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|
#include "rockmacros.h"
#include "defs.h"
#include "hw.h"
#include "regs.h"
#include "mem.h"
#include "rtc-gb.h"
#include "lcd-gb.h"
#include "lcdc.h"
#include "sound.h"
struct mbc mbc IBSS_ATTR;
struct rom rom IBSS_ATTR;
struct ram ram;
/*
* In order to make reads and writes efficient, we keep tables
* (indexed by the high nibble of the address) specifying which
* regions can be read/written without a function call. For such
* ranges, the pointer in the map table points to the base of the
* region in host system memory. For ranges that require special
* processing, the pointer is NULL.
*
* mem_updatemap is called whenever bank changes or other operations
* make the old maps potentially invalid.
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Warray-bounds"
void mem_updatemap(void)
{
int n;
static byte **map;
map = mbc.rmap;
map[0x0] = rom.bank[0];
map[0x1] = rom.bank[0];
map[0x2] = rom.bank[0];
map[0x3] = rom.bank[0];
if (mbc.rombank < mbc.romsize)
{
map[0x4] = rom.bank[mbc.rombank] - 0x4000;
map[0x5] = rom.bank[mbc.rombank] - 0x4000;
map[0x6] = rom.bank[mbc.rombank] - 0x4000;
map[0x7] = rom.bank[mbc.rombank] - 0x4000;
}
else map[0x4] = map[0x5] = map[0x6] = map[0x7] = NULL;
if (0 && (R_STAT & 0x03) == 0x03)
{
map[0x8] = NULL;
map[0x9] = NULL;
}
else
{
map[0x8] = lcd.vbank[R_VBK & 1] - 0x8000;
map[0x9] = lcd.vbank[R_VBK & 1] - 0x8000;
}
if (mbc.enableram && !(rtc.sel&8))
{
map[0xA] = ram.sbank[mbc.rambank] - 0xA000;
map[0xB] = ram.sbank[mbc.rambank] - 0xA000;
}
else map[0xA] = map[0xB] = NULL;
map[0xC] = ram.ibank[0] - 0xC000; // XXX
n = R_SVBK & 0x07;
map[0xD] = ram.ibank[n?n:1] - 0xD000;
map[0xE] = ram.ibank[0] - 0xE000; // XXX
map[0xF] = NULL;
map = mbc.wmap;
map[0x0] = map[0x1] = map[0x2] = map[0x3] = NULL;
map[0x4] = map[0x5] = map[0x6] = map[0x7] = NULL;
map[0x8] = map[0x9] = NULL;
if (mbc.enableram && !(rtc.sel&8))
{
map[0xA] = ram.sbank[mbc.rambank] - 0xA000;
map[0xB] = ram.sbank[mbc.rambank] - 0xA000;
}
else map[0xA] = map[0xB] = NULL;
map[0xC] = ram.ibank[0] - 0xC000; // XXX
n = R_SVBK & 0x07;
map[0xD] = ram.ibank[n?n:1] - 0xD000;
map[0xE] = ram.ibank[0] - 0xE000; // XXX
map[0xF] = NULL;
}
#pragma GCC diagnostic pop
/*
* ioreg_write handles output to io registers in the FF00-FF7F,FFFF
* range. It takes the register number (low byte of the address) and a
* byte value to be written.
*/
static void ioreg_write(byte r, byte b) ICODE_ATTR;
static void ioreg_write(byte r, byte b)
{
if (!hw.cgb)
{
switch (r)
{
case RI_VBK:
case RI_BCPS:
case RI_OCPS:
case RI_BCPD:
case RI_OCPD:
case RI_SVBK:
case RI_KEY1:
case RI_HDMA1:
case RI_HDMA2:
case RI_HDMA3:
case RI_HDMA4:
case RI_HDMA5:
return;
}
}
switch(r)
{
case RI_TIMA:
case RI_TMA:
case RI_TAC:
case RI_SCY:
case RI_SCX:
case RI_WY:
case RI_WX:
REG(r) = b;
break;
case RI_BGP:
if (R_BGP == b) break;
pal_write_dmg(0, 0, b);
pal_write_dmg(8, 1, b);
R_BGP = b;
break;
case RI_OBP0:
if (R_OBP0 == b) break;
pal_write_dmg(64, 2, b);
R_OBP0 = b;
break;
case RI_OBP1:
if (R_OBP1 == b) break;
pal_write_dmg(72, 3, b);
R_OBP1 = b;
break;
case RI_IF:
case RI_IE:
REG(r) = b & 0x1F;
break;
case RI_P1:
REG(r) = b;
pad_refresh();
break;
case RI_SC:
/* FIXME - this is a hack for stupid roms that probe serial */
if ((b & 0x81) == 0x81)
{
R_SB = 0xff;
hw_interrupt(IF_SERIAL, IF_SERIAL);
hw_interrupt(0, IF_SERIAL);
}
R_SC = b; /* & 0x7f; */
break;
case RI_DIV:
REG(r) = 0;
break;
case RI_LCDC:
lcdc_change(b);
break;
case RI_STAT:
REG(r) = (REG(r) & 0x07) | (b & 0x78);
stat_trigger();
break;
case RI_LYC:
REG(r) = b;
stat_trigger();
break;
case RI_VBK:
REG(r) = b | 0xFE;
mem_updatemap();
break;
case RI_BCPS:
R_BCPS = b & 0xBF;
R_BCPD = lcd.pal[b & 0x3F];
break;
case RI_OCPS:
R_OCPS = b & 0xBF;
R_OCPD = lcd.pal[64 + (b & 0x3F)];
break;
case RI_BCPD:
R_BCPD = b;
pal_write(R_BCPS & 0x3F, b);
if (R_BCPS & 0x80) R_BCPS = (R_BCPS+1) & 0xBF;
