Various improvements

Author: phil-opp

content/this-month/2026-04/index.md

@@ -1,6 +1,6 @@
 +++
 title = "This Month in Rust OSDev: April 2026"
-date = 2026-05-05
+date = 2026-05-14
 
 [extra]
 month = "April 2026"
@@ -17,7 +17,7 @@ Please submit interesting posts and projects for the next issue [on Zulip](https
 
 <span class="gray">
 Disclaimer: Automated scripts and AI assistance were used for collecting and categorizing links.
-Everything was proofread and checked manually and there were many manual tweaks.
+Everything was proofread and checked manually, with many manual tweaks.
 </span>
 
 
@@ -40,18 +40,22 @@ Please follow this template:
   - (optional) Some additional context
 -->
 
-- [octopos: xv6 based operating system for RISC-V in Rust](https://www.boranseckin.com/projects/octopos)
+- [octopos: xv6-based operating system for RISC-V in Rust](https://www.boranseckin.com/projects/octopos)
   - A Rust port of xv6 that targets RISC-V and runs without the standard library, including process management, Sv39 page tables, VirtIO disk support, and a POSIX-style syscall interface.
+- [A minimal VMM in Rust with Apple Hypervisor](https://gigapotential.dev/blog/minimal-vmm-in-rust-with-apple-hypervisor/)
+  - Walks through building a small virtual machine monitor on Apple Silicon macOS using Rust bindings to Apple's Hypervisor framework.
+- [Rust: Memory safety in kernel space](https://oshub.org/users/OSHub/posts/rust-memory-safety-in-kernel-space-9178dd)
+  - An OS-focused introduction to how Rust's ownership and `unsafe` boundaries change kernel development.
 - [Bringing Rust to the Pixel Baseband](https://blog.google/security/bringing-rust-to-the-pixel-baseband/)
   - Google describes adding Rust to Pixel modem firmware, including `no_std` support for Hickory DNS dependencies, `core`/`alloc` integration, allocator and panic handler hooks, and firmware linking details.
 - [tinyboot v0.4.0 Released -- The API is Stable](https://aaronqian.com/log/2026-04-22-tinyboot-v040-released/)
   - A minimal Rust bootloader for resource-constrained MCUs. This release adds CH32V00x support, collapses the CH32 crates, stabilizes the wire protocol, and fixes half-duplex UART bugs.
-- [A minimal VMM in Rust with Apple Hypervisor](https://gigapotential.dev/blog/minimal-vmm-in-rust-with-apple-hypervisor/)
-  - Walks through building a small virtual machine monitor on Apple Silicon macOS using Rust bindings to Apple's Hypervisor framework.
-- [Rust: Memory safety in kernel space](https://oshub.org/users/OSHub/posts/rust-memory-safety-in-kernel-space-9178dd)
-  - An OS-focused introduction to what Rust's ownership and `unsafe` boundaries change for kernel development.
 - [Using Rust to Build a $1 Handheld Gaming Console](https://chrisdell.info/using-rust-to-build-a-1-dollar-handheld-gaming-console/)
   - A small embedded Rust project on the CH32V003 RISC-V microcontroller, with notes on RAM-constrained rendering and fixed-point math.
+- [Zero-copy pages in Rust](https://redixhumayun.github.io/databases/2026/04/14/zero-copy-pages-in-rust.html)
+  - Explores an approach for working with database pages in Rust while avoiding unnecessary copies.
+- [This Month in Redox - April 2026](https://www.redox-os.org/news/this-month-260430/)
+  - The Redox project reports updates across the kernel, system libraries, drivers, and userspace.
 
