atreyabain/byte-pusher-emu
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[dbg] Add endian order operations

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Atreya Bain
2024-02-17 08:44:14 +05:30
parent 9314888e99
commit 757d01fc25
9 changed files with 49 additions and 23 deletions
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24
src/emu/iomem.rs
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@@ -1,32 +1,42 @@
use crate::emu::mmu::Memory;
use crate::misc::endian::MemoryOperations;
#[derive(Debug, Copy, Clone)]
pub struct MemoryMappedIO {
keyboard_bits: [u8;2],
//FIXME use a keyboard
keyboard_bytes: [u8;2],
program_counter: [u8; 3],
//FIXME use a device
pixel_reg: u8,
//FIXME use a device
audio_sample_address_base: [u8; 2],
}
impl MemoryMappedIO {
pub fn new() -> MemoryMappedIO {
MemoryMappedIO {
keyboard_bits: [0,0],
keyboard_bytes: [0,0],
program_counter: [0, 0, 0],
pixel_reg: 0,
audio_sample_address_base: [0, 0],
}
}
}
// 2 byte keyboard bits
const KEYBOARD_BIT_START: u32 = 0;
const KEYBOARD_BIT_END: u32 = 1;
// 3 bytes PC
const PC_START_ADDR: u32 = 2;
const PC_LEN: u32 = 3;
const PC_END_ADDR: u32 = PC_START_ADDR + PC_LEN - 1;
// 1 byte pixel base reg
const PIXEL_BASE: u32 = 5;
// 2 byte audio sample base reg
const AUDIO_SAMPLE_BASE_START: u32 = 6;
const AUDIO_SAMPLE_BASE_LEN: u32 = 2;
const AUDIO_SAMPLE_BASE_END: u32 = AUDIO_SAMPLE_BASE_START + AUDIO_SAMPLE_BASE_LEN - 1;
@@ -36,13 +46,15 @@ impl Memory for MemoryMappedIO {
match address {
KEYBOARD_BIT_START..=KEYBOARD_BIT_END => {
let addr_usize = address as usize;
log::trace!("Fetching keyboard bits segment {}",addr_usize);
self.keyboard_bits[addr_usize]
let keyboard_byte = self.keyboard_bytes[addr_usize];
log::trace!("Fetching keyboard({}) byte segment {} -> {}",MemoryOperations::read_big_endian_u16(&self.keyboard_bytes),address,keyboard_byte);
keyboard_byte
},
PC_START_ADDR..=PC_END_ADDR => {
let pc_index = (address - PC_START_ADDR) as usize;
log::trace!("Fetching PC {:?} bit segment {}",self.program_counter,pc_index);
self.program_counter[pc_index]
let pc_byte = self.program_counter[pc_index];
log::trace!("Fetching PC({}) byte segment {} -> {}",MemoryOperations::read_big_endian_u24(&self.program_counter),pc_index,pc_byte);
pc_byte
},
PIXEL_BASE => {
log::trace!("Fetching pixel base reg {}",self.pixel_reg);