From f28f97241c95b6434d9a326d8349f25cd16bebfb Mon Sep 17 00:00:00 2001
From: Adrien Destugues <pulkomandy@pulkomandy.tk>
Date: Fri, 22 Jan 2016 21:01:19 +0100
Subject: Import Kevin Thacker patch for runtime relocation support.


diff --git a/sdas/linksrc/Makefile.in b/sdas/linksrc/Makefile.in
index 56537a5..35f1922 100644
--- a/sdas/linksrc/Makefile.in
+++ b/sdas/linksrc/Makefile.in
@@ -47,7 +47,7 @@ ASXXLIBSRC = strcmpi.c
 SRC = lk_readnl.c lkaomf51.c lkar.c lkarea.c lkdata.c lkelf.c lkeval.c \
         lkhead.c lklex.c lklib.c lklibr.c lklist.c lkmain.c lkmem.c \
         lknoice.c lkout.c lkrel.c lkrloc.c lkrloc3.c lks19.c lksdcclib.c \
-        lksym.c sdld.c lksdcdb.c lkbank.c
+        lksym.c sdld.c lksdcdb.c lkbank.c lkrrel.c
 
 LKSOURCES = $(SRC) $(ASXXLIBSRC:%.c=$(ASXXLIB)/%.c)
 
diff --git a/sdas/linksrc/aslink.h b/sdas/linksrc/aslink.h
index e0865f8..d9f6316 100644
--- a/sdas/linksrc/aslink.h
+++ b/sdas/linksrc/aslink.h
@@ -1033,6 +1033,8 @@ extern  int     yflag;          /*      -y, enable SDCC Debug output
                                  */
 #endif
 
+extern  int     hflag;          /*      Generate relocatable executable
+								 */
 extern  int     pflag;          /*      print linker command file flag
                                  */
 extern  int     uflag;          /*      Listing relocation flag
diff --git a/sdas/linksrc/lkdata.c b/sdas/linksrc/lkdata.c
index bb83900..bfaa197 100644
--- a/sdas/linksrc/lkdata.c
+++ b/sdas/linksrc/lkdata.c
@@ -66,6 +66,9 @@ int     oflag;          /*      Output file type flag
 int     objflg;         /*      Linked file/library object output flag
                          */
 
+int     hflag;          /*      Generate relocatable executable
+						 */
+
 #if NOICE
 int     jflag;          /*      NoICE output flag
                          */
diff --git a/sdas/linksrc/lkmain.c b/sdas/linksrc/lkmain.c
index 1cc7a45..9d6f916 100644
--- a/sdas/linksrc/lkmain.c
+++ b/sdas/linksrc/lkmain.c
@@ -233,6 +233,7 @@ main(int argc, char *argv[])
         startp->f_idp = "";
 
         pflag = 1;
+		hflag = 0;
 
         for(i=1; i<argc; i++) {
                 ip = ib;
@@ -960,6 +961,11 @@ parse()
                                         }
                                         return(0);
 
+								case 'h':
+								case 'H':
+										hflag = 1;
+										break;
+
                                 case 'I':
                                         if (is_sdld() && !(TARGET_IS_Z80 || TARGET_IS_GB)) {
                                                 iramsav();
diff --git a/sdas/linksrc/lkrloc3.c b/sdas/linksrc/lkrloc3.c
index cf184f2..6f11cdc 100644
--- a/sdas/linksrc/lkrloc3.c
+++ b/sdas/linksrc/lkrloc3.c
@@ -31,6 +31,7 @@
  */
 
 #include "aslink.h"
+#include "lkrrel.h"
 
 /*)Module       lkrloc3.c
  *
@@ -332,6 +333,9 @@ relr3(void)
          * Do remaining relocations
          */
         while (more()) {
+				int output_relocation_record;
+				int raddr;
+
                 error = 0;
                 mode = (int) eval();
 
@@ -390,6 +394,95 @@ relr3(void)
                         reli -= paga + pags;
                 }
 
