atreyabain/byte-pusher-emu
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[mem] Add memset

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Atreya Bain
2024-02-18 19:24:49 +05:30
parent 7492ba8dd3
commit ba1c1a1412
1 changed files with 33 additions and 10 deletions
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43
src/emu/iomem.rs
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@@ -1,6 +1,7 @@
use crate::emu::mmu::Memory;
use crate::emu::program_counter::ProgramCounter;
use crate::misc::emulator_error::EmulatorError;
use crate::misc::emulator_error::{DeviceType, EmulatorError};
use crate::misc::emulator_error::DeviceType::MMU;
use crate::misc::endian::{read_big_endian_u16, read_big_endian_u24};
use crate::misc::result::EmulatorResult;
@@ -14,6 +15,7 @@ pub struct MemoryMappedIO {
//FIXME use a device
audio_sample_address_base: [u8; 2],
}
/// Represents the memory mapped segment of IO. Aggregates the mapping logic.
impl MemoryMappedIO {
// 2 byte keyboard bits
@@ -51,24 +53,45 @@ impl Memory for MemoryMappedIO {
let addr_usize = address as usize;
let keyboard_byte = self.keyboard_bytes[addr_usize];
log::trace!("Fetching keyboard({}) byte segment {} -> {}",read_big_endian_u16(&self.keyboard_bytes),address,keyboard_byte);
keyboard_byte
Ok(keyboard_byte)
}
Self::PC_START_ADDR..=Self::PC_END_ADDR => {
let pc_index = address - Self::PC_START_ADDR;
self.program_counter.try_get_byte(pc_index)?
self.program_counter.try_get_byte(pc_index)
}
Self::PIXEL_BASE => {
log::trace!("Fetching pixel base reg {}",self.pixel_reg);
self.pixel_reg
Ok(self.pixel_reg)
}
Self::AUDIO_SAMPLE_BASE_START => Ok(self.audio_sample_address_base[0]),
Self::AUDIO_SAMPLE_BASE_END => Ok(self.audio_sample_address_base[1]),
address => {
Err(EmulatorError::UnreachableMemory(DeviceType::MMU, address))
}
Self::AUDIO_SAMPLE_BASE_START => self.audio_sample_address_base[0],
Self::AUDIO_SAMPLE_BASE_END => self.audio_sample_address_base[1],
_ => { panic!("Unreachable code") }
};
Ok(byte)
byte
}
fn try_set_byte(&mut self, address: u32, val: u8) -> EmulatorResult<()> {
todo!()
fn try_set_byte(&mut self, address: u32, byte_value: u8) -> EmulatorResult<()> {
match address {
Self::KEYBOARD_BIT_START..=Self::KEYBOARD_BIT_END => {
let addr_usize = address as usize;
let keyboard_byte = self.keyboard_bytes[addr_usize];
log::trace!("Setting keyboard({}) byte segment {} -> {}",read_big_endian_u16(&self.keyboard_bytes),address,keyboard_byte);
self.keyboard_bytes[addr_usize] = byte_value;
}
Self::PC_START_ADDR..=Self::PC_END_ADDR => {
let pc_index = address - Self::PC_START_ADDR;
self.program_counter.try_set_byte(pc_index, byte_value)?
}
Self::PIXEL_BASE => {
log::trace!("Fetching pixel base reg {}",self.pixel_reg);
self.pixel_reg = byte_value
}
Self::AUDIO_SAMPLE_BASE_START => { self.audio_sample_address_base[0] = byte_value }
Self::AUDIO_SAMPLE_BASE_END => { self.audio_sample_address_base[1] = byte_value }
_ => { return Err(EmulatorError::UnreachableMemory(MMU, address)); }
};
Ok(())
}
}