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Move Frame::start_address to memory/mod.rs and use it in identity_map()

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This commit is contained in:
Philipp Oppermann
2015-12-07 10:56:26 +01:00
parent 6ed376112d
commit b314d4827f
4 changed files with 12 additions and 15 deletions
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14
posts/DRAFT-paging.md
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@@ -130,18 +130,16 @@ pub fn set(&mut self, frame: Frame, flags: EntryFlags) {
```
The start address of a frame should be page aligned and smaller than 2^52 (since x86 uses 52bit physical addresses). Since an invalid address could mess up the entry, we add an assertion. To actually set the entry, we just need to `or` the start address and the flag bits.
The missing `start_address` function is pretty simple:
The missing `Frame::start_address` method is pretty simple:
```rust
use memory::paging::PhysicalAddress;
use self::paging::PhysicalAddress;
impl Frame {
fn start_address(&self) -> PhysicalAddress {
self.number << 12
}
fn start_address(&self) -> PhysicalAddress {
self.number * PAGE_SIZE
}
```
Since we only need it in the entry submodule, we put it in a new `impl Frame` block in `entry.rs`.
We add it to the `impl Frame` block in `memory/mod.rs`.
### Page Tables
To model page tables, we create a basic `Table` struct in a new `table` submodule:
@@ -640,7 +638,7 @@ pub fn identity_map<A>(&mut self,
allocator: &mut A)
where A: FrameAllocator
{
let page = Page { number: frame.number };
let page = Page::containing_address(frame.start_address());
self.map_to(&page, frame, flags, allocator)
}
```