+		/* KevT 28-05-2005 */
+
+		if (hflag)
+		{
+		output_relocation_record = 0;
+		if (mode & R3_SYM)
+		{
+			/* If the symbol is defined in a absolute area, then we do not
+			output a record. This allows us to reference absolute addresses
+			in our code, but it can still be relocated */
+
+			/* If the symbol is relative, it is within our relocatable program */
+
+			/* printf("Symbol: %s\n",s[rindex]->s_id); */
+			if ((s[rindex]->s_axp->a_bap->a_flag & A4_ABS)==0)
+			{
+				output_relocation_record=1;
+			}
+		}
+		else
+		{
+			/* If the area is absolute then we do not output a record.
+			This allows us to reference absolute memory, but still the code
+			can be relocated. */
+			/* If the area is relative, it refers to data that is part of the 
+			relocatable program */
+
+			/* printf("Area: %s\n",a[rindex]->a_bap->a_id); */
+			if ((a[rindex]->a_bap->a_flag & A4_ABS)==0)
+			{
+				output_relocation_record=1;
+			}
+		}
+		
+		if (output_relocation_record)
+		{
+			a_uint relocate_address = pc+(rtp-rtofst);
+			if (hilo)
+			{
+				raddr = reli + ((rtval[rtp]&0x0ff)<<8) + (rtval[rtp+1]&0x0ff);
+			}
+			else
+			{
+				raddr = reli + ((rtval[rtp+1]&0x0ff)<<8) + (rtval[rtp]&0x0ff);
+			}
+			/*printf("Relocation modify address: %04x\n",relocate_address); */
+			/*printf("Relocation address: %04x\n",raddr); */
+			if (mode & R3_BYTE)
+			{
+				if (mode & R3_BYTX)
+				{
+					if (mode & R3_MSB)
+					{
+						
+relrec8hi(relocate_address,raddr);
+					}
+					else
+					{
+						
+relrec8lo(relocate_address,raddr);
+					}
+				}
+				else
+				{
+					printf("not supported");
+				}
+			}
+			else
+			{
+				if (mode & R3_BYTX) 
+				{
+					if (mode & R3_MSB) 
+					{
+						printf("not supported");
+					}
+					else
+					{
+						printf("not supported");
+					}
+				}	
+				else
+				{
+					relrec16(relocate_address);
+				}
+			}
+		}		
+		}
+
+
                 /*
                  * R3_BYTE or R3_WORD operation
                  */
@@ -755,6 +848,12 @@ rele3()
         if (uflag != 0) {
                 lkulist(0);
         }
+
+		/* output relocation data */
+		if (hflag) {
+			relrecwrite();
+		}
+
         if (oflag != 0) {
                 lkflush();
                 lkfclose();
diff --git a/sdas/linksrc/lkrrel.c b/sdas/linksrc/lkrrel.c
new file mode 100644
index 0000000..e9e8383
--- /dev/null
+++ b/sdas/linksrc/lkrrel.c
@@ -0,0 +1,251 @@
+/* (c) Kevin Thacker, May 2005 */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "aslink.h"
+#include "lkrrel.h"
+
+struct relrechead
+{
+	int count;
+	struct relrec *head;
+};
+
+/* 16-bit values, add full 16-bit base address */
+
+static struct relrechead head16= {0,NULL};
+/* 8-bit, but add high byte of 16-bit base address */
+static struct relrechead head8hi = {0,NULL};
+/* 8-bit, but add low byte of 16-bit base address */
+static struct relrechead head8lo = {0,NULL};
+
+/* internal; free's list */
+static void relrecfree(struct relrechead *head)
+{
+	struct relrec *cur = head->head;
+	
+	while (cur!=NULL)
+	{
+		struct relrec *next = cur->next;
+		free(cur);
+
+		cur = next;
+	}
+}
+
+/* free relocation record list; e.g. on exit */
+void freerelrec()
+{
+	relrecfree(&head16);
+	relrecfree(&head8hi);
+	relrecfree(&head8lo);
+}
+
+/* internal; allocate a relocation record */
+static void newrelrec(struct relrechead *head, a_uint addr, a_uint symaddr)
+{
+	struct relrec *rec;
+	
+	rec  = (struct relrec *) malloc(sizeof(struct relrec));
+	
+	/* error if allocation failed */
+	if (rec==NULL)
+		return;
+
+	rec->addr = addr;
+	rec->symaddr = symaddr;
+	
+	/* add to start of list */
+	rec->next = head->head;
+	head->head = rec;
+	head->count++;
+}
+	
+/* add item to 16-bit relocation record list */
+void relrec16(a_uint addr)
+{
+	newrelrec(&head16, addr,0);
+}
+
+/* add item to 8-bit (high) relocation record list */
+void relrec8hi(a_uint addr, a_uint symaddr)
+{