break;
case RI_OCPD:
R_OCPD = b;
pal_write(64 + (R_OCPS & 0x3F), b);
if (R_OCPS & 0x80) R_OCPS = (R_OCPS+1) & 0xBF;
break;
case RI_SVBK:
REG(r) = b & 0x07;
mem_updatemap();
break;
case RI_DMA:
hw_dma(b);
break;
case RI_KEY1:
REG(r) = (REG(r) & 0x80) | (b & 0x01);
break;
case RI_HDMA1:
REG(r) = b;
break;
case RI_HDMA2:
REG(r) = b & 0xF0;
break;
case RI_HDMA3:
REG(r) = b & 0x1F;
break;
case RI_HDMA4:
REG(r) = b & 0xF0;
break;
case RI_HDMA5:
hw_hdma_cmd(b);
break;
}
}
static byte ioreg_read(byte r)
{
switch(r)
{
case RI_SC:
r = R_SC;
R_SC &= 0x7f;
return r;
case RI_P1:
case RI_SB:
case RI_DIV:
case RI_TIMA:
case RI_TMA:
case RI_TAC:
case RI_LCDC:
case RI_STAT:
case RI_SCY:
case RI_SCX:
case RI_LY:
case RI_LYC:
case RI_BGP:
case RI_OBP0:
case RI_OBP1:
case RI_WY:
case RI_WX:
case RI_IE:
case RI_IF:
return REG(r);
case RI_VBK:
case RI_BCPS:
case RI_OCPS:
case RI_BCPD:
case RI_OCPD:
case RI_SVBK:
case RI_KEY1:
case RI_HDMA1:
case RI_HDMA2:
case RI_HDMA3:
case RI_HDMA4:
case RI_HDMA5:
if (hw.cgb) return REG(r);
default:
return 0xff;
}
}
/*
* Memory bank controllers typically intercept write attempts to
* 0000-7FFF, using the address and byte written as instructions to
* change rom or sram banks, control special hardware, etc.
*
* mbc_write takes an address (which should be in the proper range)
* and a byte value written to the address.
*/
static void mbc_write(int a, byte b) ICODE_ATTR;
static void mbc_write(int a, byte b)
{
byte ha = (a>>12);
/* printf("mbc %d: rom bank %02X -[%04X:%02X]-> ", mbc.type, mbc.rombank, a, b); */
switch (mbc.type)
{
case MBC_MBC1:
switch (ha & 0xE)
{
case 0x0:
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
case 0x2:
if ((b & 0x1F) == 0) b = 0x01;
mbc.rombank = (mbc.rombank & 0x60) | (b & 0x1F);
break;
case 0x4:
if (mbc.model)
{
mbc.rambank = b & 0x03;
break;
}
mbc.rombank = (mbc.rombank & 0x1F) | ((int)(b&3)<<5);
break;
case 0x6:
mbc.model = b & 0x1;
break;
}
break;
case MBC_MBC2: /* is this at all right? */
if ((a & 0x0100) == 0x0000)
{
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
}
if ((a & 0xE100) == 0x2100)
{
mbc.rombank = b & 0x0F;
break;
}
break;
case MBC_MBC3:
switch (ha & 0xE)
{
case 0x0:
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
case 0x2:
if ((b & 0x7F) == 0) b = 0x01;
mbc.rombank = b & 0x7F;
break;
case 0x4:
rtc.sel = b & 0x0f;
mbc.rambank = b & 0x03;
break;
case 0x6:
rtc_latch(b);
break;
}
break;
case MBC_RUMBLE:
switch (ha & 0xF)
{
case 0x4:
case 0x5:
/* FIXME - save high bit as rumble state */
/* mask off high bit */
b &= 0x7;
break;
}
/* fall thru */
case MBC_MBC5:
switch (ha & 0xF)
{
case 0x0:
case 0x1:
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
case 0x2:
if ((b & 0xFF) == 0) b = 0x01;
mbc.rombank = (mbc.rombank & 0x100) | (b & 0xFF);
break;
case 0x3:
mbc.rombank = (mbc.rombank & 0xFF) | ((int)(b&1)<<8);
break;
case 0x4:
case 0x5:
mbc.rambank = b & 0x0f;
break;
}
break;
case MBC_HUC1: /* FIXME - this is all guesswork -- is it right??? */
switch (ha & 0xE)
{
case 0x0:
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
case 0x2:
if ((b & 0x1F) == 0) b = 0x01;
mbc.rombank = (mbc.rombank & 0x60) | (b & 0x1F);
break;
case 0x4:
if (mbc.model)
{
mbc.rambank = b & 0x03;
break;
}
mbc.rombank = (mbc.rombank & 0x1F) | ((int)(b&3)<<5);
break;
case 0x6:
mbc.model = b & 0x1;
break;
}
break;
case MBC_HUC3: /* FIXME - this is all guesswork -- is it right??? */
switch (ha & 0xE)
{
case 0x0:
mbc.enableram = ((b & 0x0F) == 0x0A);
break;
case 0x2:
if (!b) b = 1;
mbc.rombank = b;
break;
case 0x4:
if (mbc.model)
{
mbc.rambank = b & 0x03;
break;
}
break;
case 0x6:
mbc.model = b & 1;
break;
}
break;
}
mbc.rombank &= (mbc.romsize - 1);
mbc.rambank &= (mbc.ramsize - 1);
mem_updatemap();
}
/*
* mem_write is the basic write function. Although it should only be
* called when the write map contains a NULL for the requested address
* region, it accepts writes to any address.
