Add rErrno variable to relocator

0 is used as error condition, so add a way to pass some more
detailed error information to the caller.

reloc.S

@@ -67,9 +67,10 @@ HunkLoop
 
         ; We don't know this hunk
 RelocateFail
+        ; Save hunk number in rErrno as error code
+        lea     _rErrno(pc),a0
+        move.l  d0,(a0)
         bsr     RelocateCleanup
-        ; Save hunk number in d1 as error code
-        move.l  d0,d1
         moveq.l #0,d0 ; NULL = Failure
         rts
 
@@ -145,7 +146,11 @@ SkipSymbol
 HunkEnd
         addq.l  #4,a5
         dbra    d6,HunkLoop
-        moveq.l #$0,d0
+
+        lea     _rErrno(pc),a0
+        moveq.l #0,d0
+        move.l  d0,(a0)
+
         bsr.s   CreateSegList
         move.l  _pHunks(pc),a0
         move.l  (a0),d2
@@ -264,4 +269,7 @@ ReadHandle
 _pHunks
         dc.l    0
 
+        public _rErrno
+_rErrno
+        dc.l    0
         CODE

reloctest.c

@@ -9,6 +9,7 @@
 
 #include <clib/exec_protos.h>
 uint32_t relocate(ULONG offset asm("d0"), uint8_t *program asm("a0"));
+extern uint32_t rErrno;
 extern uint8_t  device[];
 
 static void hexdump(unsigned char *data, size_t size)
@@ -51,7 +52,7 @@ int main(int argc, char *argv[])
 
 	printf("Calling relocate()\n");
 	ret=relocate(0, device);
-	printf("... relocate returned %x\n", ret);
+	printf("... relocate returned %x (rErrno=0x%x)\n", ret, rErrno);
 
 	seg=(uint32_t *)ret;