's IEC/IEEE Floating-point Arithmetic |
| Package (@xref{SoftfloatHauser}) and doesn't need any system libraries for |
| FP emulation. May be slower than the ROM libraries, though. |
| Otherwise everything mentioned for @file{m13.lib} applies here |
| as well. |
| |
| @item m881.lib |
| This one uses direct FPU instructions and function |
| return values are passed in fp0. You must have a |
| 68020 or higher and an FPU to use this library. You |
| also have to specify @option{-fpu=68881}. |
| Several FPU instructions that have to be emulated on |
| 040/060 may be used. |
| @end table |
| |
| @subsection Stack |
| |
| Stack-checking is available similar to AmigaOS/68k (@xref{amiga-stack}). |
| But there is no automatic stack-extension under Kickstart 1.3 and a |
| @code{__stack} variable will be ignored. |
| |
| @subsection Small data model |
| |
| Small data is supported as described for AmigaOS/68k (@xref{amigasmalldata}). |
| The startup code takes care of clearing the unititalized part of a |
| small data section (which Kickstart 1.x fails to do). |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on AmigaOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @end table |
| |
| @subsection amiga.lib |
| |
| @xref{amigalib}. |
| |
| This version of @file{amiga.lib} only supports the functionality present |
| in Kickstart 1.2/1.3. |
| |
| @subsection auto.lib |
| |
| This library corresponds to the AmigaOS/68k version (@xref{autolib}), but |
| only supports libraries of Kickstart 1.3. |
| |
| @subsection Minimal Startup |
| |
| You can use @file{minstart.o} similar to AmigaOS/68k (@xref{Minimal Startup}). |
| |
| @subsection Minimal Startup for Resident Programs |
| |
| You can use @file{minres.o} similar to AmigaOS/68k (@xref{Minimal Resident}). |
| |
| |
| @section PowerUp/PPC |
| |
| This section describes specifics of the C library for PowerUp/PPC |
| provided by the target @file{ppc-powerup}. |
| The relevant files are @file{startup.o}, @file{minstart.o}, |
| @file{libvc.a}, @file{libvcs.a}, @file{libm.a}, @file{libms.a} |
| @file{libamiga.a}, @file{libamigas.a}, |
| @file{libauto.a} and @file{libautos.a}. |
| |
| Note that @file{libextra.a} is no longer part of the vbcc distribution. |
| It was replaced by 'PosixLib', available on Aminet |
| @file{dev/c/vbcc_PosixLib.lha}, which has a much more comprehensive |
| support for POSIX and Unix functions. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up some |
| global variables and initializes stdin, stdout and stderr. |
| The exit code closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| The math library (@file{libm.a}) is linked against the floating point |
| library libmoto by Motorola. |
| |
| Depending on the CPU/FPU selected, including @file{math.h} will |
| cause inline-code generated for certain math functions. |
| |
| @subsection Stack |
| |
| Stack-handling is similar to AmigaOS/68k (@xref{amiga-stack}). |
| The only difference is that stack-swapping cannot be done. If the |
| default stack-size is less than the stack-size specified with |
| @code{__stack} the program will abort. |
| |
| @subsection Small data model |
| |
| When using the small data model of the PPC series CPUs, you also have |
| to link with appropriate libraries. Most libraries documented here are |
| also available as small data versions (with an 's' attached to the |
| file name). Exceptions are the math libraries. |
| |
| To compile and link a program using the small data model a command like |
| |
| @example |
| vc test.c -o test -sd -lvcs -lamigas |
| @end example |
| |
| might be used. |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on AmigaOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @end table |
| |
| @subsection Minimal Startup |
| |
| The provided minimal startup code (@file{minstart.o}) is used |
| similarly like the one for 68k (@xref{Minimal Startup}). Only use |
| it if you know what you are doing. |
| |
| @subsection libamiga.a |
| |
| To write programs accessing AmigaOS (rather than standard C functions |
| only), a replacement for the original (copyrighted) @file{amiga.lib} |
| is provided with @command{vbcc}. This replacement (@file{libamiga.a}) |
| automatically performs a necessary context switch to the 68k to execute |
| the system call. Furthermore, it is adapted to vbcc, |
| does not cause collisions with some functions (e.g. @code{sprintf}) |
| provided by the original @file{amiga.lib} and is available in |
| small data. |
| |
| Specify @option{-lamiga} to link with @file{libamiga.a}. |
| |
| @subsection libauto.a |
| |
| This library corresponds to the AmigaOS/68k version (@xref{autolib}). |
| |
| @section WarpOS/PPC |
| |
| This section describes specifics of the C library for WarpOS/PPC |
| provided by the target @file{ppc-warpos}. |
| The relevant files are @file{startup.o}, |
| @file{vc.lib}, @file{m.lib}, @file{amiga.lib} and @file{auto.lib}. |
| |
| Note that @file{extra.lib} is no longer part of the vbcc distribution. |
| It was replaced by 'PosixLib', available on Aminet |
| @file{dev/c/vbcc_PosixLib.lha}, which has a much more comprehensive |
| support for POSIX and Unix functions. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up some |
| global variables and initializes stdin, stdout and stderr. |
| The exit code closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| The math library (@file{m.lib}) contains functions from Sun's |
| portable floating point library. Additionally, there is a |
| @command{vbcc} version of Andreas Heumann's @file{ppcmath.lib}. |
| These routines are linked against Motorola's floating point |
| routines optimized for PowerPC and therefore are much faster. |
| |
| To make use of this library, link with @file{ppcmath.lib} before |
| @file{m.lib}, e.g. |
| |
| @example |
| vc test.c -lppcmath -lm |
| @end example |
| |
| |
| |
| Depending on the CPU/FPU selected, including @file{math.h} will |
| cause inline-code generated for certain math functions. |
| |
| @subsection Stack |
| |
| Stack-handling is similar to AmigaOS/68k (@xref{amiga-stack}). |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on AmigaOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @end table |
| |
| @subsection amiga.lib |
| |
| To write programs accessing AmigaOS (rather than standard C functions |
| only), a replacement for the original (copyrighted) @file{amiga.lib} |
| is provided with @command{vbcc}. This replacement |
| automatically performs a necessary context switch to the 68k to execute |
| the system call. Furthermore, it is adapted to vbcc, |
| does not cause collisions with some functions (e.g. @code{sprintf}) |
| provided by the original @file{amiga.lib} and is available in |
| small data. |
| |
| Specify @option{-lamiga} to link with @file{amiga.lib}. |
| |
| |
| @subsection auto.lib |
| |
| This library corresponds to the AmigaOS/68k version (@xref{autolib}). |
| |
| |
| @section MorphOS/PPC |
| |
| This section describes specifics of the C library for MorphOS/PPC |
| provided by the target @file{ppc-morphos}. |
| The relevant files are @file{startup.o}, @file{minstart.o}, |
| @file{libvc.a}, @file{libvcs.a}, @file{libm.a}, @file{libms.a} |
| @file{libamiga.a}, @file{libamigas.a}, |
| @file{libauto.a} and @file{libautos.a}. |
| |
