Function map_consecutive_pages

kernel/src/memory.rs:388–426

Map a consecutive set of pages to a consecutive set of frames level_4_physaddr The physical address of the L4 pagetable start_page First page in the sequence start_frame First frame in the sequence num_frames Number of consecutive frames

(
    level_4_physaddr: u64,
    start_page: Page,
    start_frame: PhysFrame,
    num_frames: u64)

/// start_frame     First frame in the sequence
/// num_frames      Number of consecutive frames
fn map_consecutive_pages(
    level_4_physaddr: u64,
    start_page: Page,
    start_frame: PhysFrame,
    num_frames: u64)
    -> Result<PhysAddr, MapToError<Size4KiB>> {

    let frame_range = PhysFrame::range(start_frame, start_frame + num_frames);
    let page_range = Page::range(start_page, start_page + num_frames);

    let memory_info = unsafe {MEMORY_INFO.as_mut().unwrap()};

    let l4_table: &mut PageTable = unsafe {
        &mut *(memory_info.physical_memory_offset
               + level_4_physaddr).as_mut_ptr()};

    let frame_allocator = &mut memory_info.frame_allocator;

    let mut mapper = unsafe {
        OffsetPageTable::new(l4_table,
                             memory_info.physical_memory_offset)};

    for (page, frame) in page_range.zip(frame_range) {
        unsafe {
            mapper.map_to_with_table_flags(page,
                                           frame,
                                           // Writeable by user
                                           PageTableFlags::PRESENT |
                                           PageTableFlags::WRITABLE |
                                           PageTableFlags::USER_ACCESSIBLE,
                                           // Parent table flags include writable
                                           PageTableFlags::PRESENT |
                                           PageTableFlags::WRITABLE |
                                           PageTableFlags::USER_ACCESSIBLE,
                                           frame_allocator)?.flush()
        };
    }
    Ok(start_frame.start_address())
}

/// Allocates a consecutive set of frames
///