*/
void mem_write(int a, byte b)
{
int n;
byte ha = (a>>12) & 0xE;
/* printf("write to 0x%04X: 0x%02X\n", a, b); */
switch (ha)
{
case 0x0:
case 0x2:
case 0x4:
case 0x6:
mbc_write(a, b);
break;
case 0x8:
/* if ((R_STAT & 0x03) == 0x03) break; */
vram_write(a & 0x1FFF, b);
break;
case 0xA:
if (!mbc.enableram) break;
if (rtc.sel&8)
{
rtc_write(b);
break;
}
ram.sbank[mbc.rambank][a & 0x1FFF] = b;
break;
case 0xC:
if ((a & 0xF000) == 0xC000)
{
ram.ibank[0][a & 0x0FFF] = b;
break;
}
n = R_SVBK & 0x07;
ram.ibank[n?n:1][a & 0x0FFF] = b;
break;
case 0xE:
if (a < 0xFE00)
{
mem_write(a & 0xDFFF, b);
break;
}
if ((a & 0xFF00) == 0xFE00)
{
/* if (R_STAT & 0x02) break; */
if (a < 0xFEA0) lcd.oam.mem[a & 0xFF] = b;
break;
}
/* return writehi(a & 0xFF, b); */
if (a >= 0xFF10 && a <= 0xFF3F)
{
if(options.sound)
sound_write(a & 0xFF, b);
break;
}
if ((a & 0xFF80) == 0xFF80 && a != 0xFFFF)
{
ram.hi[a & 0xFF] = b;
break;
}
ioreg_write(a & 0xFF, b);
}
}
/*
* mem_read is the basic read function...not useful for much anymore
* with the read map, but it's still necessary for the final messy
* region.
*/
byte mem_read(int a)
{
int n;
byte ha = (a>>12) & 0xE;
/* printf("read %04x\n", a); */
switch (ha)
{
case 0x0:
case 0x2:
return rom.bank[0][a];
case 0x4:
case 0x6:
return rom.bank[mbc.rombank][a & 0x3FFF];
case 0x8:
/* if ((R_STAT & 0x03) == 0x03) return 0xFF; */
return lcd.vbank[R_VBK&1][a & 0x1FFF];
case 0xA:
if (!mbc.enableram)
return 0xFF;
if (rtc.sel&8)
return rtc.regs[rtc.sel&7];
return ram.sbank[mbc.rambank][a & 0x1FFF];
case 0xC:
if ((a & 0xF000) == 0xC000)
return ram.ibank[0][a & 0x0FFF];
n = R_SVBK & 0x07;
return ram.ibank[n?n:1][a & 0x0FFF];
case 0xE:
if (a < 0xFE00) return mem_read(a & 0xDFFF);
if ((a & 0xFF00) == 0xFE00)
{
/* if (R_STAT & 0x02) return 0xFF; */
if (a < 0xFEA0) return lcd.oam.mem[a & 0xFF];
return 0xFF;
}
/* return readhi(a & 0xFF); */
if (a == 0xFFFF) return REG(0xFF);
if (a >= 0xFF10 && a <= 0xFF3F)
{
if(options.sound)
return sound_read(a & 0xFF);
else
return 1;
}
if ((a & 0xFF80) == 0xFF80)
return ram.hi[a & 0xFF];
return ioreg_read(a & 0xFF);
}
return 0xff; /* not reached */
}
void mbc_reset(void)
{
mbc.rombank = 1;
mbc.rambank = 0;
mbc.enableram = 0;
mem_updatemap();
}
|
