redox/arch/x86_64/src/paging/temporary_page.rs

44 lines
1.5 KiB
Rust

//! Temporarily map a page
//! From [Phil Opp's Blog](http://os.phil-opp.com/remap-the-kernel.html)
use memory::Frame;
use super::{ActivePageTable, Page, VirtualAddress};
use super::entry::EntryFlags;
use super::table::{Table, Level1};
pub struct TemporaryPage {
page: Page,
}
impl TemporaryPage {
pub fn new(page: Page) -> TemporaryPage {
TemporaryPage {
page: page,
}
}
pub fn start_address (&self) -> VirtualAddress {
self.page.start_address()
}
/// Maps the temporary page to the given frame in the active table.
/// Returns the start address of the temporary page.
pub fn map(&mut self, frame: Frame, flags: EntryFlags, active_table: &mut ActivePageTable) -> VirtualAddress {
assert!(active_table.translate_page(self.page).is_none(), "temporary page is already mapped");
active_table.map_to(self.page, frame, flags);
self.page.start_address()
}
/// Maps the temporary page to the given page table frame in the active
/// table. Returns a reference to the now mapped table.
pub fn map_table_frame(&mut self, frame: Frame, flags: EntryFlags, active_table: &mut ActivePageTable) -> &mut Table<Level1> {
unsafe { &mut *(self.map(frame, flags, active_table).get() as *mut Table<Level1>) }
}
/// Unmaps the temporary page in the active table.
pub fn unmap(&mut self, active_table: &mut ActivePageTable) {
active_table.unmap(self.page)
}
}