| Note that @file{libextra.a} is no longer part of the vbcc distribution. |
| It was replaced by 'PosixLib', available on Aminet |
| @file{dev/c/vbcc_PosixLib.lha}, which has a much more comprehensive |
| support for POSIX and Unix functions. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up some |
| global variables and initializes stdin, stdout and stderr. |
| The exit code closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| The math library (@file{libm.a}) is linked against the floating point |
| library libmoto by Motorola. |
| |
| Depending on the CPU/FPU selected, including @file{math.h} will |
| cause inline-code generated for certain math functions. |
| |
| @subsection Stack |
| |
| Stack-handling is similar to AmigaOS/68k (@xref{amiga-stack}). |
| |
| @subsection Small data model |
| |
| When using the small data model of the PPC series CPUs, you also have |
| to link with appropriate libraries. Most libraries documented here are |
| also available as small data versions (with an 's' attached to the |
| file name). Exceptions are the math libraries. |
| |
| To compile and link a program using the small data model a command like |
| |
| @example |
| vc test.c -o test -sd -lvcs -lamigas |
| @end example |
| |
| might be used. |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on MorphOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @end table |
| |
| @subsection libamiga.a |
| |
| To write programs using AmigaOS compatible functions, a replacement for |
| the original (copyrighted) @file{amiga.lib} |
| is provided with @command{vbcc}. This replacement (@file{libamiga.a}) |
| will invoke the MorphOS 68k emulator to execute the system function. |
| Furthermore, it is adapted to vbcc and |
| does not cause collisions with some functions (e.g. @code{sprintf}) |
| and is available in small data. |
| |
| Specify @option{-lamiga} to link with @file{libamiga.a}. |
| |
| |
| @subsection libauto.a |
| |
| This library corresponds to the AmigaOS/68k version (@xref{autolib}). |
| |
| |
| @section AmigaOS4/PPC |
| |
| This section describes specifics of the C library for AmigaOS4/PPC |
| provided by the target @file{ppc-amigaos}. |
| The relevant files are @file{startup.o}, @file{minstart.o}, |
| @file{libvc.a}, @file{libvcs.a}, @file{libm.a}, @file{libms.a} |
| @file{libamiga.a}, @file{libamigas.a}, |
| @file{libauto.a} and @file{libautos.a}. |
| |
| Note that @file{libextra.a} is no longer part of the vbcc distribution. |
| It was replaced by 'PosixLib', available on Aminet |
| @file{dev/c/vbcc_PosixLib.lha}, which has a much more comprehensive |
| support for POSIX and Unix functions. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up some |
| global variables and initializes stdin, stdout and stderr. |
| Then it runs all constructors of dynamically linked libraries, before |
| entering the main program. |
| The exit code runs all destructors of dynamically linked libraries, |
| closes all open files and frees all memory. |
| If you link with a math library the startup/exit code will be taken |
| from there if necessary. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| The math library (@file{libm.a}) is linked against the floating point |
| library libmoto by Motorola. |
| |
| Depending on the CPU/FPU selected, including @file{math.h} will |
| cause inline-code generated for certain math functions. |
| |
| @subsection Stack |
| |
| There is no automatic stack extension for AmigaOS 4! This should be |
| done automatically by the operating system. |
| |
| @subsection Small data model |
| |
| When using the small data model of the PPC series CPUs, you also have |
| to link with appropriate libraries. Most libraries documented here are |
| also available as small data versions (with an 's' attached to the |
| file name). Exceptions are the math libraries. |
| |
| To compile and link a program using the small data model a command like |
| |
| @example |
| vc test.c -o test -sd -lvcs -lamigas |
| @end example |
| |
| might be used. |
| |
| @subsection Dynamic linking |
| Since @file{elf.library} @code{V52.2} AmigaOS4 supports dynamic linking with |
| shared object files (@file{.so} extension), similar to Unix. The default |
| behaviour is to prefer linking against a shared object over a static |
| library. To force static linking you might want to give the |
| @option{-static} option to the @file{vc} frontend. |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because on AmigaOS it is not possible to |
| obtain the time used by the calling process. |
| |
| @item Small data in dynamically linked executables |
| There is a bug in @file{elf.library} @code{V52.4} (and earlier), which |
| doesn't load @code{.sdata} and @code{.sbss} as a contiguous block into |
| memory, when the executable requires dynamic linking. I decided against |
| writing a workaround, as the bug should be fixed in OS4. |
| |
| @end table |
| |
| @subsection libamiga.a |
| |
| In contrast to other amigalibs the OS4 @file{libamiga.a} doesn't contain |
| any stubs for calling system functions. AmigaOS 4 system calls are done |
| through special macros in the SDK's interface header files. |
| |
| The library only includes some remaining amigalib functions, not already |
| integrated into the OS, like @code{CreateIO()}, but its use is discouraged. |
| |
| Specify @option{-lamiga} to link with @file{libamiga.a}. |
| |
| |
| @subsection libauto.a |
| |
| Include auto-open and -close functions for the most common OS libraries and |
| interfaces. May also be used together with newlib (see below). |
| |
| |
| @subsection newlib |
| |
| @subsubsection Introduction |
| |
| newlib.library is a shared AmigaOS4 library, which is covered by |
| several BSD like licenses, |
| and includes standard ANSI and POSIX functions as well as some |
| functions common in Unix, BSD and similar operating systems. It is |
| part of the OS4 SDK. |
| |
| The config file @file{newlib} will be created on installation to |
| use the paths for header files and libraries pointing to the |
| newlib from the SDK. |
| |
| What are the main differences between vclib and newlib? |
| |
| @itemize @minus |
| @item vclib contains (almost) only standard ANSI-C and some ISO-C99 |
| functions. If you want to port Unix programs you will probably |
| miss a lot of functions. |
| Also newlib supports things like mapping Unix directory paths to |
| Amiga paths or expanding wildcards in command lines automatically. |
| |
| @item Programs compiled for newlib will be shorter because the code for all |
| functions is not contained in the executable itself. |
| |
| @item Programs compiled for newlib will need the shared object |
| @file{libc.so} present when started. |
| |
| @item Programs compiled for newlib will probably need more memory because |
| the entire (rather large) @file{libc.so} will be loaded into memory. |
| With vclib only the functions your program uses will be in RAM. |
| However if you have several programs using newlib at the same |
| time only one copy of @file{libc.so} should be loaded. |
| @end itemize |
| |
| Things you should note: |
| |
| @itemize @minus |
| @item With newlib you do not need extra math-libraries. |
| |
| @item You must link with a vbcc-specific @file{startup.o} from the newlib |
