Merge pull request #19 from rust-osdev/next

This Month in Rust OSDev (August 2020)

Author: phil-opp

content/this-month/2020-08.md

@@ -0,0 +1,169 @@
++++
+title = "This Month in Rust OSDev (August 2020)"
+date = 2020-09-07
+
+[extra]
+month = "August 2020"
+authors = [
+    "phil-opp",
+    "JohnTitor",
+    # add yourself here
+]
++++
+
+Welcome to a new issue of _"This Month in Rust OSDev"_. In these posts, we will give a regular overview of notable changes in the Rust operating system development ecosystem.
+
+<!-- more -->
+
+This series is openly developed [on GitHub](https://github.com/rust-osdev/homepage/). Feel free to open pull requests there with content you would like to see in the next issue. If you find some issues on this page, please report them by [creating an issue](https://github.com/rust-osdev/homepage/issues/new).
+
+<!--
+    This is a draft for the upcoming "This Month in Rust OSDev (August 2020)" post.
+    Feel free to create pull requests against the `next` branch to add your
+    content here.
+    Please take a look at the past posts on https://rust-osdev.com/ to see the
+    general structure of these posts.
+-->
+
+## Project Updates
+
+In this section, we give an overview of notable changes to the projects hosted under the [`rust-osdev`] organization.
+
+[`rust-osdev`]: https://github.com/rust-osdev/about
+
+### [`uefi-rs`](https://github.com/rust-osdev/uefi-rs)
+
+The `uefi-rs` crate provides safe and performant wrappers for [UEFI](https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface), the successor to the BIOS. In August, the crate received a large number of improvements:
+
+- [Add method to return (image_base, image_size) to LoadedImage](https://github.com/rust-osdev/uefi-rs/pull/149)
+- [Rename `image_info` to `info`](https://github.com/rust-osdev/uefi-rs/pull/153)
+- [Hide the `MemoryMapIter` type from the API](https://github.com/rust-osdev/uefi-rs/pull/154)
+- [Upstream two changes from Pebble's fork](https://github.com/rust-osdev/uefi-rs/pull/156)
+- [Update to new `alloc` API](https://github.com/rust-osdev/uefi-rs/pull/157)
+- [Publish new versions of the crates](https://github.com/rust-osdev/uefi-rs/pull/158)
+- [Make memory map iterator clonable](https://github.com/rust-osdev/uefi-rs/pull/161)
+- [Fix the `text::Output::current_mode` method](https://github.com/rust-osdev/uefi-rs/pull/163)
+- [Use exact size iterators where possible](https://github.com/rust-osdev/uefi-rs/pull/164)
+- [Use `ExactSizeIterator` in `exit_boot_services`](https://github.com/rust-osdev/uefi-rs/pull/165)
+
+Thanks to [@tomoyat1](https://github.com/tomoyat1) for their contribution!
+
+### [`multiboot2`](https://github.com/rust-osdev/multiboot2-elf64)
+
+The `multiboot2` crate provides abstraction types for the boot information of multiboot2 bootloaders. The most important change this month was the update to the latest release of the multiboot2 specification:
+
+- [Add support for multiboot2](https://github.com/rust-osdev/multiboot2-elf64/pull/66)
+- [Improve usage of repr(packed)](https://github.com/rust-osdev/multiboot2-elf64/pull/68)
+
+Thanks to [@Caduser2020](https://github.com/Caduser2020) for these contributions and welcome to the `multiboot2` team!
+
+### [`bootloader`](https://github.com/rust-osdev/bootloader)
+
+The [`bootloader` crate](https://github.com/rust-osdev/bootloader) implements a custom Rust-based bootloader for easy loading of 64-bit ELF executables. We did not publish any changes to the bootloader crate this month, but we made good progress on the UEFI implementation. See [these issue comments](https://github.com/phil-opp/blog_os/issues/349#issuecomment-677645694) for a detailed status report.
+
+The rewrite of the real mode and protected mode stages of the BIOS bootloader is also [making progress](https://gitter.im/rust-osdev/bootloader?at=5f4594ed9566774dfe3167bc). The goal is to replace as much of the existing assembly code with Rust as possible, in order to make the code more robust and easier to understand.
