Changeset 7c25c3e in avrstuff


Ignore:
Timestamp:
Nov 28, 2012, 10:59:11 PM (11 years ago)
Author:
Adrien Destugues <pulkomandy@…>
Branches:
main
Children:
0853bac
Parents:
1d60f7b
Message:

PROGRESS!
With the fixed hardware, things are going much better...

Support for erasing and writing ROM 5 (as a test). Seems not very reliable yet, but mostly working.
I'll add a compare with source and see if I can find what's going wrong.

git-svn-id: ​svn://pulkomandy.tk/avrstuff@82 c6672c3c-f6b6-47f9-9001-1fd6b12fecbe

Location:
CPC stuff/gordon/manager
Files:
4 edited

Legend:

Unmodified
Added
Removed

  • CPC stuff/gordon/manager/Makefile

    r1d60f7b r7c25c3e  
    99# TODO use a target variable for the address, and get it from VASM/VLINK somehow
    1010$(NAME).BIN:: gordon.o
    11 $(NAME).BIN: START = 0x2000
     11$(NAME).BIN: START = 0x1800
    1212
    1313include cpc.mk

  • CPC stuff/gordon/manager/cpc.mk

    r1d60f7b r7c25c3e  
    3535
    3636# Assemble the sources
    37 %.o: %.z80
     37%.o: %.z80 Makefile
    3838        $(call BECHO,"Assembling $<...")
    3939        vasmz80_oldstyle -Fvobj -o $@ $<