| @file{lib/} directory as startup code. |
| The config-file @file{newlib} will usually take care of this. |
| |
| @item You _must_ use the newlib-includes from the SDK |
| rather than the ones which are for vc.lib. |
| The config-file @file{newlib} will usually take care of this. |
| |
| @item There may be vbcc-related bugs in the SDK-newlib. Patches are |
| automatically installed when using the Amiga Installer. When |
| installing the target manually, you also have to fix the SDK |
| manually. For a list of known SDK bugs at this point of time, |
| @xref{Known Newlib Bugs}. |
| @end itemize |
| |
| @node Known Newlib Bugs |
| @subsubsection Known Newlib Bugs |
| |
| @itemize @minus |
| |
| @item The @code{__asm_toupper()} and @code{__asm_tolower()} assembler inlines |
| in @file{newlib/include/ctype.h} are wrong, which makes |
| @code{toupper()} and @code{tolower()} fail when including |
| @file{ctype.h}. Fix: |
| @example |
| --- ctype.h.orig 2006-04-03 18:00:00.000000000 +0200 |
| +++ ctype.h 2017-05-07 19:32:00.000000000 +0200 |
| @@@@ -64,8 +64,8 @@@@ |
| #elif defined(__VBCC__) |
| int __asm_toupper(__reg("r3") int) = |
| "\t.extern\t__ctype_ptr\n" |
| - "\tlis\t11,(__ctype_ptr)@@ha\n" |
| - "\taddi\t11,11,(__ctype_ptr)@@l\n" |
| + "\tlis\t11,__ctype_ptr@@ha\n" |
| + "\tlwz\t11,11,__ctype_ptr@@l(11)\n" |
| "\tlbzx\t12,11,3\n" |
| "\tandi.\t12,12,2\n" |
| "\tbeq\t$+8\n" |
| @@@@ -73,8 +73,8 @@@@ |
| "#barrier"; |
| int __asm_tolower(__reg("r3") int) = |
| "\t.extern\t__ctype_ptr\n" |
| - "\tlis\t11,(__ctype_ptr)@@ha\n" |
| - "\taddi\t11,11,(__ctype_ptr)@@l\n" |
| + "\tlis\t11,__ctype_ptr@@ha\n" |
| + "\tlwz\t11,11,__ctype_ptr@@l(11)\n" |
| "\tlbzx\t12,11,3\n" |
| "\tandi.\t12,12,1\n" |
| "\tbeq\t$+8\n" |
| @end example |
| Note: This should be fixed with the latest OS4 SDK, and the V0.9h |
| installer will no longer install a patch! |
| |
| @item Newlib's @file{libauto.a} contains no working vbcc-style |
| constructors or destructors for auto-opening or -closing of libraries. |
| You can work-around it, by copying vclib's @file{libauto.a} to |
| newlib's lib-directory. Rename it, if you don't want to overwrite |
| the gcc-version of it. |
| |
| @item Some header files, like @file{sys/stat.h}, use the reserved vbcc |
| attribute @code{__mask} as an argument name. The config file should |
| take care of that, by redefining it as @code{___mask}. |
| |
| @end itemize |
| |
| @subsubsection Usage |
| |
| To compile a program to use newlib for OS4 you must make sure the proper |
| config-file (@file{newlib}) is used, e.g. |
| |
| @example |
| vc +newlib hello.c |
| @end example |
| |
| With a new SDK this will usually generate a dynamically linked executable, |
| which requires @file{libc.so}. To force a statically linked executable: |
| |
| @example |
| vc +newlib -static hello.c |
| @end example |
| |
| |
| @section Atari TOS/MiNT |
| |
| This section describes specifics of the C library for Atari TOS and MiNT. |
| M680x0 processors are supported by the target @file{m68k-atari}, while |
| ColdFire processors are supported by the target @file{cf-atari}. Both |
| share the same startup-code and are based on common library sources and |
| header files. Executables linked with this C library run on plain TOS as |
| well as on MiNT, without modifications. |
| |
| The relevant files are @file{startup.o}, @file{minstart.o}, |
| @file{libvc.a}, @file{libm.a}, @file{libgem.a}. For the M68k target |
| there are also math libs with FPU support (@file{libm881.a}, |
| @file{libm040.a} and @file{libm060.a}) and 16-bit integer versions |
| of all libraries (@file{lib*16.a}). |
| |
| The following config files are available: |
| @table @code |
| @item tos |
| M68k 32-bit @code{int} for classic TOS machines. |
| @item tos16 |
| M68k 16-bit @code{int} for classic TOS machines. |
| @item mint |
| M68k 32-bit @code{int} for MiNT. Also works on classic machines, |
| but uses an embedded a.out header for MiNT, includes a changeable |
| @code{__stksize} and sets the FastLoad, FastRAM and FastAlloc flags |
| in the header. |
| @item mintcf |
| ColdFire 32-bit @code{int}. Otherwise same as @file{mint}. |
| @end table |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up some |
| global variables and initializes stdin, stdout and stderr and returns |
| the unneeded memory to the system. |
| The exit code closes all open files and frees all memory. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point. All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| On the M68k target you have the option to enable FPU support with |
| the @option{-fpu} option and choose the appropriate math library |
| (@xref{Floating point}). Otherwise, there is a soft-float library, |
| which is compatible with all the Atari models without an FPU. |
| |
| @subsection Stack |
| |
| The default stack size is 64k. There is a MiNT tool called @file{stack} |
| which can adjust the stack size of an executable to any value, by looking |
| for a symbol named @code{__stksize} (defined by vclib's startup code). |
| |
| Additionally the required stack size can be specified by defining a |
| variable @code{__stack} (of type @code{size_t}) with external linkage, as |
| in other vbcc targets. |
| |
| @subsection 16-bit integer model |
| |
| The default libraries use 32-bit @code{int} types, but you may want to |
| use 16-bit @code{int} types for compatibility reasons. In this case you |
| have to specify the config file @code{tos16} and link with the appropriate |
| 16-bit libraries (which have a '@file{16}' attached to their name). |
| |
| To compile and link a program using 16-bit integers a command like |
| |
| @example |
| vc +tos16 test.c -o test -lm16 -lvc16 |
| @end example |
| |
| may be used. There are no 16-bit versions for ColdFire targets, |
| because this is strictly a 32-bit CPU. |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @table @code |
| |
| @item tmpfile() |
| The @code{tmpfile()} function always returns an error. |
| |
| @item clock() |
| The @code{clock()} function always returns -1. This is correct, |
| according to the C standard, because neither under TOS nor under MiNT it |
| is possible to obtain the time used by the calling process. |
| |
| @end table |
| |
| @section VideoCore/Linux |
| |
| This section describes specifics of the C library for VideoCore under Linux |
| provided by the target @file{vidcore-linux}. |
| |
| The relevant files are @code{vcload}, @file{startup.o}, |
| @file{libvc.a}, @file{libm.a}, @file{libms.a}. |
| |
| The config file @code{vc4-linux} is part of the library. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up stack and heap and provides |
| a function @code{__armcall()} to transfer control to the loader on |
| the ARM side. |
| The startup process calls constructors to set up some |
| global variables and initialize stdin, stdout and stderr if needed. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point operations that are not natively implemented. |
| All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math libraries only. |
| |
| @subsection Stack |
| |
| The library contains a default stack of 32KB. If another size is needed, |
| you can add the following to your project: |
| |
| @example |
| .align 4 |
| .space <desired-size, suitably aligned> |
