M src/arm.c → src/arm.c

@@ -106,3 +106,10 @@
 	cpu->board->reset(cpu->board);
 }
 
+void ARMRun(struct ARMCore* cpu) {
+	if (cpu->executionMode) {
+		ThumbStep(cpu);
+	} else {
+		ARMStep(cpu);
+	}
+}

M src/arm.h → src/arm.h

@@ -116,4 +116,6 @@
 void ARMReset(struct ARMCore* cpu);
 void ARMSetPrivilegeMode(struct ARMCore*, enum PrivilegeMode);
 
+void ARMRun(struct ARMCore* cpu);
+
 #endif

M src/isa-thumb.c → src/isa-thumb.c

@@ -4,6 +4,15 @@ #include "isa-inlines.h"
 
 static const ThumbInstruction _thumbTable[0x400];
 
+void ThumbStep(struct ARMCore* cpu) {
+	uint32_t address = cpu->gprs[ARM_PC];
+	cpu->gprs[ARM_PC] = address + WORD_SIZE_THUMB;
+	address -= WORD_SIZE_THUMB;
+	uint16_t opcode = ((uint16_t*) cpu->memory->activeRegion)[(address & cpu->memory->activeMask) >> 1];
+	ThumbInstruction instruction = _thumbTable[opcode >> 6];
+	instruction(cpu, opcode);
+}
+
 // Instruction definitions
 // Beware pre-processor insanity
 

M src/main.c → src/main.c

@@ -15,7 +15,7 @@ gba.cpu.gprs[ARM_PC] = 0x08000004;
 	gba.memory.d.setActiveRegion(&gba.memory.d, gba.cpu.gprs[ARM_PC]);
 	int i;
 	for (i = 0; i < 1024 * 1024 * 16; ++i) {
-		ARMStep(&gba.cpu);
+		ARMRun(&gba.cpu);
 	}
 	GBADeinit(&gba);
 	close(fd);