+
+### [`ansi_rgb`](https://github.com/rust-osdev/ansi_rgb)
+
+The `ansi_rgb` crate implements `no_std`-compatible support for colored terminal text using ANSI escape sequences. The crate is still in an early state, but it received lots of new features this month:
+
+- [More colors and some minor changes](https://github.com/rust-osdev/ansi_rgb/pull/11)
+- [Demo using RGB and 3- and 4-bit colors](https://github.com/rust-osdev/ansi_rgb/commit/19891574e3a4df81716973cf4c88ad965596c043)
+- [Merge `Foreground` and `Background` traits](https://github.com/rust-osdev/ansi_rgb/commit/ebcb75b4f273fdeaef6fde051ca5dccb83560c13)
+- [Add 8-bit colors](https://github.com/rust-osdev/ansi_rgb/commit/d6ed54ae50ab3653f9c94275efc369472c5278a9)
+- [Combine `WithForeground` and `WithBackground` into `Colored`](https://github.com/rust-osdev/ansi_rgb/commit/0d77122be5a449a9c03f04421d43df90a7fd708e)
+- [Document extension to other color types](https://github.com/rust-osdev/ansi_rgb/commit/9e10f6bac075b980cef66f4ddc9efab25c0a5504)
+- [Add Color8 constructors for RGB and gray](https://github.com/rust-osdev/ansi_rgb/pull/12)
+- [Fix bounds check for Color8::new_rgb](https://github.com/rust-osdev/ansi_rgb/pull/13)
+- [Go back to `WithForeground` and `WithBackground` structs](https://github.com/rust-osdev/ansi_rgb/commit/3eb8c16681878ae97f8249524609f0611d9eddf6)
+- [Fix (and document/test) nesting](https://github.com/rust-osdev/ansi_rgb/commit/9dd8d1828b1d0b3b707cb1f22c28074a6ce82ca5)
+
+Thanks to [@hanmertens](https://github.com/hanmertens) for their contributions!
+
+### [`bootimage`](https://github.com/rust-osdev/bootimage)
+
+The `bootimage` tool allows the creation of bootable disk images for `bootloader`-based kernels. It also provides a runner executable for `cargo` to make `cargo run` and `cargo test` work using QEMU. In August, we changed the test behavior to fix a bug where a triple fault is interpreted as a test success. We also fixed a small bug related to the `--version` argument. The relevant pull requests are:
+
+- [Consider all other exit codes besides 'test-success-exit-code' as failures](https://github.com/rust-osdev/bootimage/pull/65) <span class="gray">(published as `v0.10.0`)</span>
+    - Also runs tests with -no-reboot by default, configurable through a new test-no-reboot config key
+    - This is technically **breaking change**, but it should not affect most people.
+- [Parse `--version` argument without subcommand (`bootimage --version`)](https://github.com/rust-osdev/bootimage/pull/67) <span class="gray">(published as `v0.10.1`)</span>
+
+Thanks to [@Freax13](https://github.com/Freax13) for their contribution!
+
+### [`x86_64`](https://github.com/rust-osdev/x86_64)
+
+The `x86_64` crate provides various abstractions for `x86_64` systems, including wrappers for CPU instructions, access to processor-specific registers, and abstraction types for architecture-specific structures such as page tables and descriptor tables.
+
+This month, we added some functions for reading and writing the `FS` and `GS` segment base registers:
+
+- [Add rdfsbase, rdgsbase, wrfsbase, wrgsbase](https://github.com/rust-osdev/x86_64/pull/172) <span class="gray">(published as `v0.11.2`)</span>
+
+Thanks to [@haraldh](https://github.com/haraldh) for this contribution!
+
+### [`acpi`](https://github.com/rust-osdev/acpi)
+
+The `acpi` repository contains crates for parsing the ACPI tables – data structures that the firmware of modern computers use to relay information about the hardware to the OS. This month, support for more opcodes was added to the AML parser:
+
+- [Factor out value comparison code from DefLEqual](https://github.com/rust-osdev/acpi/commit/438bd9e4cc98bdac29a9eeccf0877592dd70c540)
+- [Make all type-2 opcode parsers concrete to avoid type limit](https://github.com/rust-osdev/acpi/commit/28e46b3cd2f68b033ae9559d84e0d8784a527422)
+- [Implement some `DefL*` opcodes](https://github.com/rust-osdev/acpi/compare/438bd9e4cc98bdac29a9eeccf0877592dd70c540...8dd5b21cf225e267d9786036ed134a45fc34b5f1)
+- [Only read from field if update rule is Preserve](https://github.com/rust-osdev/acpi/commit/e54158ee0128c47acb5e34509e390010ee1feb74)
+
+### [`spinning_top`](https://github.com/rust-osdev/spinning_top)
+
+The `spinning_top` crate provides a simple spinlock implementation based on the abstractions of the [`lock_api`](https://docs.rs/lock_api/0.4.1/lock_api/) crate. This month, we added an optional feature to make the crate compatible with the `owning_ref` crate:
+
+- [Add owning_ref support](https://github.com/rust-osdev/spinning_top/pull/7) <span class="gray">(published as `v0.2.2`)</span>
+
+Thanks to [@not-a-seagull](https://github.com/not-a-seagull) for this contribution!