| ___stackend: |
| .global ___stackend |
| @end example |
| |
| @subsection Heap |
| |
| Currently, a global variable of 16KB is used to get memory for |
| malloc() etc. If another size is needed, |
| you can add the following to your project: |
| |
| @example |
| #define HEAPSIZE <desired size> |
| |
| char __heap[HEAPSIZE],*__heapptr=__heap; |
| size_t __heapsize=HEAPSIZE; |
| @end example |
| |
| Note that this mechanism will likely be changed in the future! |
| |
| @subsection System Calls |
| |
| To access system functions from the VideoCore-side, the function |
| @code{__armcall()} can be used. It will save the current context and return |
| to the loader. Registers @code{r0-r5} (the function arguments) will be saved |
| and are available to the loader. The loader can then execute the system |
| call and resume execution, passing the return value of the system |
| function. |
| |
| Resuming is done by calling the image with offset 2. |
| |
| This functionality can also be used for debugging purposes. |
| |
| @subsection Loader |
| |
| A loader is required to execute VideoCore code from the ARM side. For |
| standalone VideoCore code, the provided loader can be used. Usually, it |
| will be necessary to adapt the loader to communicate between ARM and |
| VideoCore side during runtime. |
| |
| @subsubsection Object Format |
| |
| Currently, the loader loads an simple binary image that must be pc-relative |
| and located to address 0x00000000. Additionally, if present, a file |
| with extension @file{.reltext} will be loaded for some limited |
| relocation. This file contains a 32bit word containing the number of |
| relocations followed by n 32bit words containing an offset. For each |
| offset, the address will be relocated to the image load address. |
| |
| @subsubsection Command line arguments |
| |
| @code{vcload [-debug] [-cache] [-offset] <image-name>} |
| |
| The loader currently has the following options: |
| |
| @table @code |
| |
| @item -debug |
| |
| The loader will enter debug mode (see below). |
| |
| @item -cache |
| |
| The loader will set the LSB in the start address when executing |
| code. This is supposed to inhibit a cache flush. |
| |
| Just for testing! |
| |
| @item -offset |
| |
| The loader will allocate 1 KB more memory than required and leaves |
| this space unused at the beginning of the allocated memory. |
| |
| Just for testing! |
| |
| @end table |
| |
| @subsubsection Debug Mode |
| |
| In debug mode, the loader will wait for user input before starting the |
| VideoCore code as well as after every @code{__armcall}. |
| |
| The following commands are available: |
| |
| @table @code |
| @item w <addr> [<num>] |
| Display <num> 32bit words starting at <addr>. |
| <addr> must be the offset into the image. If <num> is omitted, |
| one unit is displayed. |
| |
| If one word is displayed, it is additionally displayed translated |
| as an offset into the image. |
| |
| @item h <addr> [<num>] |
| Display <num> 16bit halfwords starting at <addr>. |
| <addr> must be the offset into the image. If <num> is omitted, |
| one unit is displayed. |
| |
| @item b <addr> [<num>] |
| Display <num> 8bit bytes starting at <addr>. |
| <addr> must be the offset into the image. If <num> is omitted, |
| one unit is displayed. |
| |
| @item c |
| Start/continue execution. |
| |
| @item q |
| Quit. |
| |
| @item bp <addr> |
| Set a breakpoint at <addr>. |
| |
| This is currently a very crude implementation. It will just write |
| a branch to @code{__armcall()} to <addr>. If everything works well, |
| you will end in the debugger if <addr> is reached. However, the |
| arguments passed are random (and might be dangerous syscalls by |
| accident). Also, the old code at this address is currently not |
| restored. |
| |
| As a result, you must not continue execution after hitting a |
| breakpoint! |
| @end table |
| |
| |
| @subsection Restrictions |
| |
| The following list contains some restrictions of this version of the |
| library: |
| |
| @itemize @minus |
| |
| @item no real floating point support yet |
| |
| @item lots, lots, lots... |
| |
| |
| @end itemize |
| |
| @section ATARI Jaguar/68k |
| |
| This section describes specifics of the C library for ATARI Jaguar |
| provided by the target @file{m68k-jaguar}. |
| |
| The relevant files are @file{startup.o}, |
| @file{libvc.a}, @file{libm.a}, @file{libjag.a}. |
| |
| The config files @code{jaguar_unix} and @code{jaguar_windows} are part of the library. |
| |
| @subsection Startup |
| |
| The startup code @file{startup.o} sets up stack and heap. |
| The startup process calls constructors to set up some |
| global variables and initialize stdin, stdout and stderr. |
| |
| The ATARI Jaguar has no OS, so it is impossible to define how input, output and files |
| can be handled. There are a few set of function you have to define if you want to use stdio. |
| |
| Alternatively you can use the @file{libjag.a}. This library initializes a console window with stdout |
| support and uses optionally a SkunkBoard to redirect stderr and file I/O. |
| |
| @subsection Floating point |
| |
| Note that you have to link with a math library if you want to use |
| floating point operations that are not natively implemented. |
| All math functions, special startup code and |
| printf/scanf functions which support floating point are contained in |
| the math library only. Consider the ATARI Jaguar does not own a FPU so this library is pretty slow. |
| |
| @subsection Stack |
| |
| The library contains a default stack of 32KB. If another size is needed, |
| you can add a global variable named __stack to your code: |
| |
| @example |
| |
| /* Set 64kB stack */ |
| unsigned long __stack = 65536; |
| |
| @end example |
| |
| @subsection Heap |
| |
| Currently the free RAM is used as global heapsize for malloc() etc. |
| |
| It is necessary to place a symbol named _BSS_END at the end of the BSS segment. |
| The heap allocates the free RAM between _BSS_END and the bottom of the stack. |
| |
| If less size is needed feel free to manipulate the value of _BSS_END. |
| |
| All allocated heap objects can be used as internal JAGUAR objects, because they are qhrase aligned. |
| |
| @subsection stdio support |
| |
| The ATARI Jaguar lacks stdio support. So the @file{libvc.a} has just empty stub functions for |
| open, close, read and write, which you may overwrite if you need stdio. |
| Alternatively you can use @file{libjag.a} which has simple stdio |
| and file I/O functionality. |
| |
| @example |
| /** |
| * param name: name mentioned in fopen |
| * param mode: mode mentioned in fopen |
| * returns: > 0 a valid file handle |
| * < 0 to indicate an error |
| * the values 0,1,2 are used by stdin, stdout and stderr |
| * |
| * No need to handle stdin, stdout and stderr here |
| */ |
| int jagopen(const char *name,const char *mode) |
| |
| /** |
| * param handle: handle from jagopen |
| * |
| * No need to handle stdin, stdout and stderr here |
| */ |
| void jagclose(int handle) |
| |
| /** |
| * param handle: handle from jagopen |
| * param p: points to the char buffer to fill. |
| * param l: buffer size of p |
| * returns: >=0 number of read bytes |
| <0 indicate an error |
| * |
| * Handle stdin, stdout and stderr here |
| */ |
