ShuriZma
/
snes9x
mirror of https://github.com/snes9xgit/snes9x.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

[BS-X] Memory Pack Type 1 emulation

This commit is contained in:
luigiblood 2016-11-08 14:56:32 +01:00
parent 115c513424
commit cf00193655
2 changed files with 144 additions and 95 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

192
bsx.cpp
View File

@ -222,7 +222,7 @@ static const uint8 flashcard[20] =
{
0x4D, 0x00, 0x50, 0x00, // vendor id
0x00, 0x00, // ?
0x2A, 0x00, // 2MB Flash (1MB = 0x2A)
0x1A, 0x00, // 2MB Flash (1MB = 0x2A)
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
@ -674,27 +674,17 @@ static void BSX_Map (void)
static uint8 BSX_Get_Bypass_FlashIO (uint16 offset)
{
if (BSX.MMC[0x02])
return (MapROM[offset]);
return (MapROM[offset & 0x0FFFFF]);
else
{
if (offset < 0x8000)
return (MapROM[offset]);
else
return (MapROM[offset - 0x8000]);
}
return (MapROM[(offset & 0x0F0000) >> 1 | (offset & 0x7FFF)]);
}
static void BSX_Set_Bypass_FlashIO (uint16 offset, uint8 byte)
{
if (BSX.MMC[0x02])
MapROM[offset] = byte;
MapROM[offset & 0x0FFFFF] = byte;
else
{
if (offset < 0x8000)
MapROM[offset] = byte;
else
MapROM[offset - 0x8000] = byte;
}
MapROM[(offset & 0x0F0000) >> 1 | (offset & 0x7FFF)] = byte;
}
uint8 S9xGetBSX (uint32 address)
@ -708,17 +698,24 @@ uint8 S9xGetBSX (uint32 address)
return (BSX.MMC[bank]);
// Flash IO
if (bank == 0xC0)
if (bank >= 0xC0)
{
// default: read-through mode
t = BSX_Get_Bypass_FlashIO(offset);
t = BSX_Get_Bypass_FlashIO(address);
// note: may be more registers, purposes unknown
switch (offset)
{
case 0x0002:
if (BSX.flash_enable)
t = 0x80; // status register?
case 0x8002:
if (BSX.flash_bsr)
t = 0xC0; // Page Status Register
break;
case 0x0004:
case 0x8004:
if (BSX.flash_gsr)
t = 0x82; // Global Status Register
break;
case 0x5555:
@ -741,6 +738,13 @@ uint8 S9xGetBSX (uint32 address)
t = flashcard[offset - 0xFF00];
break;
}
if (BSX.flash_csr)
{
t = 0x80; // Compatible Status Register
BSX.flash_csr = false;
}
}
return (t);
@ -760,75 +764,115 @@ void S9xSetBSX (uint8 byte, uint32 address)
}
// Flash IO
if (bank == 0xC0)
if (bank >= 0xC0)
{
BSX.old_write = BSX.new_write;
BSX.new_write = address;
// ???: double writes to the desired address will bypass
// flash registers
if (BSX.old_write == BSX.new_write && BSX.write_enable)
// Write to Flash
if (BSX.write_enable)
{
BSX_Set_Bypass_FlashIO(offset, byte);
BSX_Set_Bypass_FlashIO(address, byte);
//MapROM[address & 0x3FFFFF] = byte;
BSX.write_enable = false;
return;
}
// flash command handling
// note: incomplete
switch (offset)
{
case 0x0000:
// Flash Command Handling
if (BSX.MMC[0xC]) {
//Memory Pack Type 1 & 3 & 4
BSX.flash_command <<= 8;
BSX.flash_command |= byte;
if ((BSX.flash_command & 0xFFFF) == 0x38D0)
switch (BSX.flash_command & 0xFF)
{
// retrieve information about the flash card
BSX.flash_enable = TRUE;
BSX.read_enable = TRUE;
case 0x00:
case 0xFF:
//Reset to normal
BSX.flash_enable = false;
BSX.flash_bsr = false;
BSX.flash_csr = false;
BSX.flash_gsr = false;
BSX.read_enable = false;
BSX.write_enable = false;
BSX.flash_cmd_done = true;
break;
case 0x10:
case 0x40:
//Write Byte
BSX.flash_enable = false;
BSX.flash_bsr = false;
BSX.flash_csr = true;
BSX.flash_gsr = false;
BSX.read_enable = false;
BSX.write_enable = true;
BSX.flash_cmd_done = true;
break;
case 0x50:
//Clear Status Register
BSX.flash_enable = false;
BSX.flash_bsr = false;
BSX.flash_csr = false;
BSX.flash_gsr = false;
BSX.flash_cmd_done = true;
break;
case 0x70:
//Read CSR
BSX.flash_enable = false;
BSX.flash_bsr = false;
BSX.flash_csr = true;
BSX.flash_gsr = false;
BSX.read_enable = false;
BSX.write_enable = false;
BSX.flash_cmd_done = true;
break;
case 0x71:
//Read Extended Status Registers (Page and Global)
BSX.flash_enable = false;
BSX.flash_bsr = true;
BSX.flash_csr = false;
BSX.flash_gsr = true;
BSX.read_enable = false;
BSX.write_enable = false;
BSX.flash_cmd_done = true;
break;
case 0x75:
//Show Page Buffer / Vendor Info
BSX.flash_csr = false;
BSX.read_enable = true;
BSX.flash_cmd_done = true;
break;
case 0xD0:
//DO COMMAND
switch (BSX.flash_command & 0xFFFF)
{
case 0x20D0: //Block Erase
uint32 x;
for (x = 0; x < 0x10000; x++) {
BSX_Set_Bypass_FlashIO(((address & 0xFF0000) + x), 0xFF);
//MapROM[((address & 0xFF0000) - 0xC00000) + x] = 0xFF;
}
break;
case 0x2AAA:
BSX.flash_command <<= 8;
BSX.flash_command |= byte;
break;
case 0x5555:
BSX.flash_command <<= 8;
BSX.flash_command |= byte;
switch (BSX.flash_command & 0xFFFFFF)
case 0xA7D0: //Chip Erase (ONLY IN TYPE 1 AND 4)
if ((flashcard[6] & 0xF0) == 0x10 || (flashcard[6] & 0xF0) == 0x40)
{
case 0xAA55F0:
// turn off flash i/o
BSX.flash_enable = FALSE;
BSX.write_enable = FALSE;
BSX.read_enable = FALSE;
break;
case 0xAA55A0:
// enable writing to flash
BSX.old_write = 0;
BSX.new_write = 0;
BSX.flash_enable = TRUE;
BSX.write_enable = TRUE;
BSX_Map();
break;
case 0xAA5570:
// turn on write-protection
BSX.write_enable = FALSE;
BSX_Map();
break;
case 0xAA5580:
case 0xAA5510:
// ???
break;
uint32 x;
for (x = 0; x < FLASH_SIZE; x++) {
BSX_Set_Bypass_FlashIO(x, 0xFF);
//MapROM[x] = 0xFF;
}
}
break;
case 0x38D0: //Flashcart Reset
break;
}
break;
}
}
}
}

5
bsx.h
View File

@ -199,6 +199,11 @@ struct SBSX
uint8 MMC[16];
uint8 prevMMC[16];
uint8 test2192[32];
bool flash_csr;
bool flash_gsr;
bool flash_bsr;
bool flash_cmd_done;
};
extern struct SBSX BSX;