Merge pull request #50 from rust-osdev/next

This Month in Rust OSDev (April 2021)

Author: phil-opp

content/this-month/2021-04/index.md

@@ -0,0 +1,181 @@
++++
+title = "This Month in Rust OSDev (April 2021)"
+date = 2021-05-05
+
+[extra]
+month = "April 2021"
+authors = [
+    "phil-opp",
+    "IsaacWoods",
+    # add yourself here
+]
++++
+
+Welcome to a new issue of _"This Month in Rust OSDev"_. In these posts, we 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) or using our [_comment form_](#comment-form) at the bottom of this page.
+
+<!--
+    This is a draft for the upcoming "This Month in Rust OSDev (April 2021)" 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
+
+### [`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.
+
+In April, we merged the following changes:
+
+- [Added XCR0 register](https://github.com/rust-osdev/x86_64/pull/239) <span class="gray">(published as `v0.13.5`)</span>
+- _Breaking:_ [Fixes for x86-interrupt calling convention](https://github.com/rust-osdev/x86_64/pull/242) <span class="gray">(published as `v0.14.0`)</span>
+- [Fix some warnings](https://github.com/rust-osdev/x86_64/pull/243)
+- [Add `sidt` support](https://github.com/rust-osdev/x86_64/pull/246)
+- [Fix `Debug` and `PartialEq` implementations for `IDT` entry type](https://github.com/rust-osdev/x86_64/pull/249)
+- [Looser trait bounds for `Port` types](https://github.com/rust-osdev/x86_64/pull/247)
+
+Thanks to [@Luis-Hebendanz](https://github.com/Luis-Hebendanz), [@CraftSpider](https://github.com/CraftSpider), and [@dbeckwith](https://github.com/dbeckwith) for their contributions!
+
+We also prepared a pull request to fix the build on the latest Rust nightlies:
+
+- Use new `const_fn_trait_bound` feature to fix build on latest nightly ([#250](https://github.com/rust-osdev/x86_64/pull/250))
+
+Since `rustfmt` is [currently broken](https://github.com/rust-lang/rust/issues/84538) on the affected newer nightlies, many users are still on older nightlies where the `const_fn_trait_bound` feature does not exist yet (`rustup update` skips nightlies where an installed component is missing). For this reason, we decided to wait with merging the fix until the `rustfmt` component is fixed. For people that want to use the latest nightly already, we pre-published the above fix as version `v0.14.1-beta`.
+
+### [`bootloader`](https://github.com/rust-osdev/bootloader)
+
+The `bootloader` crate implements a custom Rust-based bootloader for easy loading of 64-bit ELF executables. This month, we finally merged the UEFI rewrite branch:
+
+- [Rewrite for UEFI support](https://github.com/rust-osdev/bootloader/pull/130) <span class="gray">(published as `v0.10.0`)</span>
+
+This pull request changes the build process completely so that `v0.10.0` is no longer compatible with `v0.9.x` and below. Instead of using the [`bootimage`](https://github.com/rust-osdev/bootimage) crate, it is now recommended to create a custom builder crate. See the [API docs](https://docs.rs/bootloader/0.10.2/bootloader/) for more details. In addition to the build system changes, there are also some API changes such as a new `BootInfo` struct and a different system init state (e.g. a pixel-based framebuffer instead of the VGA text mode). Right now the documentation for the new version is still a bit sparse. We plan to improve this soon, including an update to the [_Writing an OS in Rust_](https://os.phil-opp.com/) blog (see below).
+
+In addition to the UEFI pull request, we merged the following changes this month:
+
+- [Fix documented type for entry point function](https://github.com/rust-osdev/bootloader/pull/147)
+- [`llvm_asm!` -> `asm!`](https://github.com/rust-osdev/bootloader/pull/154)
+- [Reduce the number of used unstable features of `x86_64` crate](https://github.com/rust-osdev/bootloader/pull/155) <span class="gray">(published as `v0.10.2`)</span>
+  - Backported as `v0.9.17` to fix compilation on latest nighlies.
+
+Thanks to [@mkroening](https://github.com/mkroening) and [@CraftSpider](https://github.com/CraftSpider) for their contributions!
+
+### [`xhci`](https://github.com/rust-osdev/xhci)
+
+The `xhci` crate provides types of xHCI structures such as Contexts, Extended Capabilities, Registers, and TRBs.
+
+Previously the repository was hosted under [`@toku-sa-n`](https://github.com/toku-sa-n). Since April, the Rust OSDev team hosts the repository.
+
+This crate is still under depelopment. Some types or field accessors may be missing. If you find missing features, feel free to send a PR!
+
+### [`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, we improved diagnostics by recording the original and target AML types in the `AmlError::IncompatibleValueConversion` error. This error is emitted when AML tries to convert a value
+to a data type that it can't be interpreted as - AML's rules on possible type conversions and where they can occur are very elaborate, so it helps to know the conversion that was actually attempted.
+<span class="gray">(published as `v0.12.0`)</span>
+
+Thanks to [@Knapsac](https://github.com/KnapSac) and [@toothbrush7777777](https://github.com/toothbrush7777777) for their contributions!
+
