From f187fba4fbee89d8fab91b445ed43d4ed0c0bc45 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Mon, 24 Jul 2017 13:48:59 -0700
Subject: [PATCH] GB MBC: More detailed TAMA5 implementation, working saves
---
include/mgba/internal/gb/memory.h | 14 ++++--
src/gb/mbc.c | 78 ++++++++++++++++++++++---------
2 files changed, 66 insertions(+), 26 deletions(-)
diff --git a/include/mgba/internal/gb/memory.h b/include/mgba/internal/gb/memory.h
index c2d5e92fa..44eb2a541 100644
--- a/include/mgba/internal/gb/memory.h
+++ b/include/mgba/internal/gb/memory.h
@@ -87,8 +87,16 @@ enum GBMBC7MachineState {
};
enum GBTAMA5Register {
- GBTAMA5_BANK = 0x0,
- GBTAMA5_MAX
+ GBTAMA5_BANK_LO = 0x0,
+ GBTAMA5_BANK_HI = 0x1,
+ GBTAMA5_WRITE_LO = 0x4,
+ GBTAMA5_WRITE_HI = 0x5,
+ GBTAMA5_CS = 0x6,
+ GBTAMA5_ADDR_LO = 0x7,
+ GBTAMA5_MAX = 0x8,
+ GBTAMA5_ACTIVE = 0xA,
+ GBTAMA5_READ_LO = 0xC,
+ GBTAMA5_READ_HI = 0xD,
};
struct GBMBC1State {
@@ -112,9 +120,7 @@ struct GBPocketCamState {
};
struct GBTAMA5State {
- bool unlocked;
uint8_t reg;
- uint8_t value;
uint8_t registers[GBTAMA5_MAX];
};
diff --git a/src/gb/mbc.c b/src/gb/mbc.c
index 9b628c322..496289a06 100644
--- a/src/gb/mbc.c
+++ b/src/gb/mbc.c
@@ -224,6 +224,7 @@ void GBMBCInit(struct GB* gb) {
memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
gb->memory.mbcWrite = _GBTAMA5;
gb->memory.mbcRead = _GBTAMA5Read;
+ gb->sramSize = 0x20;
break;
case GB_MBC3_RTC:
memset(gb->memory.rtcRegs, 0, sizeof(gb->memory.rtcRegs));
@@ -772,31 +773,39 @@ void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value) {
switch (address >> 13) {
case 0x5:
if (address & 1) {
- if (tama5->unlocked) {
- tama5->reg = value;
- } else if (value == 0xA) {
- tama5->unlocked = true;
- }
+ tama5->reg = value;
} else {
- uint8_t reg = tama5->reg >> 1;
- if (reg < GBTAMA5_MAX) {
- uint8_t mask = 0xF << (4 * (tama5->reg & 1));
- value <<= (4 * (tama5->reg & 1));
- value |= tama5->registers[reg] & ~mask;
- tama5->registers[reg] = value;
- if (tama5->reg & 1) {
- switch (reg) {
- case GBTAMA5_BANK:
- GBMBCSwitchBank(gb, value & 0x1F);
- // Fall through
- default:
- mLOG(GB_MBC, STUB, "TAMA5 unknown register: %02X:%02X", reg, value);
+ value &= 0xF;
+ if (tama5->reg < GBTAMA5_MAX) {
+ tama5->registers[tama5->reg] = value;
+ uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
+ uint8_t out = (tama5->registers[GBTAMA5_WRITE_HI] << 4) | tama5->registers[GBTAMA5_WRITE_LO];
+ switch (tama5->reg) {
+ case GBTAMA5_BANK_LO:
+ case GBTAMA5_BANK_HI:
+ GBMBCSwitchBank(gb, tama5->registers[GBTAMA5_BANK_LO] | (tama5->registers[GBTAMA5_BANK_HI] << 4));
+ break;
+ case GBTAMA5_WRITE_LO:
+ case GBTAMA5_WRITE_HI:
+ case GBTAMA5_CS:
+ break;
+ case GBTAMA5_ADDR_LO:
+ switch (tama5->registers[GBTAMA5_CS] >> 1) {
+ case 0x0: // RAM write
+ memory->sram[address] = out;
break;
+ case 0x1: // RAM read
+ break;
+ default:
+ mLOG(GB_MBC, STUB, "TAMA5 unknown address: %X-%02X:%02X", tama5->registers[GBTAMA5_CS] >> 1, address, out);
}
- tama5->unlocked = false;
+ break;
+ default:
+ mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X:%X", tama5->reg, value);
+ break;
}
} else {
- mLOG(GB_MBC, STUB, "TAMA5 unknown register: %02X", reg);
+ mLOG(GB_MBC, STUB, "TAMA5 unknown write: %02X", tama5->reg);
}
}
break;
@@ -807,11 +816,36 @@ void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value) {
uint8_t _GBTAMA5Read(struct GBMemory* memory, uint16_t address) {
struct GBTAMA5State* tama5 = &memory->mbcState.tama5;
- mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X", address);
+ if ((address & 0x1FFF) > 1) {
+ mLOG(GB_MBC, STUB, "TAMA5 unknown address: %04X", address);
+ }
if (address & 1) {
return 0xFF;
} else {
- return 0xF0 | tama5->unlocked;
+ uint8_t value = 0xF0;
+ uint8_t address = ((tama5->registers[GBTAMA5_CS] << 4) & 0x10) | tama5->registers[GBTAMA5_ADDR_LO];
+ switch (tama5->reg) {
+ case GBTAMA5_ACTIVE:
+ return 0xF1;
+ case GBTAMA5_READ_LO:
+ case GBTAMA5_READ_HI:
+ switch (tama5->registers[GBTAMA5_CS] >> 1) {
+ case 1:
+ value = memory->sram[address];
+ break;
+ default:
+ mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
+ break;
+ }
+ if (tama5->reg == GBTAMA5_READ_HI) {
+ value >>= 4;
+ }
+ value |= 0xF0;
+ return value;
+ default:
+ mLOG(GB_MBC, STUB, "TAMA5 unknown read: %02X", tama5->reg);
+ return 0xF1;
+ }
}
}