Files
DSA/dsa/emulator/src/memory/ram/prealloc.rs
T

51 lines
1.3 KiB
Rust

use crate::memory::{
PhysAddr, RandomAccessMemory,
ram::{NUM_PAGES, Page},
};
pub struct PreAllocStore {
heap: Box<[u8; NUM_PAGES * 4096]>,
}
unsafe impl Send for PreAllocStore {}
impl PreAllocStore {
pub fn new() -> Self {
Self {
heap: unsafe { Box::new_zeroed().assume_init() },
}
}
}
impl RandomAccessMemory for PreAllocStore {
#[inline(always)]
fn read_word(&self, addr: PhysAddr) -> u32 {
unsafe { (self.heap.as_ptr().add(addr as usize) as *const u32).read() }
}
#[inline(always)]
fn read_byte(&self, addr: PhysAddr) -> u8 {
self.heap[addr as usize]
}
#[inline(always)]
fn read_page(&self, addr: PhysAddr) -> &Page {
debug_assert_eq!(addr % 4096, 0);
unsafe { (self.heap.as_ptr().add(addr as usize) as *const Page).as_ref_unchecked() }
}
#[inline(always)]
fn write_byte(&mut self, addr: PhysAddr, value: u8) {
self.heap[addr as usize] = value;
}
#[inline(always)]
fn write_word(&mut self, addr: PhysAddr, value: u32) {
unsafe { (self.heap.as_ptr().add(addr as usize) as *mut u32).write(value) };
}
#[inline(always)]
fn write_page(&mut self, addr: PhysAddr, value: &Page) {
self.heap[addr as usize..addr as usize + 4096].copy_from_slice(value);
}
}