output of elf2mac is now a piece of code with no headers with its entry point at the start. No more FLT file format.

Elf2Mac/Elf2Mac.cc

@@ -141,39 +141,23 @@ void ElfToFlt(string input, string output)
 
 	std::sort(relocs.begin(), relocs.end());
 
-	ofstream out(output);
-
-	byte(out, 'b');
-	byte(out, 'F');
-	byte(out, 'L');
-	byte(out, 'T');
-	longword(out, 4);
-	longword(out, 0x40 + ehdr.e_entry);	// entry point
 
 	GElf_Shdr text_shdr, data_shdr, bss_shdr;
 	gelf_getshdr(codeSections[".text"], &text_shdr);
 	gelf_getshdr(codeSections[".data"], &data_shdr);
 	gelf_getshdr(bssSection, &bss_shdr);
 
-	longword(out, 0x40 + data_shdr.sh_addr); // data start
-	longword(out, 0x40 + bss_shdr.sh_addr);	// data end
-	longword(out, 0x40 + bss_shdr.sh_addr + bss_shdr.sh_size);	// bss end
-	longword(out, 4096); // stack size, ignored
-	longword(out, 0x40 + bss_shdr.sh_addr); // relocStart);
-	longword(out, relocs.size());
-	longword(out, 0); // flags
-	for(int i = 0; i < 6; i++)
-		longword(out, 0); // filler
+	ofstream out(output);
 
 	Elf_Data *data = elf_getdata(codeSections[".text"], NULL);
 	out << string((char*)data->d_buf, (char*)data->d_buf + data->d_size);
 
-	while(out.tellp() < 0x40 + data_shdr.sh_addr)
+	while(out.tellp() < /*0x40 + */data_shdr.sh_addr)
 		byte(out, 0x00);
 	data = elf_getdata(codeSections[".data"], NULL);
 	out << string((char*)data->d_buf, (char*)data->d_buf + data->d_size);
 
-	while(out.tellp() < 0x40 + bss_shdr.sh_addr)
+	while(out.tellp() < /*0x40 +*/ bss_shdr.sh_addr)
 		byte(out, 0x00);
 	for(int reloc : relocs)
 		longword(out, reloc);

Elf2Mac/LdScript.cc

@@ -28,6 +28,19 @@ SECTIONS
     .text :	{
         _stext = . ;
         PROVIDE(_rsrc_start = .);
+        *(.rsrcheader)
+        
+        . = ALIGN (2);
+        _entry_trampoline = .;
+        SHORT(DEFINED(__break_on_entry) ? 0xA9FF : 0x4e71);
+        LONG(0x61000002);	/* bsr *+2 */
+        SHORT(0x0697); /* addi.l #_, (a7) */
+        LONG(_start - _entry_trampoline - 6);
+        SHORT(0x4e75); /* rts */
+
+        *(.relocvars)
+        */libretrocrt.a:start.c.obj(.text*)
+        */libretrocrt.a:relocate.c.obj(.text*) 
         */libretrocrt.a:*(.text*)
         *(.text*)
 

libretro/Retro68.r

@@ -16,17 +16,8 @@ jtend:
 
 #define RETRO68_CODE_TYPE	\
 		hex string dontBreakAtEntry = $"", breakAtEntry = $"A9FF";	\
-		longint = 0x61000002;	/* bsr *+2 */	\
-	relativeTo:	\
-		integer = 0x0697; /* addi.l #_, (a7) */ \
-		longint = $$long(fltfile + 8*8) + (fltfile-relativeTo)/8;	\
-		integer = 0x4e75; /* rts */	\
-		longint = fltfile/8;	\
-	fltfile:					\
 		hex string;
 
-
-
 type 'CODE' (1) {
 	integer = 0;
 	integer = 1;

libretro/relocate.c

@@ -40,9 +40,16 @@ typedef void (*voidFunction)(void);
 /*
    Linker-defined addresses in the binary;
  */
+
+// section boundaries
 extern uint8_t _stext, _etext, _sdata, _edata, _sbss, _ebss;
+// constructor list:
 extern uint8_t __init_section, __init_section_end;
+// destructor list:
 extern uint8_t __fini_section, __fini_section_end;
+// address of start of code reource.
+// usually equal to _stext, but can be overridden.
+extern uint8_t _rsrc_start;
 
 typedef struct Retro68RelocState
 {
@@ -50,7 +57,7 @@ typedef struct Retro68RelocState
 	Handle codeHandle;
 } Retro68RelocState;
 
-static Retro68RelocState relocState __attribute__ ((nocommon, section(".text"))) = {
+static Retro68RelocState relocState __attribute__ ((section(".relocvars"))) = {
 	NULL, NULL
 };
 
@@ -149,18 +156,15 @@ void Retro68Relocate()
 	log(orig_ebss);
 	
 	uint8_t *base = orig_stext + displacement;
-	// Recover the handle to the code resource by looking at the
-	// longword before the FLT header. The resource templates in Retro68.r store the offset
-	// from the beginning of the code resource there.
-	uint32_t offsetInResource = *(uint32_t*)(base - 0x44) + 0x40;
 	
-	if(offsetInResource < 4096)
-		// Arbitrary magic number. We expect the offset to be small, just a few header bytes before it.
-		// if it's out of range, assume the longword before the header is not the offset we're looking for.
-	{   
-		Handle h = RecoverHandle((Ptr) base - offsetInResource);        
+	{
+		uint8_t *orig_rsrc_start;
+		GET_VIRTUAL_ADDRESS(orig_rsrc_start, _rsrc_start);
+		uint8_t *rsrc_start = orig_rsrc_start + displacement;
+		
+		Handle h = RecoverHandle((Ptr) rsrc_start);        
 		if(MemError() == noErr && h)
-		{                    
+		{
 			// Make sure the code is locked. Only relevant for some code resources.
 			HLock(h);
 			rState->codeHandle = h;  
@@ -185,9 +189,7 @@ void Retro68Relocate()
 		bss_displacement = (uint8_t*)rState->bssPtr - orig_sbss;
 	}
 
-	long i;
 	// Process relocation records
-	
 	for(long *reloc = (long*)( base + text_and_data_size );
 		*reloc != -1;
 		++reloc)
@@ -215,7 +217,7 @@ void Retro68Relocate()
 
 		WRITE_UNALIGNED_LONGWORD(addrPtr, (uint32_t) addr);
 	}
-	
+
 	// We're basically done.
 	// Now check whether we're on 68040 or later and need to flush the cache.
 	// only do this if SysEnvirons is available.