+
+### [`cargo-xbuild`](https://github.com/rust-osdev/cargo-xbuild)
+
+The `cargo-xbuild` project provides `cargo` command wrappers to cross-compile the sysroot crates `core` and `alloc`. At the beginning of this month, we had to update the crate for the new rustc directory layout. The crate also received a small cleanup:
+
+- [Update cargo-xbuild to new rust directory layout](https://github.com/rust-osdev/cargo-xbuild/pull/87) <span class="gray">(published as `v0.6.0`)</span>
+- [Cleanup: Use eprintln! instead of writeln! with stderr](https://github.com/rust-osdev/cargo-xbuild/pull/86)
+
+Thanks to [@toku-sa-n](https://github.com/toku-sa-n) for their contribution!
+
+Even though we still maintain the `cargo-xbuild` crate, we recommend switching to cargo's own `build-std` feature that is always up-to-date with the latest Rust/Cargo changes. We wrote a short guide on how to switch to it, which is available [in our Readme](https://github.com/rust-osdev/cargo-xbuild#alternative-the-build-std-feature-of-cargo).
+
+## Personal Projects
+
+In this section, we describe updates to personal projects that are not directly related to the `rust-osdev` organization. Feel free to [create a pull request](https://github.com/rust-osdev/homepage/pulls) with the updates of your OS project for the next post.
+
+### [`phil-opp/blog_os`](https://github.com/phil-opp/blog_os)
+
+<span class="gray">(Section written by [@phil-opp](https://github.com/phil-opp))</span>
+
+I'm still mostly working on the new bootloader with UEFI support, so there were no major changes to the _Writing an OS in Rust_ series this month. However, I'm making good progress on the bootloader [as noted above](#bootloader) and I hope to finish the rewrite soon.
+
+If all goes well, the new version will no longer require the `bootimage` tool and instead let the users create a simple build script for the bootloader themselves. It will also set up a pixel based framebuffer, which means that we will be able to do display proper graphics instead of just VGA-based text. Unfortunately, I'm currently a bit blocked by limitations of cargo configuration files (our default target should not apply to our build script), but I hope that we can [find a solution for this](https://github.com/rust-lang/cargo/issues/8687) soon.
+
+While I focused most of my time on the bootloader and the cargo config files, I also merged a few few minor improvements for my blog:
+
+- [Change `rustup override add` to `rustup override set`](https://github.com/phil-opp/blog_os/pull/843)
+- [Add (initial) Japanese translation](https://github.com/phil-opp/blog_os/pull/845) (see below)
+- [Increase double fault stack size in Double Faults post](https://github.com/phil-opp/blog_os/commit/0425bd3c819bd26910c4e82a7a24c2a5126d4116)
+    - The previous stack size was too small in debug mode since our double fault handler uses the rather stack-intensive `core::fmt` functions.
+    - Since the dobule fault stack has no guard page, this stack overflow [resulted in undefined behavior](https://github.com/phil-opp/blog_os/issues/449#issuecomment-667638975). For example, it caused the system to hang or lead to a triple fault.
+    - The stack size increase only works around this problem, but is not a clear fix. I plan to introduce a proper stack allocation function in the upcoming post about threading, which will create stacks with a proper guard page so that stack overflows deterministically lead to a page fault.
+- [Use workflow dispatch event to trigger scheduled builds of code branches](https://github.com/phil-opp/blog_os/pull/846)
+    - Enables nightly builds of all `post-XX` branches, so that we can be sure that our code always builds with the latest Rust nightly versions.
+- [Update Zola to 0.11.0](https://github.com/phil-opp/blog_os/pull/850)
+
+Thanks to [@RWOverdijk](https://github.com/RWOverdijk) and [@JohnTitor](https://github.com/JohnTitor) for their contributions!
+
+#### Japanese translations
+
+<span class="gray">(Section written by [@JohnTitor](https://github.com/JohnTitor))</span>
+
+This month, we also [added a Japanese translation](https://github.com/phil-opp/blog_os/pull/845) newly. You can find the languages list in the sidebar and Japanese if you enable that language in your browser.
+Only one post is currently translated, but we'd like to translate more posts in the future.
+Want to participate in the translation or find a typo? Feel free to open a PR/issue on [the repository](https://github.com/phil-opp/blog_os)
+(please use English in the description if possible)!
+
+## Join Us?
+
+Are you interested in Rust-based operating system development? Our `rust-osdev` organization is always open to new members and new projects. Just let us know if you want to join! A good way for getting in touch is our [gitter channel](https://gitter.im/rust-osdev/Lobby).