| size_t jagread(int handle,char *p,size_t l) |
| |
| /** |
| * param handle: handle from jagopen |
| * param p: points to the char buffer to write. |
| * param l: number of bytes of p |
| * returns: >=0 number of bytes written |
| <0 indicate an error |
| * |
| * Handle stdin, stdout and stderr here |
| */ |
| size_t jagwrite(int handle,const char *p, size_t l) |
| |
| /** |
| * param handle: handle from jagopen |
| * param offset: number of bytes to seek. |
| * param direction: see fseek direction |
| * returns: =0 successful seek |
| <>0 indicate an error |
| -1: seek not supported |
| * |
| * Handle stdin, stdout and stderr here |
| */ |
| long jagseek(int handle,long offset,int direction) |
| @end example |
| |
| @subsection The jaglib |
| |
| The jaglib @file{libjag.a} provides simple functions to support your first |
| steps in ATARI Jaguar programming. It initializes a simple console output window and comes with |
| an old ATARI character set. |
| If a SkunkBoard is available I/O functionality can be redirected. |
| |
| Your first Jaguar program can look like this: |
| |
| @example |
| |
| #include <stdio.h> |
| |
| int main() |
| @{ |
| printf("Hello, world\n"); |
| @} |
| |
| @end example |
| |
| Keep in mind: Your JAGUAR will get a red background color to indicate @code{main()} has exited. |
| |
| The jaglib API documentation is available in a separate document. There is more demo code |
| available in the @uref{https://github.com/toarnold/jaglib-demo, jaglib-demo} gibhub repository. |
| |
| @section 6502/C64 |
| |
| This is a port of vclib to the C64. |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x801. A BASIC line is included so that the program can be started using @code{RUN} |
| from BASIC. The startup code |
| will turn off the BASIC ROM to allow usage of RAM until 0xD000 and most of the |
| zero page without need for any special handling. The BSS segment will be cleared |
| during startup. |
| |
| With the default configuration, after exiting the C program, an infinite loop will |
| be entered. When using the @code{+c64r} config, the program will return to BASIC |
| an can be started again. |
| However, this needs additional memory as the init values for the data section have |
| to be stored in RAM. Also, some register values and zero page contents have to be |
| saved. The overhead depends on the amount of initialized variables. |
| |
| @subsubsection Command line |
| |
| Command line parameters are supported by using the convention/code submitted by |
| Stefan Haubenthal. |
| |
| Command-lines look like these lines: |
| |
| @example |
| run |
| run : rem |
| run:rem arg1 " arg 2 is quoted " arg3 "" arg5 |
| @end example |
| |
| |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x02..0x8d} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the user stack is mapped from @code{0xC800..0xD000}. The size can be |
| changed at the top of @code{vlink.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting after the BASIC init line. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsubsection Banking |
| |
| The following banking models are supported: |
| |
| @table @code |
| @item -reuflat |
| This library supports a REU using a flat 16MB address space. The memory has to |
| be addressed through far-pointers. It is not possible to declare variables in |
| the REU nor to place code in the REU. The memory is addressed as 0x000000 to |
| 0xFFFFFF. All accesses through far-pointers are addressing the REU. It is not |
| possible to address the C64 memory through a far-pointer. |
| |
| Far-pointer arithmetic only works on the lower 16bits. It is not possible to |
| cross a bank boundary using far-pointers. Huge-pointers will support this, but |
| are not yet fully implemented. In the meantime it is possible to use long integers |
| and cast them to far-pointers. |
| |
| Use @code{-lreuflat} to link with this library. Note that the library does |
| not check for the presence of a REU. |
| |
| @item -reubank |
| This configuration reserves a 16KB memory space within the C64 memory as window |
| for banking. As the bank number is stored as a single byte (with bank |
| 255 denoting the unbanked memory), it is only possible to address up to |
| about 4MB of memory in the REU. |
| |
| Variables and code can be mapped into the REU using the @code{__bank()} attribute |
| or @code{#pragma bank}. When calling a banked function, the corresponding bank |
| will be copied from the REU into the C64 memory window. |
| |
| Use the @code{+c64reu} configuration to use this mechanism. Currently the |
| linker file provides 8 banks resulting in a 128K REU image. More banks can |
| be added for larger expansions. |
| |
| The configuration will create a usually C64 prg file containing the unbanked |
| code and data as well as a REU image with extension @code{.b0}. It must |
| be loaded (e.g. with an emulator or the TurboChameleon) before the prg file |
| can is executed. |
| @end table |
| |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| stdio supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (keyboard). Both are unbuffered by default. |
| |
| Furthermore, file IO with standard C functions is supported |
| for 1541 and compatible disk drives. Other devices have not been tested. |
| Only sequential reading and writing of files is supported. No seeking etc. |
| There are hardcoded limits for the maximum number of open files and the |
| maximum length of filenames. |
| |
| The @code{remove()} and @code{rename()} functions are supported using 1541 |
| |
| By default, device ID 8 is used. Another device ID can be specified as prefix |
| to the filename: |
| |
| @example |
| /* try to open file "test" on the second drive */ |
| FILE *f; |
| f=fopen("9:test","r"); |
| ... |
| @end example |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |
| |
| @section 6502/NES |
| |
| This is a port of vclib to the NES console. |
| |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is dependent on the ROM used. Currently two example configurations |
| are provided. They can be selected with @code{+nrom256v} and @code{+unrom512v}. Have a |
| look at the corresponding linker scripts in @code{vbcc/targets/6502-nes} for further |
| details. |
| |
| The necessary library routines to support configurations with several ROM banks are |
| included. |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. The entire zero page can be used, but this can be changed |
| in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the user stack starts from @code{0x0800} growing downwards. |
| |
| @subsubsection Heap |
| |
| By default, code and data/BSS are mapped starting after the system stack at @code{0x0200}. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| At the moment, stdio only supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (simple input via joypad). |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| For input, up/down changes the current character, left/right moves the cursor, |
| the B button deletes from the cursor position, and the A button confirms the input. |
| You do not want to use this in real code. |
| |
| The library contains a default character set. To replace it, link an object that |
| contains a character set mapped to section @code{chars} and defines the global symbol |
