1#include "arm.h"
 2
 3static void _ARMSetMode(struct ARMCore*, enum ExecutionMode);
 4static ARMInstruction _ARMLoadInstructionARM(struct ARMMemory*, uint32_t address);
 5static ARMInstruction _ARMLoadInstructionThumb(struct ARMMemory*, uint32_t address);
 6
 7static void _ARMSetMode(struct ARMCore* cpu, enum ExecutionMode executionMode) {
 8	if (executionMode == cpu->executionMode) {
 9		return;
10	}
11
12	cpu->executionMode = executionMode;
13	switch (executionMode) {
14	case MODE_ARM:
15		cpu->cpsr.t = 0;
16		cpu->instructionWidth = WORD_SIZE_ARM;
17		cpu->loadInstruction = _ARMLoadInstructionARM;
18		break;
19	case MODE_THUMB:
20		cpu->cpsr.t = 1;
21		cpu->instructionWidth = WORD_SIZE_THUMB;
22		cpu->loadInstruction = _ARMLoadInstructionThumb;
23	}
24}
25
26static ARMInstruction _ARMLoadInstructionARM(struct ARMMemory* memory, uint32_t address) {
27	int32_t opcode = memory->load32(memory, address);
28	return 0;
29}
30
31static ARMInstruction _ARMLoadInstructionThumb(struct ARMMemory* memory, uint32_t address) {
32	uint16_t opcode = memory->loadU16(memory, address);
33	return 0;
34}
35
36void ARMInit(struct ARMCore* cpu) {
37	int i;
38	for (i = 0; i < 16; ++i) {
39		cpu->gprs[i] = 0;
40	}
41
42	cpu->cpsr.packed = 0;
43	cpu->spsr.packed = 0;
44
45	cpu->cyclesToEvent = 0;
46
47	cpu->shifterOperand = 0;
48	cpu->shifterCarryOut = 0;
49
50	cpu->memory = 0;
51	cpu->board = 0;
52
53	cpu->executionMode = MODE_THUMB;
54	_ARMSetMode(cpu, MODE_ARM);
55}
56
57void ARMAssociateMemory(struct ARMCore* cpu, struct ARMMemory* memory) {
58	cpu->memory = memory;
59}
60
61void ARMCycle(struct ARMCore* cpu) {
62	// TODO
63	ARMInstruction instruction = cpu->loadInstruction(cpu->memory, cpu->gprs[ARM_PC] - cpu->instructionWidth);
64}