+	newrelrec(&head8hi, addr,symaddr);
+}
+
+/* add address to 8-bit (low) relocation list */
+void relrec8lo(a_uint addr, a_uint symaddr)
+{
+	newrelrec(&head8lo, addr,symaddr);
+}
+
+/* internal; compare two addresses within two relocate records */ 
+static int relreccompare(const void *a, const void *b)
+{
+	const struct relrec *relreca = (const struct relrec *)a;
+	const struct relrec *relrecb = (const struct relrec *)b;
+
+	return (relreca->addr-relrecb->addr);
+}
+
+/* sort a list of relocate records and return an array of the records */
+static struct relrec *relrecsort(struct relrechead *head)
+{
+	int count;
+	struct relrec *reclist;
+	struct relrec *cur;
+
+	if (head->count==0)
+		return NULL;
+
+	/* allocate list to hold all items */
+	reclist = (struct relrec *)malloc(sizeof(struct relrec)*head->count);	
+
+	if (reclist==NULL)
+		return NULL;
+
+	/* fill list */
+	count = 0;
+	cur = head->head;
+	while (cur!=NULL)
+	{
+		memcpy(&reclist[count],cur,sizeof(struct relrec));
+		count++;
+		cur = cur->next;
+	}
+
+	/* sort into ascending address order */
+	qsort(reclist, count, sizeof(struct relrec),relreccompare);
+
+	return reclist;
+}
+
+int outbyte(int addr, char byte)
+{
+	rtval[0] = addr&0x0ff;
+	rtval[1] = (addr>>8)&0x0ff;
+	rtval[2] = byte&0x0ff;
+	addr+=1;		
+	rtflg[0] = 1;
+	rtflg[1] = 1;
+	rtflg[2] = 1;
+	rtcnt = 3;
+	ixx(1);
+	return addr;
+}
+
+void relrecwritelist1(struct relrechead *list,int *addrptr)
+{
+	int i;
+	struct relrec *relreclist;
+	int addr;
+
+	addr = *addrptr;
+
+	relreclist = relrecsort(list);
+
+	if (relreclist!=NULL)
+	{
+		int prevaddr = 0;
+		for (i=0; i<list->count; i++)
+		{
+			struct relrec *cur = &relreclist[i];
+
+			int delta = cur->addr-prevaddr;
+			
+			if (delta>254)
+			{
+				int largedelta = delta-1;
+				addr = outbyte(addr,0x0ff);
+				addr = outbyte(addr,largedelta&0x0ff);
+				addr = outbyte(addr,(largedelta>>8)&0x0ff);
+				delta = 1;
+			}
+			prevaddr = cur->addr;
+			addr = outbyte(addr,delta&0x0ff);
+		}	
+	
+		free(relreclist);
+	}
+	
+	addr = outbyte(addr, 0);
+	
+	*addrptr = addr;
+
+}
+
+void relrecwritelist2(struct relrechead *list,int *addrptr)
+{
+	int i;
+	struct relrec *relreclist;
+	int addr;
+
+	addr = *addrptr;
+
+	relreclist = relrecsort(list);
+
+	if (relreclist!=NULL)
+	{
+		int prevaddr = 0;
+		for (i=0; i<list->count; i++)
+		{
+			struct relrec *cur = &relreclist[i];
+			int delta = cur->addr-prevaddr;
+			prevaddr = cur->addr;
+			
+			if (delta>254)
+			{
+				int largedelta = delta-1;
+				addr = outbyte(addr,0x0ff);
+				addr = outbyte(addr,largedelta&0x0ff);
+				addr = outbyte(addr,(largedelta>>8)&0x0ff);
+				delta = 1;
+			}
+
+			addr = outbyte(addr,delta&0x0ff);
+			addr = outbyte(addr,cur->symaddr&0x0ff);
+		}	
+	
+		free(relreclist);
+	}
+
+	addr = outbyte(addr,0);
+	
+	*addrptr = addr;
+
+}
+
+
+void relrecwrite()
+{
+	int areasize = 0;
+
+	struct area *cur = areap;
+	while (cur!=NULL)
+	{
+		areasize+=cur->a_size;
+		cur=cur->a_ap;
+	}
+
+	//printf("total length before relocation records: %04x\n",areasize);
+
+	/* re-write offset to relocation records */
+	rtval[0] = 0;
+	rtval[1] = 0;
+	rtval[2] = areasize&0x0ff;
+	rtval[3] = (areasize>>8)&0x0ff;
+	rtflg[0] = 1;
+	rtflg[1] = 1;
+	rtflg[2] = 1;
+	rtflg[3] = 1;
+	rtcnt = 4;
+	ixx(1);
+	
+
+	int addr = areasize;
+
+
+	relrecwritelist1(&head16,&addr);
+	relrecwritelist1(&head8lo,&addr);
+	relrecwritelist2(&head8hi,&addr);
+}
diff --git a/sdas/linksrc/lkrrel.h b/sdas/linksrc/lkrrel.h
new file mode 100644
index 0000000..ca1cfd4
--- /dev/null
+++ b/sdas/linksrc/lkrrel.h
@@ -0,0 +1,17 @@
+/* relocation record */
+struct relrec
+{
+	/* next item */
+	struct relrec *next;
+
+	/* address of relocate */
+	a_uint addr;
+
+	a_uint symaddr;
+};
+
+void relrec16(a_uint addr);
+void relrec8lo(a_uint addr, a_uint symaddr);
+void relrec8hi(a_uint addr, a_uint symaddr);
+void freerelrec();
+void relrecwrite();
-- 
2.7.0