Paging Implementation (zh-CN)

[giscus[bot]]

Paging Implementation (zh-CN)

这篇文章展示了如何在我们的内核中实现分页支持。它首先探讨了使物理页表帧能够被内核访问的不同技术，并讨论了它们各自的优点和缺点。然后，它实现了一个地址转换功能和一个创建新映射的功能。

https://os.phil-opp.com/zh-CN/paging-implementation/

[rushjam]

Nice Content

[Aria-iu]

boot process is complex , using too much crates makes it's ...

[PengXuanyao]

Encountered an Error at let page = Page::containing_address(VirtAddr::new(0xdeadbeaf000)); :

Error[E0283]: type annotations needed for `x86_64::structures::paging::Page<_>`
  --> src/main.rs:27:9
   |
27 |     let page = Page::containing_address(VirtAddr::new(0xdeadbeaf000));
   |         ^^^^   ---- type must be known at this point
   |
   = note: cannot satisfy `_: PageSize
help: the following types implement trait `PageSize`
  --> /Users/pxy/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/x86_64-0.14.13/src/structures/paging/page.rs:38:1
   |
38 | impl PageSize for Size4KiB {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ `x86_64::structures::paging::Size4KiB`
...
45 | impl PageSize for Size2MiB {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ `x86_64::structures::paging::Size2MiB`
...
52 | impl PageSize for Size1GiB {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ `x86_64::structures::paging::Size1GiB`
note: required by a bound in `x86_64::structures::paging::Page`
  --> /Users/pxy/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/x86_64-0.14.13/src/structures/paging/page.rs:60:20
   |
60 | pub struct Page<S: PageSize = Size4KiB> {
   |                    ^^^^^^^^ required by this bound in `Page`
help: consider giving `page` an explicit type, where the type for type parameter `S` is
   |
27 |     let page: x86_64::structures::paging::Page<S> = Page::containing_address(VirtAddr::new(0xdeadbeaf000));

According to the suggestion and annotating the type of page, the problem was solved. (This may be caused by a newer version of Rust?)

Solution:

fn kernel_main(boot_info: &'static BootInfo) -> ! {
    use x86_64::structures::paging::Size4KiB;
    […]
    let page: x86_64::structures::paging::Page<Size4KiB> =
        Page::containing_address(VirtAddr::new(0xdeadbeaf000));
    […]
}