forked from M-Labs/zynq-rs
76 lines
1.6 KiB
Rust
76 lines
1.6 KiB
Rust
use core::mem::{align_of, size_of};
|
|
|
|
pub trait RAM {
|
|
#[inline(always)]
|
|
fn addr(&self) -> usize;
|
|
#[inline(always)]
|
|
fn size(&self) -> usize;
|
|
|
|
#[inline(always)]
|
|
fn into_memory_region(&self) -> MemoryRegion {
|
|
MemoryRegion {
|
|
addr: self.addr(),
|
|
size: self.size(),
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
pub struct MemoryRegion {
|
|
addr: usize,
|
|
size: usize,
|
|
}
|
|
|
|
impl MemoryRegion {
|
|
#[inline(always)]
|
|
fn split(&mut self, offset: usize) -> MemoryRegion {
|
|
if offset > self.size {
|
|
panic!("StaticAllocator: unable to split {}/{} bytes", offset, self.size);
|
|
}
|
|
|
|
let result = MemoryRegion {
|
|
addr: self.addr,
|
|
size: offset,
|
|
};
|
|
self.addr += offset;
|
|
self.size -= offset;
|
|
result
|
|
}
|
|
|
|
unsafe fn clear<T>(self) -> *mut T {
|
|
let result = self.addr as *mut T;
|
|
for b in core::slice::from_raw_parts_mut::<u8>(result as *mut u8, self.size) {
|
|
*b = 0;
|
|
}
|
|
result
|
|
}
|
|
|
|
pub fn align(&mut self, alignment: usize) {
|
|
let mask = alignment - 1;
|
|
let addr = (self.addr | mask) + 1;
|
|
self.size -= addr - self.addr;
|
|
self.addr = addr;
|
|
}
|
|
}
|
|
|
|
pub struct StaticAllocator {
|
|
free: MemoryRegion,
|
|
}
|
|
|
|
impl StaticAllocator {
|
|
pub fn new<R: RAM>(r: R) -> Self {
|
|
StaticAllocator {
|
|
free: r.into_memory_region(),
|
|
}
|
|
}
|
|
|
|
pub fn alloc<'a: 'b, 'b, T: Sized>(&'a mut self) -> &'b mut T {
|
|
self.free.align(align_of::<T>());
|
|
|
|
let size = size_of::<T>();
|
|
let region = self.free.split(size);
|
|
|
|
unsafe { &mut *region.clear() }
|
|
}
|
|
}
|