 ## Infrastructure and Tooling
 
@@ -67,14 +71,14 @@ In this section, we collect recent updates to `rustc`, `cargo`, and other toolin
 - [Rust 1.95.0](https://blog.rust-lang.org/2026/04/16/Rust-1.95.0/)
   - Stabilizes `cfg_select!`, atomic `update`/`try_update` methods, and allocator layout helpers such as `Layout::{dangling_ptr, repeat, repeat_packed, extend_packed}`.
   - Important for custom-target users: stable `rustc` no longer accepts JSON target specifications. Building `core` for custom targets still requires nightly-only features.
+- Move `std::io` pieces toward `core::io`
+  - [`ErrorKind`](https://github.com/rust-lang/rust/pull/154654) and [`RawOsError`](https://github.com/rust-lang/rust/pull/155574) were moved into `core::io`, continuing the groundwork for more I/O abstractions in `no_std` contexts.
 - [Add `-Zsanitize=kernel-hwaddress`](https://github.com/rust-lang/rust/pull/153049)
   - Adds nightly support for the kernel hardware address sanitizer mode used by Linux's `CONFIG_KASAN_SW_TAGS`.
 - [Mitigation enforcement RFC](https://github.com/rust-lang/rfcs/pull/3855)
-  - Approved RFC for tracking and enforcing target-wide exploit mitigation options such as stack protector settings.
+  - An approved RFC for tracking and enforcing target-wide exploit mitigation options such as stack protector settings.
 - [build-std: always RFC](https://github.com/rust-lang/rfcs/pull/3874)
   - Proposed Cargo configuration for rebuilding standard library crates, part of the ongoing effort to make `build-std` usable on stable.
-- Move `std::io` pieces toward `core::io`
-  - [`ErrorKind`](https://github.com/rust-lang/rust/pull/154654) and [`RawOsError`](https://github.com/rust-lang/rust/pull/155574) were moved into `core::io`, continuing the groundwork for more IO abstractions in `no_std` contexts.
 
 ## `rust-osdev` Projects
 
@@ -92,16 +96,28 @@ In this section, we give an overview of notable changes to the projects hosted u
     <<changelog, either in list or text form>>
 -->
 
+### [`pvh`](https://github.com/rust-osdev/pvh)
+<span class="maintainers">Maintained by [@mkroening](https://github.com/mkroening)</span>
+
+The `pvh` crate contains definitions for Xen's [x86/HVM direct boot ABI](https://xenbits.xen.org/docs/unstable/misc/pvh.html) (PVH). PVH is commonly used for direct kernel boot in virtual machine managers (VMMs), such as [QEMU](https://www.qemu.org), and in VMMs using the [`linux-loader`](https://github.com/rust-vmm/linux-loader) crate, such as [Firecracker](https://firecracker-microvm.github.io) and [Cloud Hypervisor](https://www.cloudhypervisor.org).
+
+The crate allows kernels to be booted via PVH and helps read the data provided via physical addresses. Its structures can also be used in VMMs or bootloaders to create appropriate start info structures when loading a kernel.
+
+The [new repository](https://github.com/rust-osdev/pvh) was created this month and is also available [on crates.io](https://crates.io/crates/pvh).
+
+Thanks to [@mkroening](https://github.com/mkroening) for creating the project!
+
+
 ### [`acpi`](https://github.com/rust-osdev/acpi)
 <span class="maintainers">Maintained by [@IsaacWoods](https://github.com/IsaacWoods)</span>
 
-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.
+The `acpi` repository contains crates for parsing the ACPI tables – data structures that the firmware of modern computers uses to relay information about the hardware to the OS.
 
 We merged the following changes this month:
 
 - [Support multiple tables per test in `aml_tester`](https://github.com/rust-osdev/acpi/pull/284)
 - [Implement Index and Bank fields](https://github.com/rust-osdev/acpi/pull/274)
-- [Add support for running the tests from uACPI.](https://github.com/rust-osdev/acpi/pull/285)
+- [Add support for running the tests from uACPI](https://github.com/rust-osdev/acpi/pull/285)
 - [Remove some AML-triggerable panics from library](https://github.com/rust-osdev/acpi/pull/276)
 - [Derive Clone, Debug on useful objects](https://github.com/rust-osdev/acpi/pull/287)
 - [(minor) Trace the table ID better](https://github.com/rust-osdev/acpi/pull/291)
@@ -139,24 +155,14 @@ Thanks to [@JarlEvanson](https://github.com/JarlEvanson) for their contributions
 
 The `bootloader` crate implements a custom Rust-based bootloader for easy loading of 64-bit ELF executables. This month, we merged the following change:
 
-- [Update to v0.11.15 and add missing x86_64-unknown-uefi target ](https://github.com/rust-osdev/bootloader/pull/557)
+- [Update to v0.11.15 and add missing x86_64-unknown-uefi target](https://github.com/rust-osdev/bootloader/pull/557)
 
 <!-- - [Bump rand from 0.8.5 to 0.8.6](https://github.com/rust-osdev/bootloader/pull/559) -->
 <!-- - [Bump rustls-webpki from 0.103.10 to 0.103.13 in /examples/basic](https://github.com/rust-osdev/bootloader/pull/560) -->
 
 Thanks to [@peppergrayxyz](https://github.com/peppergrayxyz) for their contribution!
 
