blog_os/blog/content/status-update/2020-01-07.md

+++ title = "Updates in December 2019" date = 2020-01-07 +++

Happy New Year!

This post gives an overview of the recent updates to the Writing an OS in Rust blog and the corresponding libraries and tools.

blog_os

The repository of the Writing an OS in Rust blog received the following updates:

• Update x86_64 dependency to version 0.8.1. This included the dependency update itself, an update of the frame allocation code, and an update of the blog.
• License the blog/content folder under CC BY-NC
• Reword sentence in first post by @pamolloy

Further, we're still working on adding Experimental Support for Community Translations to the blog, starting with Simplified Chinese and Traditional Chinese. Any help is appreciated!

bootloader

There were no updates to the bootloader this month.

I'm currently working on rewriting the 16-bit/32-bit stages in Rust and making the bootloader more modular in the process. This should make it much easier to add support for UEFI and GRUB booting later.

bootimage

There were no updates to the bootimage tool this month.

x86_64

We landed a number of breaking changes this month:

• Replace ux dependency with custom wrapper structs
• Add new UnusedPhysFrame type and use it in Mapper::map_to
• Make Mapper trait object safe by adding Self: Sized bounds on generic functions
• Rename divide_by_zero field of IDT to divide_error
• Introduce new diverging handler functions for exceptions classified as "abort"

These changes were released an version 0.8.0. Unfortunately, there was a missing re-export for the new UnusedPhysFrame type. We fixed it in #110 and released the fix as version 0.8.1.

There was one more addition to the x86_64 crate afterwards:

• Add support for cr4 control register (with complete documentation) by @KarimAllah (released as version 0.8.2).

There were also a few changes related to continuous integration:

• Remove bors from this repo
• Run 'push' builds only for master branch
• Remove Travis CI and Azure Pipelines scripts
• Add caching of cargo crates to GitHub Actions CI

cargo-xbuild

The cargo-xbuild crate, which cross-compiles the sysroot, received the following updates this month:

• Add --quiet flag that suppresses "waiting for file lock" message by @Nils-TUD (published as version 0.5.19)
• Fix wrong feature name for memcpy=false (released as version 0.5.20)