  • CPC stuff/gordon/manager/gordon.z80

    r1d60f7b r7c25c3e  
    33; This program is distributed under the terms of the MIT licence
    44
    5 ; Start here.
     5        GLOBAL _start
     6
     7; Friendly firmware functions
     8getc    EQU     0xBB06
     9putc    EQU     0xBB5A
     10screenmem       EQU     0xBC08
     11
     12
     13; FIXME the plan is to have the same file behave both as a ROM and as an
     14; executable, so it can bootstrap itself into the megaflash. So we should start
     15; with a standard ROM header. RSXs to expose are :
     16; |BURN,"file",n (load file to &4000, then copy it to ROM n)
     17; |HIDE,n (write a FF as first byte in ROM to hide it from firmware)
     18; |HIDE (hides all ROMs)
     19; |SHOW,n (restore ROM n to visible state
     20; |SHOW (shows all ROMs)
     21; |KILL,n (erases ROM n)
     22
     23; This is the entry point when running as a standalone file
     24_start
     25        ; Ask the user to allow us to write to the flash memory
     26        LD HL,MSG_WRITE_START
     27        CALL puts
     28        CALL getc
     29        ; From there on, writing is enabled. This is ok as long as we don't
     30        ; connect a writable ROM ! When we do, we have to make sure NOTHING
     31        ; is read written from 8000-FFFF because the MegaFlash hardware
     32        ; doesn't decode A14 and will answer for the whole 32k range. This
     33        ; means, no use of firmware jumpblocks, and the stack needs to be
     34        ; moved elsewhere
     35
    636        DI
    7 
    8         LD HL, 0xC9FB
    9         LD (0x38), HL
    10 
    11 ; Move the screen to $8000 or $0000 so we can display things to the user, while
    12 ; C000 will write to the ROM and 4000 will hold the data to write... That could
    13 ; get a bit messy so maybe we will need to use the screen at 4000 as a buffer
    14 ; for the ROM data as well. Or just use a bank for that ?
    15         ; TODO
    16 
    17 ; Map the ROM in
    18         LD BC, 0x7F85
    19         OUT (C),C
    20 
    21 ; ask the user to enable writing
    22         ; TODO
    23 
    24 ; Turns out with the MegaFlash design, we can't both read and write. When the
    25 ; memory is in write mode, reading is disabled. This means we can't identify
    26 ; the chip, or use the data polling features. And we have to go for the
    27 ; worst-case timing given in the datasheet :(
    28 
    29 ; ... anyway, start with erasing the sectors we need.
    30         LD B, 4
     37        ; Move the stack away from the $8000-$FFFF area, since any write there
     38        ; will be intercepted by the Megaflash (it does not decode A14).
     39        LD (stack),SP
     40        LD SP,0x7FFF
     41
     42        ; Save the interrupt vector and replace it with EI/RET
     43        LD HL,(0x38)
     44          LD (inthandle),HL
     45        LD HL,0xC9FB
     46        LD (0x38),HL
     47
     48        ; TODO get the ROM number to burn somehow ?
     49        ; (we can get it as a CALL parameter)
     50
     51        CALL ERASE
     52        CALL WRITE
     53
     54        ; Disconnect the Megaflash
     55        LD BC,0xDFFF
     56        OUT (C),C
     57
     58        ; Restore the firmware in working order now that we are done
     59        LD SP,(stack)
     60          LD HL,(inthandle)
     61          LD (0x38),HL
     62        EI
     63
     64        ; Tell firmware to draw the screen at &4000 (so we don't erase the
     65          ; ROM with the next message...)
     66        LD A,0x40
     67        CALL screenmem
     68
     69        LD HL,MSG_WRITE_END
     70        CALL puts
     71        ; Wait for key
     72        CALL 0xBB06
     73
     74        ; Put screen back at normal address
     75        LD A,0xC0
     76        CALL screenmem
     77
     78        ; TODO cleanly get out (and handle both calls by RUN and CALL)
     79        JR $
     80
     81; Erase a 16K ROM. Input:
     82; A - ROM number to erase (TODO)
     83; Assumes we are in write mode, interrupts disabled.
    3184ERASE
    32         PUSH BC
     85          LD B,4
     86eraseloop
     87          PUSH BC
    3388
    3489        LD A, 0x80 ; ERASE
    … …  
    51106
    52107        LD H,A
    53 
     108        LD L,0
     109
     110        ; Sector erase command
    54111        LD E, 0x30
    55112        LD (HL), E
    56113
    57         ; This will delay long enough - we need at least 25ms
     114        ; This will delay long enough - we need at least 20ms
    58115        EI
    59116        HALT
    … …  
    61118        HALT
    62119        HALT
     120        HALT
     121          HALT
     122        HALT
    63123        DI
    64124
    65         DJNZ ERASE
    66 
     125        DJNZ eraseloop
     126
     127        RET
     128
     129
     130; Write a 16K ROM
     131; IN: A     - ROM number to write (TODO)
     132;     &2000 - Data to copy (TODO let the caller put that in IX maybe ?)
     133; Assumes we are in write-enabled mode (TODO)
     134WRITE
    67135; Ok, now that we erased the 4 sectors we needed, we can write data to them
    68136        LD HL, 0xC000
    69         LD IX, 0x4000
     137        LD IX, 0x2000
    70138PROGRAM
    71         LD A, 0xA0 ; BYTE PROGRAM ;     2       10