| @code{___stdchr}. |
| |
| To replace stdio, the function @code{__read()} and @code{__write()} have to be |
| implemented. |
| |
| @subsection Interrupts |
| |
| The library contains a default NMI implementation that is used for stdio handling |
| and the @code{clock()}-function. It can be replaced by linking with an own |
| implementation that starts at the global symbol @code{___nmi}. In this case the stdio and |
| timing functions from vclib can not be used. |
| |
| @code{___irq} can be used to overwrite the other IRQ vector. The default implementation |
| in the library immediately returns. |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| IEEE floating point is currently not available for this target. |
| |
| |
| @section 6502/Atari |
| |
| This is a port of vclib to Atari 8bit computers. |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x600. The memory area can be adapted by changing @code{MEMSTART} and |
| @code{MEMEND} in @code{vlink.cmd}. |
| |
| With the default configuration, after exiting the C program, it will wait |
| for pressing the return key before returning to DOS. |
| |
| @subsubsection Command line |
| |
| Command line parameters are not yet supported. |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x82..0xFF} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the startup code maps the user stack from |
| @code{MEMTOP-STACKLEN..MEMTOP}. |
| The size can be changed at the top of @code{vlink.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting at @code{MEMSTART}. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsubsection Banking |
| |
| Banking support for this target has not yet been implemented. |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| At the moment, stdio only supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (keyboard). Both are line-buffered by default. |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |
| |
| @section 6502/BBC Micro/Master |
| |
| This is a port of vclib to BBC 8bit computers. |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x1900 up to 0x7B00 with 256 bytes of software stack. The memory area can be adapted by |
| changing @code{OSHWM}, @code{HIMEM} and @code{STACKSTART} in @code{vlink.cmd}. |
| |
| With the default configuration (@code{+bbc}), after exiting the C program, the code will |
| enter an endless loop. If the reentrant configs are used (@code{+bbcr} or |
| @code{+bbcbr}), the program will return to the command prompt. As this |
| requires saving the zero page, a bit more memory is used. |
| |
| |
| @subsubsection Command line |
| |
| If @code{main()} uses arguments, the command line parameters will be passed |
| accordingly. There are hardcoded limits to the number of arguments (currently 8) |
| and the maximum total command length (currently 80). |
| |
| Space is used to separate arguments. The quote character (@code{"}) can be used |
| to group arguments containing spaces. |
| |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x00..0x90} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the startup code maps the user stack from |
| @code{STACKSTART..HIMEM}. |
| The size can be changed at the top of @code{vlink.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting at @code{OSHWM}. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsubsection Banking |
| |
| When using the @code{+bbcb} or @code{bbcbr} configurations, vbcc supports |
| banked memory, including automated bank-switching. Up to 16 sections of 16K |
| size are supported. Each section starts at 0x8000. |
| |
| The corresponding linker |
| files @code{vlinkb.cmd} and @code{vlinkbr.cmd} can be edited to choose the |
| banks that are required. Unused banks can be removed by commenting out |
| (using old-style C-comments) the corresponding entries in the @code{SECTIONS} |
| part of the linker file. When using bank 1-3 the section in the linker file |
| could look like this: |
| |
| @example |
| ... |
| |
| SECTIONS |
| @{ |
| text : @{*(text)@} >ram |
| .dtors : @{ *(.dtors) @} > ram |
| .ctors : @{ *(.ctors) @} > ram |
| rodata : @{*(rodata)@} >ram |
| data: @{*(data)@} >ram |
| init : @{*(init)@} >ram |
| zpage (NOLOAD) : @{*(zpage) *(zp1) *(zp2)@} >zero |
| bss (NOLOAD): @{*(bss)@} >ram |
| |
| /* |
| b0 : @{.=PAGEADDR; *(text0) *(rodata0) *(data0) *(bss0) |
| RESERVE(PAGEADDR+PAGESIZE-.); |
| @} >b0 AT>dummy0 |
| */ |
| |
| b1 : @{.=PAGEADDR; *(text1) *(rodata1) *(data1) *(bss1) |
| RESERVE(PAGEADDR+PAGESIZE-.); |
| @} >b1 AT>dummy1 |
| |
| b2 : @{.=PAGEADDR; *(text2) *(rodata2) *(data2) *(bss2) |
| RESERVE(PAGEADDR+PAGESIZE-.); |
| @} >b2 AT>dummy2 |
| |
| b3 : @{.=PAGEADDR; *(text3) *(rodata3) *(data3) *(bss3) |
| RESERVE(PAGEADDR+PAGESIZE-.); |
| @} >b3 AT>dummy3 |
| /* |
| b4 : @{.=PAGEADDR; *(text4) *(rodata4) *(data4) *(bss4) |
| RESERVE(PAGEADDR+PAGESIZE-.); |
| @} >b4 AT>dummy4 |
| */ |
| |
| ... |
| |
| @end example |
| |
| During the linking process, apart from the normal output file, a 16K large |
| image for each bank and a loader script will be generated. E.g. when using banks |
| 1-3 and using the output file name test, the following files will be generated: |
| |
| @table @code |
| @item @code{test} |
| The unbanked code/data. |
| |
| @item @code{test.inf} |
| Info file with start address. |
| |
| @item @code{testb1} |
| Image for bank1. |
| |
| @item @code{testb2} |
| Image for bank2. |
| |
| @item @code{testb2} |
| Image for bank2. |
| |
| @item @code{loadtest} |
| Loader |
| |
| @end table |
| |
| The contents of the loader @code{loadtest} will look like this: |
| |
| @example |
| *srload testb1 8000 1 |
| *srload testb2 8000 2 |
| *srload testb3 8000 3 |
| *run test |
| @end example |
| |
| The program can be started with @code{*exec loadtest}. |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| @code{stdout}, @code{stderr} (both using the screen) and @code{stdin} (keyboard) |
| are supported. Furthermore normal file operations are possible using the |
| usual C functions. There are hardcoded limits on the maximum number of |
| simultaneously open files as well as the length of filenames. |
| |
| Sequential reading and writing is supported, but no seeking. Furthermore, the |
| @code{remove()} call is supported. |
| |
| When using stdio to emit VDU control sequences, the function |
| @code{__vdu_sequence()} is available to ensure verbatim 1:1 transmission |
| of all characters: |
| |
| @example |
| /* print diagonal line */ |
| __vdu_sequence(1); |
| for(int i=0;i<20;i++) |
| printf("\x1f%c%cO",i,i); |
| __vdu_sequence(0); |
| @end example |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |
| |
| |
| |
| @section 6502/MEGA65 |
| |
| This is a port of vclib to the MEGA65. This port is intended for the C65 mode |
| with a C65 or compatible ROM (although the ROM is not used after the |
| program is started). The C64 configuration can be used to create programs for |
| the C64 mode. |
| |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| The following basic configurations are available. See below for more details: |
| |
| @table @code |
| @item +m65s |
| Standard unbanked configuration. |
| |
| @item +m65sr |
| Standard unbanked reentrant configuration. |
| |
| @item +m65sb |
| Standard banked configuration. |
| |
| @item +m65l |