 
-### [`linked-list-allocator`](https://github.com/rust-osdev/linked-list-allocator)
-<span class="maintainers">Maintained by [@phil-opp](https://github.com/phil-opp) and [@jamesmunns](https://github.com/jamesmunns)</span>
-
-The `linked-list-allocator` crate provides a basic `no_std` allocator that builds a linked list from freed memory blocks and thus needs no additional data structures. We merged the following PR this month:
-
-- [fix(alloc_ref): use renamed `dangling`](https://github.com/rust-osdev/linked-list-allocator/pull/90)
-
-Thanks to [@sermuns](https://github.com/sermuns) for their contribution!
-
-
 ### [`x86_64`](https://github.com/rust-osdev/x86_64)
 <span class="maintainers">Maintained by [@phil-opp](https://github.com/phil-opp), [@josephlr](https://github.com/orgs/rust-osdev/people/josephlr), and [@Freax13](https://github.com/orgs/rust-osdev/people/Freax13)</span>
 
@@ -166,6 +172,16 @@ We merged the following PR this month:
 
 - [insert NOP after STI](https://github.com/rust-osdev/x86_64/pull/588)
 
+
+### [`linked-list-allocator`](https://github.com/rust-osdev/linked-list-allocator)
+<span class="maintainers">Maintained by [@phil-opp](https://github.com/phil-opp) and [@jamesmunns](https://github.com/jamesmunns)</span>
+
+The `linked-list-allocator` crate provides a basic `no_std` allocator that builds a linked list from freed memory blocks and thus needs no additional data structures. We merged the following PR this month:
+
+- [fix(alloc_ref): use renamed `dangling`](https://github.com/rust-osdev/linked-list-allocator/pull/90)
+
+Thanks to [@sermuns](https://github.com/sermuns) for their contribution!
+
 ## Other Projects
 
 In this section, we describe updates to Rust OS 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.
@@ -188,14 +204,21 @@ Key features:
 
 - **S-EL2 SPMC**: Runs as BL32 in TF-A boot chain, replacing Hafnium. Manages multiple Secure Partitions (SPs) at S-EL1 with per-SP Secure Stage-2 page tables.
 - **FF-A v1.1**: Full proxy implementation including DIRECT_REQ/RESP messaging, memory sharing (MEM_SHARE/LEND/DONATE/RETRIEVE/RELINQUISH/RECLAIM), descriptor fragmentation, PARTITION_INFO_GET, notifications, indirect messaging, and CONSOLE_LOG.
-- **pKVM integration**: Coexists with Android pKVM at NS-EL2 — our SPMC at S-EL2, pKVM at NS-EL2. 35/35 `ffa_test.ko` tests pass including SP-to-SP DIRECT_REQ relay and SP-to-SP memory sharing through the real SPMD chain.
+- **pKVM integration**: Coexists with Android pKVM at NS-EL2 — our SPMC at S-EL2, pKVM at NS-EL2. 35/35 `ffa_test.ko` tests pass, including SP-to-SP DIRECT_REQ relay and SP-to-SP memory sharing through the real SPMD chain.
 - **Multi-VM**: 2 Linux VMs time-sliced with VMID-tagged TLBs and per-VM Stage-2 page tables.
 - **SMP**: Both 4-vCPU-on-1-pCPU (round-robin scheduler) and 4-vCPU-on-4-pCPU (1:1 affinity) modes.
 - **SP-to-SP**: CallStack cycle detection, recursive dispatch, chain preemption, secure virtual interrupt injection via HCR_EL2.VI.
 - **34 test suites** with ~457 assertions running on QEMU, plus 20/20 BL33 E2E integration tests.
 
 
+### [`MohammadMuzamil23/Qunix-Operating-System`](https://github.com/MohammadMuzamil23/Qunix-Operating-System)
+<span class="maintainers">(Section suggested by JustSmile)</span>
+
+Qunix is a Unix-like hobby operating system written in Rust. It includes a process model, virtual filesystem layer, memory management with COW fork and demand paging, an ELF loader, and a priority-based preemptive scheduler.
+
+The project recently reached userspace and is making progress on POSIX compatibility. Its initial `v0.2.0` release adds 70+ userland utilities, including a shell (`qsh`), along with blocking pipes, a TTY subsystem, and POSIX-style signal delivery.
+
 
 ## 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 [Zulip chat](https://rust-osdev.zulipchat.com).
+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 to get in touch is our [Zulip chat](https://rust-osdev.zulipchat.com).