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use core::ops::{Index, IndexMut}; use addr::PhysAddr; use super::PhysFrame; use ux::*; use usize_conversions::usize_from; pub struct PageTableEntry(u64); impl PageTableEntry { pub fn is_unused(&self) -> bool { self.0 == 0 } pub fn set_unused(&mut self) { self.0 = 0; } pub fn flags(&self) -> PageTableFlags { PageTableFlags::from_bits_truncate(self.0) } pub fn points_to(&self) -> Option<PhysAddr> { if self.flags().contains(PageTableFlags::PRESENT) { Some(PhysAddr::new(self.0 & 0x000fffff_fffff000)) } else { None } } pub fn set(&mut self, frame: PhysFrame, flags: PageTableFlags) { self.0 = (frame.start_address().as_u64()) | flags.bits(); } } bitflags! { pub struct PageTableFlags: u64 { const PRESENT = 1 << 0; const WRITABLE = 1 << 1; const USER_ACCESSIBLE = 1 << 2; const WRITE_THROUGH = 1 << 3; const NO_CACHE = 1 << 4; const ACCESSED = 1 << 5; const DIRTY = 1 << 6; const HUGE_PAGE = 1 << 7; const GLOBAL = 1 << 8; const BIT_9 = 1 << 9; const BIT_10 = 1 << 10; const BIT_11 = 1 << 11; const BIT_52 = 1 << 52; const BIT_53 = 1 << 53; const BIT_54 = 1 << 54; const BIT_55 = 1 << 55; const BIT_56 = 1 << 56; const BIT_57 = 1 << 57; const BIT_58 = 1 << 58; const BIT_59 = 1 << 59; const BIT_60 = 1 << 60; const BIT_61 = 1 << 61; const BIT_62 = 1 << 62; const NO_EXECUTE = 1 << 63; } } const ENTRY_COUNT: usize = 512; pub struct PageTable { entries: [PageTableEntry; ENTRY_COUNT], } impl PageTable { pub fn zero(&mut self) { for entry in self.entries.iter_mut() { entry.set_unused(); } } } impl Index<usize> for PageTable { type Output = PageTableEntry; fn index(&self, index: usize) -> &PageTableEntry { &self.entries[index] } } impl IndexMut<usize> for PageTable { fn index_mut(&mut self, index: usize) -> &mut PageTableEntry { &mut self.entries[index] } } impl Index<u9> for PageTable { type Output = PageTableEntry; fn index(&self, index: u9) -> &PageTableEntry { &self.entries[usize_from(u16::from(index))] } } impl IndexMut<u9> for PageTable { fn index_mut(&mut self, index: u9) -> &mut PageTableEntry { &mut self.entries[usize_from(u16::from(index))] } }