| Large unbanked configuration. |
| |
| @item +m65lr |
| Large unbanked reentrant configuration. |
| |
| @item +m65lb |
| Large banked configuration. |
| |
| @end table |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x2001. A BASIC line is included so that the program can be started using @code{RUN} |
| from BASIC. The startup code |
| will switch to VIC-IV mode, remove write protection of ROM banks, turn on full |
| speed and change to a suitable mapping. |
| The BSS segment will be cleared during startup. |
| |
| There are two sets of configurations that affect the configuration of |
| upper memory. The standard versions (@code{+m65s, +m65sr, +m65sb}) |
| will keep the IO area mapped in at $D000. |
| This will limit the contiguous memory block for unbanked configurations to 0xCFFF. |
| For banked configurations (see below) it will make a 16K window from |
| 0x8000..0xBFFF available for banking. The large configurations |
| (@code{+m65l, +m65lr, +m65lb}) will move the upper bound for unbanked programs |
| to 0xFFFF. With banking, 32K window will be available from 0x8000..0xFFFF. |
| In both cases the total amount of memory available for banking is the same in |
| both configurations. |
| |
| While the large configurations provide larger contiguous memory areas, accesses |
| to the IO area have to be made through extended 28bit instructions which are |
| much larger and slower. For programs doing many IO accesses, the standard |
| configurations are recommended. |
| |
| With the default configurations, after exiting the C program, an infinite loop will |
| be entered. When using the reentrant (@code{+m65sr, +m65lr}) configs, the |
| program will return to BASIC an can be started again. |
| However, this needs additional memory as the init values for the data section have |
| to be stored in RAM. Also, some register values and zero page contents have to be |
| saved. The overhead depends on the amount of initialized variables. |
| |
| Caution: The current configuration assumes that the Z register always contains 0. |
| To work correctly, the Z register has to be 0 when C code is |
| executed. The startup code will set it correctly and the compiler generated code will |
| not touch it. However, when calling other code you may have to take care |
| to save/restore the Z register or to set the Z register to 0 again. |
| |
| @subsubsection Command line |
| |
| Command line parameters are supported by using the convention/code submitted by |
| Stefan Haubenthal. |
| |
| Command-lines look like these lines: |
| |
| @example |
| run |
| run : rem |
| run:rem arg1 " arg 2 is quoted " arg3 "" arg5 |
| @end example |
| |
| |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x02..0xFF} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the user stack is mapped from @code{0xB800..0xC000}. For the banked version, |
| it is mapped from @code{0x7800..0x8000}. The size can be |
| changed at the top of @code{vlink.cmd} and @code{vlinkbank.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting after the BASIC init line. |
| The heap is placed in the remaining space depending on the configuration. |
| |
| @subsubsection Banking |
| |
| The following banking models are supported: |
| |
| @table @code |
| @item +m65sb |
| 16K window at 0x8000 with IO area mapped in at all times. |
| |
| @item +m65lb |
| 32K window at 0x8000. |
| @end table |
| |
| |
| Automated bank switching is supported in both modes. The mapping of banks to |
| real memory in the standard configuration is like this: |
| @example |
| Unbanked: 0x000000..0x007FFF |
| Bank0: 0x008000..0x00BFFF |
| Bank1: 0x00C000..0x00FFFF |
| Bank2: 0x010000..0x013FFF |
| Bank3: 0x014000..0x017FFF |
| ... |
| @end example |
| |
| On the large configuration, it looks like this: |
| @example |
| Unbanked: 0x000000..0x007FFF |
| Bank0: 0x008000..0x00FFFF |
| Bank1: 0x010000..0x017FFF |
| Bank2: 0x018000..0x01FFFF |
| Bank3: 0x020000..0x027FFF |
| ... |
| @end example |
| |
| In both cases, the program start is moved to 0x1000. |
| When using the banked configurations, the code can not be simply loaded from |
| BASIC. The linker will create on large image without any BASIC lines. The |
| file can be executed from SD-card by using a special loader that can be loaded |
| from BASIC off a disk or disk image. When specifying a name as command line |
| argument (see above), the loader will try to load this image from SD-card. If |
| no argument is given, the loader will look for a file of the same name. |
| Therefore by renaming the loader it can be made to automatically run a |
| specific file. |
| |
| If the loader is on the current disk/image and @code{myimage} on the SD: |
| @example |
| LOAD "LOADER" |
| RUN:REM MYIMAGE |
| @end example |
| |
| After renaming @code{LOADER} to @code{MYIMAGE}, it can be done like this: |
| @example |
| RUN "MYIMAGE" |
| @end example |
| |
| The colour RAM will be relocated to 0xFF80800 before loading to avoid being |
| overwritten through the window at 0x1F800. |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| At the moment, stdio only supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (keyboard). Both are unbuffered by default. |
| Using those streams will directly access the screen buffer and keyboard |
| hardware. No ROM functions are needed once the program runs. |
| |
| Furthermore it is possible to read files on the SD-card using standard |
| C functions after opening them using @code{fopen()}. Hyppo services are |
| used to read those files. There are several limitations due to the |
| restrictions of Hyppo: |
| |
| @itemize |
| @item Files can only be read sequentially, no seeking etc. |
| @item Files can not be written to. |
| @item Only one file can be open at the same time. |
| @end itemize |
| |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| @subsection Multiplication/Division |
| |
| When generating code for the MEGA65, @code{vbcc} will make use of hardware |
| multiplier/divider. This can greatly improve performance of such operations. |
| Please note the following issues: |
| |
| @itemize |
| @item Some versions of the MEGA65 core contain a bug in the hardware divider |
| which will calculate wrong results in certain cases. As workaround you can |
| specify option @code{-div-bug} to use (much slower) 6502 software |
| routines instead. Multiplication is not affected by the bug and will still |
| be using the hardware multiplier. |
| |
| @item The hardware multiplier registers are mapped in the IO area. When using |
| the large configurations (@code{+m65l, +m65lr, +m65lb}), they can only |
| be accessed using extended 28bit instructions. The code generator and |
| library functions will handle this, but there is some overhead (still |
| nowhere near using software multiplication). If your code is speed |
| critical and uses many multiplications we strongly recomment to use |
| the standard configurations (@code{+m65s, +m65sr, +m65sb}). Those will |
| set the option @code{-m65io} that tells @code{vbcc} to use faster |
| direct IO accesses. |
| @end itemize |
| |
| @subsection Interrupts |
| |
| The provided configurations will disable interrupts on the MEGA65. All the |
| library functions are written to work with disabled interrupts and do not use |