+### [`ovmf-prebuilt`](https://github.com/rust-osdev/ovmf-prebuilt)
+
+In order to make it easier to run UEFI disk images in [QEMU](https://www.qemu.org/) using [OVMF](https://github.com/tianocore/tianocore.github.io/wiki/OVMF), we created a new `ovmf-prebuilt` project this month. The projects automatically downloads the latest prebuilt OVMF RPM images from [Gerd Hoffman's firmware repository](https://www.kraxel.org/repos/) and publishes the extracted `OVMF_*.fd` files as [GitHub releases](https://github.com/rust-osdev/ovmf-prebuilt/releases). A new release is created daily through a CI script. Note that the licensing terms of the [`tianocore/edk2`](https://github.com/tianocore/edk2) repository apply to the released files.
+
+### [`uart_16550`](https://github.com/rust-osdev/uart_16550)
+
+The `uart_16550` crate provides basic support for serial port I/O for 16550-compatible UARTs. In April, we updated the `x86_64` dependency to fix the build on the latest nightlies:
+
+- [Update x86_64 dependency and make it more robust](https://github.com/rust-osdev/uart_16550/pull/14) <span class="gray">(published as `v0.2.13`)</span>
+
+This pull request also minimizes the number of unstable features that are enabled for the `x86_64` dependency to prevent breakage on future `const_fn` changes.
+
+### [`uefi-rs`](https://github.com/rust-osdev/uefi-rs)
+
+The `uefi` crate provides safe and performant wrappers for [UEFI](https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface), the successor to the BIOS. In April, we merged the following changes:
+
+- [Expose NamedFileProtocolInfo's Header types](https://github.com/rust-osdev/uefi-rs/pull/205)
+- [Upgrade to GitHub-native Dependabot](https://github.com/rust-osdev/uefi-rs/pull/207)
+
+Thanks to [@ocadaruma](https://github.com/ocadaruma) for their contribution!
+
+### [`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 fixed a compiler warning:
+
+- [Fix `spin_loop_hint` warning on Rust 1.51](https://github.com/rust-osdev/spinning_top/pull/10) <span class="gray">(published as `v0.2.3`)</span>
+
+
+## Call for Participation
+Want to contribute to a Rust OSDev project, but don't know where to start? Pick up one of these outstanding
+issues in one of our projects and get started!
+
+<!--
+Please use the following template for adding items:
+
+- [(`repo_name`) Issue Description](https://example.com/link-to-issue)
+-->
+
+<span class="gray">
+
+_No tasks were proposed for this section._
+
+</span>
+
+If you maintain a Rust OSDev project and are looking for contributors, especially for tasks suited to people
+getting started in this space, please [create a PR](https://github.com/rust-osdev/homepage/pulls) against the
+`next` branch with the tasks you want to include in the next issue.
+
+## 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>
+
+We merged the following improvements to the [_Writing an OS in Rust_] blog this month:
+
+- [Translate common texts into Chinese](https://github.com/phil-opp/blog_os/pull/962)
+- [Remove note about previously updated dependency](https://github.com/phil-opp/blog_os/pull/964)
+- [The `wake_trait` feature is now stable](https://github.com/phil-opp/blog_os/pull/963)
+- [Suggestion for `.cargo/config.toml` Explanation](https://github.com/phil-opp/blog_os/pull/974)
+- [Add missing word](https://github.com/phil-opp/blog_os/pull/960)
+- [Fix typo](https://github.com/phil-opp/blog_os/pull/978)
+
+Thanks to [@alexxroche](https://github.com/alexxroche), [@hi-rustin](https://github.com/hi-rustin), [@moomoolive](https://github.com/moomoolive), and [@kahirokunn](https://github.com/kahirokunn) for their contributions!
+
+We also made some further progress on the upcoming third edition of the blog:
+
+- [Minor improvements to UEFI code examples](https://github.com/phil-opp/blog_os/commit/0b9231f0ba57c189f747660f92bb1e4087e2b20b)
+- [Finish first draft of 'UEFI Booting' post](https://github.com/phil-opp/blog_os/commit/1aa7d21d8b3aabd3d4bb2e345f5590451e4dc2da)
+- [Resolve some TODOs](https://github.com/phil-opp/blog_os/commit/c61c37643aee942bea7c8dbbb235d0dffa6218bf)
+- [Explain how to run the disk images in QEMU (both BIOS and UEFI)](https://github.com/phil-opp/blog_os/commit/b3eace12608d9def1a996f5e2e46549858ba76c4)
+
+### [`cdrzewiecki/celos`](https://gitlab.com/cdrzewiecki/celos)
+
+<span class="gray">(Section written by [@drzewiec](https://github.com/drzewiec))</span>
+
+Over the past couple of months I have made some great strides on my OS.
+
+* Migrated the kernel to the higher half of virtual memory
+* Added double fault handling
+* Added page fault handling which will attempt to (safely) expand the kernel stack if it overflows
+* Related to the above, added more robust frame allocation
+* Added basic heap allocation
+
+Still working hard on squashing bugs, adding all of the things above gave me some pretty serious memory allocation bugs and it's taken me a while to get those worked out. I still want to do more testing to make sure I have all the bugs here worked out before moving on.
+
+Next steps will be to get nicer font drawing, and then attempt to implement process support.
+
+## 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).