opencode.energia.arti.ee/2ine-tms34010
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Changed asm for 16-bit missing trampolines to escape 16-bit mode first.

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Ryan C. Gordon committed 2018-06-06 17:17:12 -04:00
1 parent 8b695647db
commit 4cbda8515b
1 file changed
+35 -22
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lx_loader.c
+35 -22
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@@ -731,25 +731,29 @@ static void *generateMissingTrampoline16(const char *_module, const char *_entry
char *module = strdup(_module);
char *entry = strdup(_entry);
// convert stack to linear address...
*(ptr++) = 0x8C; /* mov ax,ss... */
*(ptr++) = 0xD0; /* ...mov ax,ss */
*(ptr++) = 0xC1; /* shr ax,byte 0x3... */
*(ptr++) = 0xE8; /* ...shr ax,byte 0x3 */
*(ptr++) = 0x03; /* ...shr ax,byte 0x3 */
*(ptr++) = 0x66; /* shl eax,byte 0x10... */
*(ptr++) = 0xC1; /* ...shl eax,byte 0x10 */
*(ptr++) = 0xE0; /* ...shl eax,byte 0x10 */
*(ptr++) = 0x10; /* ...shl eax,byte 0x10 */
*(ptr++) = 0x89; /* mov ax,sp... */
*(ptr++) = 0xE0; /* ...mov ax,sp */
// jmp to 32-bit code...
// USE16
*(ptr++) = 0x89; /* mov cx,sp... */
*(ptr++) = 0xE1; /* ...mov cx,sp */
*(ptr++) = 0x66; /* jmp dword 0x7788:0x33332222... */
*(ptr++) = 0xEA; /* ...jmp dword 0x7788:0x33332222 */
const uint32 jmp32addr = (uint32) (ptr + 6);
memcpy(ptr, &jmp32addr, 4); ptr += 4;
memcpy(ptr, &GLoaderState.original_cs, 2); ptr += 2;
// now we're in 32-bit land again.
// USE32
*(ptr++) = 0x66; /* mov ax,ss... */
*(ptr++) = 0x8C; /* ...mov ax,ss */
*(ptr++) = 0xD0; /* ...mov ax,ss */
*(ptr++) = 0x66; /* shr ax,byte 0x3... */
*(ptr++) = 0xC1; /* ...shr ax,byte 0x3 */
*(ptr++) = 0xE8; /* ...shr ax,byte 0x3 */
*(ptr++) = 0x03; /* ...shr ax,byte 0x3 */
*(ptr++) = 0xC1; /* shl eax,byte 0x10... */
*(ptr++) = 0xE0; /* ...shl eax,byte 0x10 */
*(ptr++) = 0x10; /* ...shl eax,byte 0x10 */
*(ptr++) = 0x66; /* mov ax,cx... */
*(ptr++) = 0x89; /* ...mov ax,cx */
*(ptr++) = 0xC8; /* ...mov ax,cx */
*(ptr++) = 0x66; /* mov cx,0xabcd... */
*(ptr++) = 0xB9; /* ...mov cx,0xabcd */
memcpy(ptr, &GLoaderState.original_ss, 2); ptr += 2;
@@ -757,14 +761,23 @@ static void *generateMissingTrampoline16(const char *_module, const char *_entry
*(ptr++) = 0xD1; /* ...mov ss,ecx */
*(ptr++) = 0x89; /* mov esp,eax... */
*(ptr++) = 0xC4; /* ...mov esp,eax */
*(ptr++) = 0x66; /* mov cx,0x8888... */
*(ptr++) = 0xB9; /* ...mov cx,0x8888 */
memcpy(ptr, &GLoaderState.original_ds, 2); ptr += 2;
*(ptr++) = 0x66; /* mov cx,0x8888... */
*(ptr++) = 0xB9; /* ...mov cx,0x8888 */
memcpy(ptr, &GLoaderState.original_es, 2); ptr += 2;
*(ptr++) = 0x8E; /* mov es,ecx... */ \
*(ptr++) = 0xC1; /* ...mov es,ecx */ \
if (GLoaderState.original_ss != GLoaderState.original_ds) {
*(ptr++) = 0x66; /* mov cx,0x8888... */
*(ptr++) = 0xB9; /* ...mov cx,0x8888 */
memcpy(ptr, &GLoaderState.original_ds, 2); ptr += 2;
}
*(ptr++) = 0x8E; /* mov ds,ecx... */
*(ptr++) = 0xD9; /* ...mov ds,ecx */
if (GLoaderState.original_es != GLoaderState.original_ds) {
*(ptr++) = 0x66; /* mov cx,0x8888... */
*(ptr++) = 0xB9; /* ...mov cx,0x8888 */
memcpy(ptr, &GLoaderState.original_es, 2); ptr += 2;
}
*(ptr++) = 0x8E; /* mov es,ecx... */
*(ptr++) = 0xC1; /* ...mov es,ecx */
// okay, CPU is in a sane state again, call the trampoline. Don't bother cleaning up.
*(ptr++) = 0x68; // pushl immediate
memcpy(ptr, &entry, sizeof (char *));