| any ROM routines. The interrupt handlers in existing C65 ROMs do not work well |
| with assembly language code and deficiencies in the mapping hardware make it |
| very hard to use the ROM in a non-BASIC environment. |
| |
| If an application wants to use interrupts, interrupt vectors have to be |
| installed at 0xFFFA..0xFFFF. Take care that there are always valid vectors |
| visible at this address (especially in a banked configuration). Also take |
| care that those always point to a valid handler that is visible (i.e. do |
| not use an ISR in banked memory). |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |
| |
| @section 6502/X16 |
| |
| This is a port of vclib to the Commander X16. |
| |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x801. A BASIC line is included so that the program can be started using @code{RUN} |
| from BASIC. The startup code |
| will turn off the BASIC ROM to allow usage of RAM until 0x9F00 and most of the |
| zero page without need for any special handling. The BSS segment will be cleared |
| during startup. |
| |
| With the default configuration, after exiting the C program, an infinite loop will |
| be entered. When using the @code{+x16r} config, the program will return to BASIC |
| an can be started again. |
| However, this needs additional memory as the init values for the data section have |
| to be stored in RAM. Also, some register values and zero page contents have to be |
| saved. The overhead depends on the amount of initialized variables. |
| |
| @subsubsection Command line |
| |
| Command line parameters are supported by using the convention/code submitted by |
| Stefan Haubenthal. |
| |
| Command-lines look like these lines: |
| |
| @example |
| run |
| run : rem |
| run:rem arg1 " arg 2 is quoted " arg3 "" arg5 |
| @end example |
| |
| |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x02..0x7e} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the user stack is mapped from @code{0x9700..0x9F00}. The size can be |
| changed at the top of @code{vlink.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting after the BASIC init line. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsubsection Banking |
| |
| Banking support for this target is not yet implemented. |
| |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| At the moment, stdio only supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (keyboard). Both are unbuffered by default. |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |
| |
| @section 6502/PET |
| |
| This is a port of vclib to the CBM PET series of computers. |
| |
| @subsection Startup and Memory |
| |
| Startup and memory layout is described in the following paragraphs. |
| |
| @subsubsection Startup |
| |
| The default linker file creates program files that are loaded to address |
| 0x401. A BASIC line is included so that the program can be started using @code{RUN} |
| from BASIC. RAM is available until 0x7FFF and most of the |
| zero page without need for any special handling. The BSS segment will be cleared |
| during startup. |
| |
| With the default configuration, after exiting the C program, an infinite loop will |
| be entered. When using the @code{+petr} config, the program will return to BASIC |
| an can be started again. |
| However, this needs additional memory as the init values for the data section have |
| to be stored in RAM. Also, some register values and zero page contents have to be |
| saved. The overhead depends on the amount of initialized variables. |
| |
| @subsubsection Command line |
| |
| Command line parameters are supported by using the convention/code submitted by |
| Stefan Haubenthal. |
| |
| Command-lines look like these lines: |
| |
| @example |
| run |
| run : rem |
| run:rem arg1 " arg 2 is quoted " arg3 "" arg5 |
| @end example |
| |
| |
| |
| @subsubsection Zero Page |
| |
| @code{vbcc} uses a number of zero page locations for register variables, stack |
| pointer etc. in section @code{zpage}. Also, variables can be mapped to zero page using |
| the @code{__zpage} attribute. By default the area @code{0x02..0x8d} |
| is used, but this can be changed in the linker file. |
| |
| @subsubsection Stack |
| |
| By default, the user stack is mapped from @code{0x7F00..0x7FFF}. The size can be |
| changed at the top of @code{vlink.cmd}. |
| |
| @subsubsection Heap |
| |
| Code and data/BSS are mapped starting after the BASIC init line. |
| The heap is placed in the remaining space to stack start. |
| |
| @subsubsection Banking |
| |
| Automated banking is currently not supported. |
| |
| |
| @subsection Runtime |
| |
| Apart from standard C library functions, @code{libvc.a} also provides a few |
| runtime support functions needed by the compiler. Apart from the math and |
| floating point functions mentioned in the documentation of the 6502 backend, |
| it includes functions for saving/restoring registers. |
| |
| @subsection @code{stdio} |
| |
| At the moment, stdio only supports @code{stdout}, @code{stderr} (both using the |
| screen) and @code{stdin} (keyboard). Both are unbuffered by default. |
| |
| @code{printf/scanf} functions which support floating point are contained in |
| the math library only. |
| |
| |
| @subsection Floating Point / wozfp |
| |
| When using floating point, the math library @code{libm.a} must be linked using |
| the @code{-lm} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on Steve Wozniaks routines from the 70s, |
| somewhat adapted to the ABI of @code{vbcc}. These functions are small and |
| reasonably usable, but they do not fully satisfy the requirements of C99. |
| |
| Only a part of the C library functions for floating point is implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp()} |
| @item @code{pow()} |
| @item @code{log()} |
| @item @code{log10()} |
| @end itemize |
| |
| @subsection Floating Point / IEEE |
| |
| When using IEEE floating point, @code{-ieee} must be specified and the math library |
| @code{libmieee.a} must be linked using |
| the @code{-lmieee} option. It contains the floating routines as well as versions of |
| the @code{printf/scanf} family that support floating point. |
| |
| The floating point routines are based on SANE, |
| somewhat adapted to the ABI of @code{vbcc} using wrapper functions. |
| These functions should be fully C and IEEE compliant and provide precise results for |
| 32 and 64bit floating point numbers (the library actually internally calculates |
| all operation using 80bits, but vbcc currently only uses up to 64 bits). |
| |
| Currently, this library probably must be run from RAM. |
| |
| Most parts of the C library functions for floating point are implemented. The |
| list currently includes: |
| |
| @itemize |
| @item @code{exp(), expf(), expl()} |
| @item @code{exp2(), exp2f(), exp2l()} |
| @item @code{exp1m(), exp1mf(), exp1ml()} |
| @item @code{pow(), powf(), powl()} |
| @item @code{log(), logf(), logl()} |
| @item @code{log1p(), log1pf(), log1pl()} |
| @item @code{log2(), log2f(), log2l()} |
| @item @code{log10(), log10f(), log10l()} |
| @item @code{sqrt(), sqrtf(), sqrtl()} |
| @item @code{sin(), sinf(), sinl()} |
| @item @code{cos(), cosf(), cosl()} |
| @item @code{tan(), tanf(), tanl()} |
| @item @code{atan(), atanf(), atanl()} |
| |
| |
| @end itemize |