diff options
Diffstat (limited to 'src/mapper.rs')
-rw-r--r-- | src/mapper.rs | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/mapper.rs b/src/mapper.rs new file mode 100644 index 0000000..d83157a --- /dev/null +++ b/src/mapper.rs @@ -0,0 +1,55 @@ +use memory::VMem; +use cartridge::{Cartridge, BankType}; +pub struct Mapper2<'a, T: 'a> where T: Cartridge { + cart: &'a T, + prg_bank1: &'a [u8], + prg_bank2: &'a [u8], + chr_bank: &'a mut [u8], + sram: &'a mut [u8], + bank_num: usize +} + +impl<'a, T> VMem for Mapper2<'a, T> where T: Cartridge { + fn read(&self, addr: u16) -> u8 { + let addr = addr as usize; + if addr < 0x2000 { + self.chr_bank[addr] + } else if addr >= 0xc000 { + self.prg_bank2[addr - 0xc000] + } else if addr >= 0x8000 { + self.prg_bank1[addr - 0x8000] + } else if addr >= 0x6000 { + self.sram[addr - 0x6000] + } else { + panic!("unmapped address: 0x{:04x}", addr) + } + } + + fn write(&mut self, addr: u16, data: u8) { + let addr = addr as usize; + if addr < 0x2000 { + self.chr_bank[addr] = data; + } else if addr >= 0x8000 { + self.prg_bank1 = unsafe {&*self.cart.get_bank( + data as usize % self.bank_num, BankType::PRG_ROM)}; + } else if addr >= 0x6000 { + self.sram[addr - 0x6000] = data; + } else { + panic!("invalid write to address: 0x{:04x}", addr); + } + } +} + +impl<'a, T> Mapper2<'a, T> where T: Cartridge { + fn new(cart: &'a mut T) -> Self { + let bank_num = cart.get_bank_num(BankType::PRG_ROM); + unsafe { + Mapper2{cart, + prg_bank1: &*cart.get_bank(0, BankType::PRG_ROM), + prg_bank2: &*cart.get_bank(bank_num - 1, BankType::PRG_ROM), + chr_bank: &mut *cart.get_bank(0, BankType::CHR_ROM), + sram: &mut *cart.get_bank(0, BankType::SRAM), + bank_num} + } + } +} |