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sms, improve ROM bank mapping, add some SRAM support

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This commit is contained in:
kub 2021-10-03 23:59:09 +02:00
parent 15caa286fc
commit b784d4a5f7
4 changed files with 69 additions and 11 deletions
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16
pico/cart.c
View file

@ -34,6 +34,7 @@ void (*PicoCDLoadProgressCB)(const char *fname, int percent) = NULL; // handled
int PicoGameLoaded;
static void PicoCartDetect(const char *carthw_cfg);
static void PicoCartDetectMS(void);
/* cso struct */
typedef struct _cso_struct
@ -850,6 +851,8 @@ int PicoCartInsert(unsigned char *rom, unsigned int romsize, const char *carthw_
if (!(PicoIn.AHW & (PAHW_MCD|PAHW_SMS)))
PicoCartDetect(carthw_cfg);
else if (PicoIn.AHW & PAHW_SMS)
PicoCartDetectMS();
// setup correct memory map for loaded ROM
switch (PicoIn.AHW) {
@ -1320,4 +1323,17 @@ static void PicoCartDetect(const char *carthw_cfg)
*(u32 *) (Pico.rom + 0x1f0) = CPU_LE4(0x20204520);
}
static void PicoCartDetectMS(void)
{
memset(&Pico.sv, 0, sizeof(Pico.sv));
// Always map SRAM, since there's no indicator in ROM if it's needed or not
// TODO: this should somehow be coming from a cart database!
Pico.sv.size = 0x8000; // Sega mapper, 2 banks of 16 KB each
Pico.sv.flags |= SRF_ENABLED;
Pico.sv.data = calloc(Pico.sv.size, 1);
if (Pico.sv.data == NULL)
Pico.sv.flags &= ~SRF_ENABLED;
}
// vim:shiftwidth=2:expandtab

2
pico/memory.h
View file

@ -38,7 +38,7 @@ extern void s68k_write16(u32 a, u16 d);
extern void s68k_write32(u32 a, u32 d);
// z80
#define Z80_MEM_SHIFT 13
#define Z80_MEM_SHIFT 10 // must be <=10 to allow 1KB pages for SMS Sega mapper
extern uptr z80_read_map [0x10000 >> Z80_MEM_SHIFT];
extern uptr z80_write_map[0x10000 >> Z80_MEM_SHIFT];
typedef unsigned char (z80_read_f)(unsigned short a);

59
pico/sms.c
View file

@ -219,17 +219,30 @@ static void z80_sms_out(unsigned short a, unsigned char d)
static int bank_mask;
static void xwrite(unsigned int a, unsigned char d);
static void write_sram(unsigned short a, unsigned char d)
{
// SRAM is mapped in 2 16KB banks, selected by bit 2 in control reg
a &= 0x3fff;
a += ((Pico.ms.carthw[0x0c] & 0x04) >> 2) * 0x4000;
Pico.sv.changed |= (Pico.sv.data[a] != d);
Pico.sv.data[a] = d;
}
static void write_bank(unsigned short a, unsigned char d)
{
elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
Pico.ms.carthw[a & 0x0f] = d;
switch (a & 0x0f)
{
case 0x0c:
elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d);
break;
case 0x0d:
if (d != 0)
elprintf(EL_STATUS|EL_ANOMALY, "bank0 changed to %d!", d);
d &= bank_mask;
z80_map_set(z80_read_map, 0x0400, 0x3fff, Pico.rom+0x400 + (d << 14), 0);
#ifdef _USE_CZ80
Cz80_Set_Fetch(&CZ80, 0x0400, 0x3fff, (FPTR)Pico.rom+0x400 + (d << 14));
#endif
break;
case 0x0e:
d &= bank_mask;
@ -238,15 +251,29 @@ static void write_bank(unsigned short a, unsigned char d)
Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
#endif
break;
case 0x0c:
if (d & ~0x8c)
elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d);
/*FALLTHROUGH*/
case 0x0f:
d &= bank_mask;
z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
if (Pico.ms.carthw[0xc] & 0x08) {
d = (Pico.ms.carthw[0xc] & 0x04) >> 2;
z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.sv.data + d*0x4000, 0);
#ifdef _USE_CZ80
Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.sv.data + d*0x4000);
#endif
z80_map_set(z80_write_map, 0x8000, 0xbfff, write_sram, 1);
} else {
d = Pico.ms.carthw[0xf] & bank_mask;
z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
#ifdef _USE_CZ80
Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
#endif
z80_map_set(z80_write_map, 0x8000, 0xbfff, xwrite, 1);
}
break;
}
Pico.ms.carthw[a & 0x0f] = d;
}
static void xwrite(unsigned int a, unsigned char d)
@ -256,6 +283,16 @@ static void xwrite(unsigned int a, unsigned char d)
PicoMem.zram[a & 0x1fff] = d;
if (a >= 0xfff8)
write_bank(a, d);
// codemasters
if (a == 0x0000)
write_bank(0xfffd, d);
if (a == 0x4000)
write_bank(0xfffe, d);
if (a == 0x8000)
write_bank(0xffff, d);
// korean
if (a == 0xa000)
write_bank(0xffff, d);
}
void PicoResetMS(void)
@ -284,6 +321,8 @@ void PicoPowerMS(void)
tmp = 1 << s;
bank_mask = (tmp - 1) >> 14;
Pico.ms.carthw[0x0c] = 0;
Pico.ms.carthw[0x0d] = 0;
Pico.ms.carthw[0x0e] = 1;
Pico.ms.carthw[0x0f] = 2;
@ -315,6 +354,8 @@ void PicoMemSetupMS(void)
void PicoStateLoadedMS(void)
{
write_bank(0xfffc, Pico.ms.carthw[0x0c]);
write_bank(0xfffd, Pico.ms.carthw[0x0d]);
write_bank(0xfffe, Pico.ms.carthw[0x0e]);
write_bank(0xffff, Pico.ms.carthw[0x0f]);
}