    72         PUSH HL                                   ;     3       13
    73         CALL send_command                 ; 5   18
     139          PUSH HL
     140
     141        LD A, 0xA0 ; BYTE PROGRAM
     142        CALL send_command
     143
     144        POP HL
    74145
    75146        LD B,0xDF
    … …  
    77148        OUT (C),C
    78149
    79         POP HL
    80 
    81150        LD A,(IX + 0)
    82         LD (HL),A               ; Write occurs here. Need to wait 20 NOPs before next
    83                                         ; operation on ROM. Our code is slow enough already !
    84 
    85         INC IX                                  ;       3       5
    86         INC HL                                  ;       2       2
    87 
     151        LD (HL),A       ; Write occurs here. Need to wait 20 NOPs before next
     152                ; operation on ROM. Our code is slow enough already !
     153
     154        INC IX
     155        INC HL
     156
     157        ; As INC HL doesn't update the flags, check if we overflowed yet
    88158        LD A,H
    89159        OR L
    90160
    91         JR NZ, PROGRAM                  ;       3       8
    92 
    93         JR $
    94 
    95 ; Now reuse and adapt the code from OUL guys !
    96         ; TODO
    97 
    98 ; That's all folks !
     161        JR NZ, PROGRAM
     162
    99163        RET
    100164
    … …  
    113177
    114178        ; Select ROM 1 again and write the command to address 0xEAAA
    115         INC C
     179        DEC C
    116180        OUT (C),C
    117181        EX DE,HL
    … …  
    137201
    138202        ; Select ROM 2 and write 0x55 to address 0xEAAA
    139         DEC C
     203        INC C
    140204        OUT (C),C
    141205        EX DE,HL
    … …  
    145209
    146210
    147 ; Print value of A, as 2 hex digits
    148 printhex
     211; Write message pointed by HL to screen
     212puts
     213        LD A,(HL)
     214        INC HL
     215        CALL &BB5A
     216        OR A
     217        JR NZ,puts
     218        RET
     219
     220; -----------------------------------------------------------------------------
     221; Messages
     222MSG_WRITE_START string "Turn write switch ON and press a key...\r\n"
     223MSG_WRITE_END string "Turn write switch OFF and press a key...\r\n"
     224
     225; -----------------------------------------------------------------------------
     226        SECTION .uninit,"urw"
     227
     228stack   DEFW    1
     229inthandle       DEFW    1
     230
     231        end
     232
     233; Very basic command prompt/monitor stuff for testing
     234        ; Print prompt
     235        LD A,'?'
     236        CALL 0xBB5A
     237        ; Wait for key
     238        CALL 0xBB06
     239        ; Parse commands
     240        CP A,'d'
     241        JP Z,DUMP
     242        CP A,'e'
     243        JP Z,ERASE
     244        CP A,'w'
     245        JP Z,WRITE
     246
     247        ; Unhandled command
     248        LD A,'X'
     249        CALL 0xBB5A
     250
     251        ; Start over
     252        JR _start
     253
     254
     255; Dump some bytes from beginning of ROM 5
     256DUMP
     257        DI
     258
     259; Map the ROM in (stay in mode 1 and get system rom out)
     260        LD BC, 0x7F85
     261        OUT (C),C
     262
     263        LD BC,0xDF05
     264        OUT (C),C
     265
     266; Copy the ROM to RAM
     267        LD DE, 0x4000
     268        LD BC, 0x4000
     269        LD HL, 0xC000
     270        LDIR
     271
     272        EI
     273
     274; Dump the RAM (we're safe if the system maps another ROM this way)
     275        LD HL,0x4000
     276plop
     277        LD A,(HL)
     278        INC HL
     279        CALL PRNHEX2
     280        DJNZ plop
     281
     282; Wait for next command
     283        JP _start
     284
     285
     286PRNHEX2                 ;affiche la valeur de A sur 2 chiffres
     287;     en hexad{cimal
    149288        PUSH    AF
    150289        RRA     
    … …  
    163302;on a le code ascii du chiffre @ afficher
    164303        JP      0xBB5A  ;call-ret
    165 ;
     304
     305
     306PRNHEX2                 ;affiche la valeur de A sur 2 chiffres
     307;     en hexad{cimal
     308        PUSH    AF
     309        RRA     
     310        RRA     
     311        RRA     
     312        RRA             ;divise A par 8
     313        CALL    PRNHEX1 ;affiche le premier morceau
     314        POP     AF      ;r{cup la valeur originale pour la suit
     315PRNHEX1                 ;affiche la valeur de A sur 1 chiffre
     316;affiche A sur 1 chiffre en Hexa
     317        AND     0xF     ;ne prend que les unit{s
     318        OR      A
     319        DAA             ;convertit en d{cimal 
     320        ADD     A,0xF0  ;ajoute 240
     321        ADC     A,0x40  ;ajoute 64+le carry (si >15)
     322;on a le code ascii du chiffre @ afficher
     323        JP      0xBB5A  ;call-ret
     324
     325

  • CPC stuff/gordon/manager/link.ld

    r1d60f7b r7c25c3e  
    11SECTIONS {
    22        .text: { *(.text) }
    3         . = MAX(.,0x3FFC);
    4         .romcalls: { *(.romcalls) }
     3        .uninit: { *(.uninit) }
    54}
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