1#include "gba.h"
  2
  3#include "gba-bios.h"
  4#include "gba-io.h"
  5
  6#include "debugger.h"
  7
  8#include <limits.h>
  9#include <stdarg.h>
 10#include <stdio.h>
 11#include <stdlib.h>
 12#include <sys/mman.h>
 13
 14enum {
 15	SP_BASE_SYSTEM = 0x03FFFF00,
 16	SP_BASE_IRQ = 0x03FFFFA0,
 17	SP_BASE_SUPERVISOR = 0x03FFFFE0
 18};
 19
 20static void GBAProcessEvents(struct ARMBoard* board);
 21static void GBAHitStub(struct ARMBoard* board, uint32_t opcode);
 22
 23void GBAInit(struct GBA* gba) {
 24	gba->errno = GBA_NO_ERROR;
 25	gba->errstr = 0;
 26
 27	ARMInit(&gba->cpu);
 28
 29	gba->memory.p = gba;
 30	GBAMemoryInit(&gba->memory);
 31	ARMAssociateMemory(&gba->cpu, &gba->memory.d);
 32
 33	gba->board.p = gba;
 34	GBABoardInit(&gba->board);
 35	ARMAssociateBoard(&gba->cpu, &gba->board.d);
 36
 37	gba->video.p = gba;
 38	GBAVideoInit(&gba->video);
 39
 40	ARMReset(&gba->cpu);
 41}
 42
 43void GBADeinit(struct GBA* gba) {
 44	GBAMemoryDeinit(&gba->memory);
 45}
 46
 47void GBABoardInit(struct GBABoard* board) {
 48	board->d.reset = GBABoardReset;
 49	board->d.processEvents = GBAProcessEvents;
 50	board->d.swi16 = GBASwi16;
 51	board->d.swi32 = GBASwi32;
 52	board->d.hitStub = GBAHitStub;
 53}
 54
 55void GBABoardReset(struct ARMBoard* board) {
 56	struct ARMCore* cpu = board->cpu;
 57	ARMSetPrivilegeMode(cpu, MODE_IRQ);
 58	cpu->gprs[ARM_SP] = SP_BASE_IRQ;
 59	ARMSetPrivilegeMode(cpu, MODE_SUPERVISOR);
 60	cpu->gprs[ARM_SP] = SP_BASE_SUPERVISOR;
 61	ARMSetPrivilegeMode(cpu, MODE_SYSTEM);
 62	cpu->gprs[ARM_SP] = SP_BASE_SYSTEM;
 63}
 64
 65static void GBAProcessEvents(struct ARMBoard* board) {
 66	struct GBABoard* gbaBoard = (struct GBABoard*) board;
 67	int32_t cycles = board->cpu->cycles;
 68	int32_t nextEvent = INT_MAX;
 69	int32_t testEvent;
 70
 71	testEvent = GBAVideoProcessEvents(&gbaBoard->p->video, cycles);
 72	if (testEvent < nextEvent) {
 73		nextEvent = testEvent;
 74	}
 75
 76	board->cpu->cycles = 0;
 77	board->cpu->nextEvent = nextEvent;
 78}
 79
 80void GBAAttachDebugger(struct GBA* gba, struct ARMDebugger* debugger) {
 81	ARMDebuggerInit(debugger, &gba->cpu);
 82	gba->debugger = debugger;
 83}
 84
 85void GBALoadROM(struct GBA* gba, int fd) {
 86	gba->memory.rom = mmap(0, SIZE_CART0, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FILE, fd, 0);
 87	// TODO: error check
 88}
 89
 90void GBAWriteIE(struct GBA* gba, uint16_t value) {
 91	if (value & ((1 << IRQ_TIMER0) | (1 << IRQ_TIMER1) | (1 << IRQ_TIMER2) | (1 << IRQ_TIMER3))) {
 92		GBALog(GBA_LOG_STUB, "Timer interrupts not implemented");
 93	}
 94
 95	if (value & (1 << IRQ_SIO)) {
 96		GBALog(GBA_LOG_STUB, "SIO interrupts not implemented");
 97	}
 98
 99	if (value & ((1 << IRQ_DMA0) | (1 << IRQ_DMA1) | (1 << IRQ_DMA2) | (1 << IRQ_DMA3))) {
100		GBALog(GBA_LOG_STUB, "DMA interrupts not implemented");
101	}
102
103	if (value & (1 << IRQ_KEYPAD)) {
104		GBALog(GBA_LOG_STUB, "Keypad interrupts not implemented");
105	}
106
107	if (value & (1 << IRQ_GAMEPAK)) {
108		GBALog(GBA_LOG_STUB, "Gamepak interrupts not implemented");
109	}
110
111	if (gba->memory.io[REG_IME >> 1] && value & gba->memory.io[REG_IF >> 1]) {
112		ARMRaiseIRQ(&gba->cpu);
113	}
114}
115
116void GBAWriteIME(struct GBA* gba, uint16_t value) {
117	if (value && gba->memory.io[REG_IE >> 1] & gba->memory.io[REG_IF >> 1]) {
118		ARMRaiseIRQ(&gba->cpu);
119	}
120}
121
122void GBARaiseIRQ(struct GBA* gba, enum GBAIRQ irq) {
123	gba->memory.io[REG_IF >> 1] |= 1 << irq;
124
125	if (gba->memory.io[REG_IME >> 1] && (gba->memory.io[REG_IE >> 1] & 1 << irq)) {
126		ARMRaiseIRQ(&gba->cpu);
127	}
128}
129
130void GBALog(int level, const char* format, ...) {
131	va_list args;
132	va_start(args, format);
133	vprintf(format, args);
134	va_end(args);
135	printf("\n");
136}
137
138void GBAHitStub(struct ARMBoard* board, uint32_t opcode) {
139	GBALog(GBA_LOG_STUB, "Stub opcode: %08x", opcode);
140	struct GBABoard* gbaBoard = (struct GBABoard*) board;
141	if (!gbaBoard->p->debugger) {
142		abort();
143	} else {
144		ARMDebuggerEnter(gbaBoard->p->debugger);
145	}
146}