riyyi/garbage
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Emulator: Add cartridge ROM bank loading

Browse Source
This commit is contained in:
Riyyi
2022-08-26 07:22:44 +02:00
parent 27abccf863
commit 81fe126068
4 changed files with 54 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/loader.cpp
+40 -4
View File
@@ -5,6 +5,7 @@
*/
#include <cstddef> // size_t
#include <cstdint> // uint32_t
#include "cpu.h"
#include "emu.h"
@@ -22,6 +23,19 @@ void Loader::loadRom(std::string_view rom_path)
init();
}
void Loader::disableBootrom()
{
Emu::the().removeMemorySpace("BOOTROM1");
Emu::the().removeMemorySpace("CARTHEADER");
Emu::the().removeMemorySpace("BOOTROM2");
// Load cartridge bank 0
Emu::the().addMemorySpace("CARTROM1", 0x0000, 0x3fff); // 16KiB
for (size_t i = 0x0000; i <= 0x3fff; ++i) {
Emu::the().writeMemory(i, m_rom_data[i]);
}
}
// -----------------------------------------
void Loader::init()
@@ -40,9 +54,10 @@ void Loader::init()
// https://gbdev.io/pandocs/Power_Up_Sequence.html
Emu::the().addMemorySpace("BOOTROM1", 0x0000, 0x00ff); // 256B
loadCartridgeHeader();
Emu::the().addMemorySpace("BOOTROM2", 0x0200, 0x08ff); // 1792B
Emu::the().addMemorySpace("BOOTROM2", 0x0200, 0x08ff); // 1792B
loadCartridgeBanks();
Emu::the().addMemorySpace("VRAM", 0x8000, 0x9fff, 2); // 8KiB * 2 banks
Emu::the().addMemorySpace("CARDRAM", 0xa000, 0xbfff, 1); // 8KiB * ? banks, if any
Emu::the().addMemorySpace("CARTRAM", 0xa000, 0xbfff, 1); // 8KiB * ? banks, if any
Emu::the().addMemorySpace("WRAM1", 0xc000, 0xcfff); // 4 KiB, Work RAM
Emu::the().addMemorySpace("WRAM2", 0xd000, 0xdfff, 7); // 4 KiB * 7 banks, Work RAM
Emu::the().addMemorySpace("ECHORAM", 0xe000, 0xfdff); // 7680B, Mirror of 0xc000~0xddff
@@ -84,9 +99,30 @@ void Loader::loadCartridgeHeader()
return;
}
Emu::the().addMemorySpace("CARTHEADER", 0x100, 0x14f);
Emu::the().addMemorySpace("CARTHEADER", 0x100, 0x14f); // 80B
for (size_t i = 0x100; i <= 0x14f; ++i) {
for (size_t i = 0x0100; i <= 0x014f; ++i) {
Emu::the().writeMemory(i, m_rom_data[i]);
}
}
void Loader::loadCartridgeBanks()
{
if (m_rom_data.empty()) {
return;
}
uint32_t rom_size = 32 * 1024 * (1 << m_rom_data[0x0148]);
uint32_t rom_banks = rom_size / (16 * 1024) - 1;
Emu::the().addMemorySpace("CARTROM2", 0x4000, 0x7fff, rom_banks); // 16KiB * banks
// Load cartridge bank 1~NN
auto rom_memory_spaces = Emu::the().memorySpace("CARTROM2");
for (size_t i = 0; i < rom_banks; ++i) {
for (size_t i = 0x4000; i <= 0x7fff; ++i) {
Emu::the().writeMemory(i, m_rom_data[i]);
}
rom_memory_spaces.active_bank += 1;
}
rom_memory_spaces.active_bank = 0;
}