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DS Memory: Redzone rollover for WRAM, fixing some ARM7 variations

This commit is contained in:
Vicki Pfau 2017-02-22 18:58:40 -08:00
parent 3341cc3865
commit fc74ad9ceb
3 changed files with 46 additions and 10 deletions
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3
include/mgba/internal/ds/memory.h
View File

@ -18,6 +18,8 @@ CXX_GUARD_START
#include <mgba/internal/ds/slot1.h>
#include <mgba/internal/ds/spi.h>
const uint32_t redzoneInstruction;
enum DSMemoryRegion {
DS7_REGION_BIOS = 0x0,
DS9_REGION_ITCM = 0x0,
@ -80,6 +82,7 @@ struct DSMemory {
uint32_t* dtcm;
uint32_t* ram;
uint32_t* wram;
uint32_t* wramBase;
uint32_t* wramBase7;
uint32_t* wramBase9;
uint32_t* wram7;

11
src/ds/ds.c
View File

@ -553,7 +553,16 @@ void DSHitStub(struct ARMCore* cpu, uint32_t opcode) {
void DSIllegal(struct ARMCore* cpu, uint32_t opcode) {
struct DS* ds = (struct DS*) cpu->master;
if (ds->debugger) {
if ((opcode & 0xFFFF) == (redzoneInstruction & 0xFFFF)) {
int currentCycles = 0;
if (cpu->executionMode == MODE_THUMB) {
cpu->gprs[ARM_PC] -= WORD_SIZE_THUMB * 2;
THUMB_WRITE_PC;
} else {
cpu->gprs[ARM_PC] -= WORD_SIZE_ARM * 2;
ARM_WRITE_PC;
}
} else if (ds->debugger) {
struct mDebuggerEntryInfo info = {
.address = _ARMPCAddress(cpu),
.opcode = opcode

42
src/ds/memory.c
View File

@ -15,6 +15,7 @@
mLOG_DEFINE_CATEGORY(DS_MEM, "DS Memory");
static uint32_t _deadbeef[1] = { 0xE710B710 }; // Illegal instruction on both ARM and Thumb
const uint32_t redzoneInstruction = 0xE7F0DEF0;
static const uint32_t _vramMask[9] = {
0x1FFFF,
@ -102,7 +103,7 @@ void DSMemoryInit(struct DS* ds) {
ds->memory.bios7 = NULL;
ds->memory.bios9 = NULL;
ds->memory.wram = NULL;
ds->memory.wramBase = NULL;
ds->memory.wram7 = NULL;
ds->memory.ram = NULL;
ds->memory.itcm = NULL;
@ -141,9 +142,25 @@ void DSMemoryDeinit(struct DS* ds) {
void DSMemoryReset(struct DS* ds) {
if (ds->memory.wram) {
mappedMemoryFree(ds->memory.wram, DS_SIZE_WORKING_RAM);
mappedMemoryFree(ds->memory.wramBase, DS_SIZE_WORKING_RAM * 2 + 12);
}
ds->memory.wram = anonymousMemoryMap(DS_SIZE_WORKING_RAM);
// XXX: This hack lets you roll over the end of the WRAM block without
// looping back to the beginning. It works by placing an undefined
// instruction in a redzone at the very beginning and end of the buffer.
// Using clever masking tricks, the ARM loop will mask the offset so that
// either the middle of the passed-in buffer is the actual buffer, and
// when the loop rolls over, it hits the redzone at the beginning, or the
// start of the passed-in buffer matches the actual buffer, causing the
// redzone at the end to be hit. This requires a lot of dead space in
// the middle, and a fake (too large) mask, but it is very fast.
ds->memory.wram = anonymousMemoryMap(DS_SIZE_WORKING_RAM * 2 + 12);
ds->memory.wram[0] = redzoneInstruction;
ds->memory.wram[1] = redzoneInstruction;
ds->memory.wram[2] = redzoneInstruction;
ds->memory.wram[DS_SIZE_WORKING_RAM >> 1] = redzoneInstruction;
ds->memory.wram[(DS_SIZE_WORKING_RAM >> 1) + 1] = redzoneInstruction;
ds->memory.wram[(DS_SIZE_WORKING_RAM >> 1) + 2] = redzoneInstruction;
ds->memory.wramBase = &ds->memory.wram[DS_SIZE_WORKING_RAM >> 2];
if (ds->memory.wram7) {
mappedMemoryFree(ds->memory.wram7, DS7_SIZE_WORKING_RAM);
@ -212,9 +229,16 @@ static void DS7SetActiveRegion(struct ARMCore* cpu, uint32_t address) {
if (address >= DS7_BASE_WORKING_RAM || !ds->memory.wramSize7) {
cpu->memory.activeRegion = ds->memory.wram7;
cpu->memory.activeMask = DS7_SIZE_WORKING_RAM - 1;
} else if (ds->memory.wramSize7 == DS_SIZE_WORKING_RAM) {
if (address & DS_SIZE_WORKING_RAM) {
cpu->memory.activeRegion = ds->memory.wram;
} else {
cpu->memory.activeRegion = ds->memory.wramBase;
}
cpu->memory.activeMask = (ds->memory.wramSize7 << 1) - 1;
} else {
cpu->memory.activeRegion = ds->memory.wram;
cpu->memory.activeMask = ds->memory.wramSize7 - 1;
cpu->memory.activeRegion = ds->memory.wramBase;
cpu->memory.activeMask = (ds->memory.wramSize7 - 1);
}
break;
case DS7_REGION_BIOS:
@ -1288,23 +1312,23 @@ void DSConfigureWRAM(struct DSMemory* memory, uint8_t config) {
memory->wramSize7 = 0;
memory->wramBase7 = NULL;
memory->wramSize9 = DS_SIZE_WORKING_RAM;
memory->wramBase9 = memory->wram;
memory->wramBase9 = memory->wramBase;
break;
case 1:
memory->wramSize7 = DS_SIZE_WORKING_RAM >> 1;
memory->wramBase7 = memory->wram;
memory->wramSize9 = DS_SIZE_WORKING_RAM >> 1;
memory->wramBase9 = &memory->wram[DS_SIZE_WORKING_RAM >> 3];
memory->wramBase9 = &memory->wramBase[DS_SIZE_WORKING_RAM >> 3];
break;
case 2:
memory->wramSize7 = DS_SIZE_WORKING_RAM >> 1;
memory->wramBase7 = &memory->wram[DS_SIZE_WORKING_RAM >> 3];
memory->wramSize9 = DS_SIZE_WORKING_RAM >> 1;
memory->wramBase9 = memory->wram;
memory->wramBase9 = memory->wramBase;
break;
case 3:
memory->wramSize7 = DS_SIZE_WORKING_RAM;
memory->wramBase7 = memory->wram;
memory->wramBase7 = memory->wramBase;
memory->wramSize9 = 0;
memory->wramBase9 = NULL;
break;