M src/gba/gba-thread.c → src/gba/gba-thread.c

@@ -146,7 +146,7 @@ }
 
 	if (threadContext->rom) {
 		GBALoadROM(&gba, threadContext->rom, threadContext->save, threadContext->fname);
-		if (threadContext->bios) {
+		if (threadContext->bios && GBAIsBIOS(threadContext->bios)) {
 			GBALoadBIOS(&gba, threadContext->bios);
 		}
 

M src/gba/gba.c → src/gba/gba.c

@@ -680,6 +680,23 @@ }
 	return memcmp(signature, GBA_ROM_MAGIC, sizeof(signature)) == 0;
 }
 
+bool GBAIsBIOS(struct VFile* vf) {
+	if (vf->seek(vf, 0, SEEK_SET) < 0) {
+		return false;
+	}
+	uint32_t interruptTable[7];
+	if (vf->read(vf, &interruptTable, sizeof(interruptTable)) != sizeof(interruptTable)) {
+		return false;
+	}
+	int i;
+	for (i = 0; i < 7; ++i) {
+		if ((interruptTable[i] & 0xFFFF0000) != 0xEA000000) {
+			return false;
+		}
+	}
+	return true;
+}
+
 void GBAGetGameCode(struct GBA* gba, char* out) {
 	memcpy(out, &((struct GBACartridge*) gba->memory.rom)->id, 4);
 }

M src/gba/gba.h → src/gba/gba.h

@@ -170,6 +170,7 @@ void GBALoadBIOS(struct GBA* gba, struct VFile* vf);
 void GBAApplyPatch(struct GBA* gba, struct Patch* patch);
 
 bool GBAIsROM(struct VFile* vf);
+bool GBAIsBIOS(struct VFile* vf);
 void GBAGetGameCode(struct GBA* gba, char* out);
 void GBAGetGameTitle(struct GBA* gba, char* out);