willem/Pico-GB
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Incorporate latest peanut_gb.h from deltabeard (3d5ee50)

Browse Source
This commit is contained in:
Vincent Mistler
2023-05-10 11:06:03 +02:00
parent 4fcf31bf53
commit 760e1b9b04
1 changed files with 49 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files
inc/peanut_gb.h
+49 -15
View File
@@ -549,7 +549,7 @@ struct gb_s
uint8_t cart_ram;
/* Number of ROM banks in cartridge. */
uint16_t num_rom_banks_mask;
/* Number of RAM banks in cartridge. */
/* Number of RAM banks in cartridge. Ignore for MBC2. */
uint8_t num_ram_banks;
uint16_t selected_rom_bank;
@@ -694,7 +694,7 @@ struct gb_s
* Internal function used to read bytes.
* addr is host platform endian.
*/
uint8_t __gb_read(struct gb_s *gb, const uint16_t addr)
uint8_t __gb_read(struct gb_s *gb, uint16_t addr)
{
switch(PEANUT_GB_GET_MSN16(addr))
{
@@ -732,6 +732,12 @@ uint8_t __gb_read(struct gb_s *gb, const uint16_t addr)
{
if(gb->mbc == 3 && gb->cart_ram_bank >= 0x08)
return gb->cart_rtc[gb->cart_ram_bank - 0x08];
else if(gb->mbc == 2)
{
/* Only 9 bits are available in address. */
addr &= 0x1FF;
return gb->gb_cart_ram_read(gb, addr);
}
else if((gb->cart_mode_select || gb->mbc != 1) &&
gb->cart_ram_bank < gb->num_ram_banks)
{
@@ -796,19 +802,20 @@ uint8_t __gb_read(struct gb_s *gb, const uint16_t addr)
/**
* Internal function used to write bytes.
*/
void __gb_write(struct gb_s *gb, const uint_fast16_t addr, const uint8_t val)
void __gb_write(struct gb_s *gb, uint_fast16_t addr, uint8_t val)
{
switch(PEANUT_GB_GET_MSN16(addr))
{
case 0x0:
case 0x1:
if(gb->mbc == 2 && addr & 0x10)
return;
else if(gb->mbc > 0 && gb->cart_ram)
/* Set RAM enable bit. MBC2 is handled in fall-through. */
if(gb->mbc > 0 && gb->mbc != 2 && gb->cart_ram)
{
gb->enable_cart_ram = ((val & 0x0F) == 0x0A);
return;
}
return;
/* Intentional fall through. */
case 0x2:
if(gb->mbc == 5)
{
@@ -819,7 +826,6 @@ void __gb_write(struct gb_s *gb, const uint_fast16_t addr, const uint8_t val)
}
/* Intentional fall through. */
case 0x3:
if(gb->mbc == 1)
{
@@ -829,12 +835,22 @@ void __gb_write(struct gb_s *gb, const uint_fast16_t addr, const uint8_t val)
if((gb->selected_rom_bank & 0x1F) == 0x00)
gb->selected_rom_bank++;
}
else if(gb->mbc == 2 && addr & 0x10)
else if(gb->mbc == 2)
{
gb->selected_rom_bank = val & 0x0F;
if(!gb->selected_rom_bank)
gb->selected_rom_bank++;
/* If bit 8 is 1, then set ROM bank number. */
if(addr & 0x100)
{
gb->selected_rom_bank = val & 0x0F;
/* Setting ROM bank to 0, sets it to 1. */
if(!gb->selected_rom_bank)
gb->selected_rom_bank++;
}
/* Otherwise set whether RAM is enabled or not. */
else
{
gb->enable_cart_ram = ((val & 0x0F) == 0x0A);
return;
}
}
else if(gb->mbc == 3)
{
@@ -876,10 +892,19 @@ void __gb_write(struct gb_s *gb, const uint_fast16_t addr, const uint8_t val)
case 0xA:
case 0xB:
/* Do not write to RAM if unavailable or disabled. */
if(gb->cart_ram && gb->enable_cart_ram)
{
if(gb->mbc == 3 && gb->cart_ram_bank >= 0x08)
gb->cart_rtc[gb->cart_ram_bank - 0x08] = val;
else if(gb->mbc == 2)
{
/* Only 9 bits are available in address. */
addr &= 0x1FF;
/* Data is only 4 bits wide in MBC2 RAM. */
val &= 0x0F;
gb->gb_cart_ram_write(gb, addr, val);
}
else if(gb->cart_mode_select &&
gb->cart_ram_bank < gb->num_ram_banks)
{
@@ -3380,6 +3405,11 @@ uint_fast32_t gb_get_save_size(struct gb_s *gb)
0x00, 0x800, 0x2000, 0x8000, 0x20000
};
uint8_t ram_size = gb->gb_rom_read(gb, ram_size_location);
/* MBC2 always has 512 half-bytes of cart RAM. */
if(gb->mbc == 2)
return 0x200;
return ram_sizes[ram_size];
}
@@ -3511,7 +3541,7 @@ enum gb_init_error_e gb_init(struct gb_s *gb,
};
const uint8_t cart_ram[] =
{
0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0,
0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0,
1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0
};
const uint16_t num_rom_banks_mask[] =
@@ -3558,6 +3588,10 @@ enum gb_init_error_e gb_init(struct gb_s *gb,
gb->num_rom_banks_mask = num_rom_banks_mask[gb->gb_rom_read(gb, bank_count_location)] - 1;
gb->num_ram_banks = num_ram_banks[gb->gb_rom_read(gb, ram_size_location)];
/* Note that MBC2 will appear to have no RAM banks, but it actually
* always has 512 half-bytes of RAM. Hence, gb->num_ram_banks must be
* ignored for MBC2. */
gb->lcd_blank = 0;
gb->display.lcd_draw_line = NULL;