forked from AbleOS/ableos
55 lines
1.7 KiB
Rust
55 lines
1.7 KiB
Rust
use crate::memory::{MemoryManager, MAX_ORDER};
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use core::sync::atomic::AtomicU64;
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use limine::{MemmapEntry, MemoryMapEntryType, NonNullPtr};
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use spin::{Mutex, Once};
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use x86_64::{structures::paging::OffsetPageTable, VirtAddr};
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pub const PAGE_SIZE: usize = 4096;
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pub static MEMORY_MANAGER: Once<Mutex<MemoryManager>> = Once::new();
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pub static HHDM_OFFSET: AtomicU64 = AtomicU64::new(0);
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static PAGE_TABLE: Once<Mutex<OffsetPageTable>> = Once::new();
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/// Initialise page table
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pub unsafe fn init_pt(phys_base: VirtAddr) {
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log::info!("Retrieving page table");
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HHDM_OFFSET.store(phys_base.as_u64(), core::sync::atomic::Ordering::Relaxed);
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PAGE_TABLE.call_once(|| {
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Mutex::new(OffsetPageTable::new(
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&mut *((phys_base
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+ x86_64::registers::control::Cr3::read()
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.0
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.start_address()
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.as_u64())
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.as_mut_ptr()),
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phys_base,
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))
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});
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}
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/// Initialise memory manager
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pub fn initialize(mmap: &'static [NonNullPtr<MemmapEntry>]) {
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let mut memory_manager = MemoryManager::new();
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for entry in mmap {
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if entry.typ != MemoryMapEntryType::Usable {
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continue;
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}
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let alignment = PAGE_SIZE << MAX_ORDER;
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let start_addr_unaligned = entry.base as usize;
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let diff = alignment - start_addr_unaligned % alignment;
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if diff > entry.len as usize {
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continue;
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}
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let start_addr = start_addr_unaligned + diff;
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let page_count = (entry.len as usize - diff) / PAGE_SIZE;
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unsafe {
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memory_manager.add_range(start_addr.into(), page_count);
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}
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}
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MEMORY_MANAGER.call_once(|| Mutex::new(memory_manager));
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}
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