Conversation
Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp>
Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp>
Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp>
There was a problem hiding this comment.
Pull request overview
This PR adjusts the x86bootdisk helper tool and build scripts to split BIOS vs UEFI boot image generation using Cargo features, with the goal of making x86_64 QEMU boot reliably by avoiding incompatible bootloader build paths.
Changes:
- Introduces
bios/uefifeature flags inx86bootdiskand gates bootloader usage accordingly. - Updates x86_64 Makefile image targets to build
x86bootdiskwith--no-default-featuresand the appropriate boot feature. - Removes
multilingual = falsefrom the mdBook configuration.
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.
| File | Description |
|---|---|
| x86bootdisk/src/main.rs | Feature-gates BIOS/UEFI boot paths and adjusts CLI defaulting behavior based on enabled features. |
| x86bootdisk/Cargo.toml | Adds bios/uefi features and disables bootloader default features to control build paths. |
| mdbook/book.toml | Simplifies mdBook config by removing the explicit multilingual setting. |
| Makefile | Builds BIOS and UEFI images by selecting the corresponding x86bootdisk feature set. |
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
| #[cfg(feature = "bios")] | ||
| use bootloader::BiosBoot; | ||
| #[cfg(feature = "uefi")] | ||
| use bootloader::UefiBoot; | ||
|
|
There was a problem hiding this comment.
With the new feature-gated enum variants and Default impl, building this crate with --no-default-features and without selecting either bios or uefi will fail with confusing compiler errors (e.g., missing Default::default impl items / empty BootType). Consider adding an explicit #[cfg(not(any(feature = "bios", feature = "uefi")))] compile_error!(...) guard so misconfigured builds fail with a clear message.
There was a problem hiding this comment.
@copilot apply changes based on this feedback
There was a problem hiding this comment.
Added a compile_error! guard in commit d69ffdc so that builds with --no-default-features and neither bios nor uefi selected will fail with a clear message:
#[cfg(not(any(feature = "bios", feature = "uefi")))]
compile_error!("At least one of the `bios` or `uefi` features must be enabled.");| [features] | ||
| default = ["bios", "uefi"] | ||
| bios = ["bootloader/bios"] | ||
| uefi = ["bootloader/uefi"] |
There was a problem hiding this comment.
The PR description suggests isolating BIOS vs UEFI via Cargo features to avoid problematic build paths, but default = ["bios", "uefi"] still enables (and compiles) both by default. If the intent is to avoid BIOS-related build failures unless explicitly requested, consider making the default feature set [] or ['uefi'] and requiring callers (e.g., the Makefile) to opt into bios explicitly.
|
|
||
| x86_64_boot.img: kernel-x86_64.elf | ||
| RUSTFLAGS="$(RUSTC_MISC_ARGS)" cargo +$(RUSTV) run --release --package x86bootdisk -- --kernel $< --output $@ | ||
| RUSTFLAGS="$(RUSTC_MISC_ARGS)" cargo +$(RUSTV) run --release --package x86bootdisk --no-default-features --features bios -- --kernel $< --output $@ |
There was a problem hiding this comment.
This target now relies on BootType's CLI default to select BIOS (since --boot-type bios is not passed). To make the build resilient to future changes in the Rust-side defaulting logic (or feature defaults), consider passing --boot-type bios explicitly here, similar to the UEFI target.
| RUSTFLAGS="$(RUSTC_MISC_ARGS)" cargo +$(RUSTV) run --release --package x86bootdisk --no-default-features --features bios -- --kernel $< --output $@ | |
| RUSTFLAGS="$(RUSTC_MISC_ARGS)" cargo +$(RUSTV) run --release --package x86bootdisk --no-default-features --features bios -- --kernel $< --output $@ --boot-type bios |
…abled Agent-Logs-Url: https://github.com/tier4/awkernel/sessions/ee6a4be0-5fde-4c35-98e0-5c7ccceb9941 Co-authored-by: nokosaaan <106376734+nokosaaan@users.noreply.github.com>
Description
I fixed an issue where QEMU on x86_64 would not start properly.
This was resolved by clearly separating the BIOS and UEFI boot paths using the
featuresoption.With the current configuration, the build process generated numerous warnings and errors,
preventing the program from starting successfully.
Specifically, the error
error: unknown -Z flag specified: json-target-specwas being displayed.The
-Zflag is used to specify unstable, experimental features of the Rust compiler. It appears the issue arose because an outdated or incompatible version of Rust Nightly was used during the build of the Bootloader package, causing the flag to go unrecognized.Possible solutions include:
The nightly build is already the latest version, and the Bootloader is also kept up to date. Since we confirmed that it works without issues when using a compatible version, rolling back the version would be preferable; however, the cost of rework and the impact on existing code are significant, making this impractical.
Therefore, since the BIOS processing is not expected to run in the current implementation, I isolated it in
features. After confirming that it behaves the same as the compatible version, we decided to implement this fix.In addition, a
compile_error!guard was added tox86bootdisk/src/main.rsto produce a clear, actionable compiler error when the crate is built with--no-default-featuresand neither thebiosnoruefifeature is selected, preventing confusing missing-impl errors in misconfigured builds.Related links
https://github.com/rust-osdev/bootloader
How was this PR tested?
Please refer to attached files.
Compile logs are showed.
bootloader-fix.log
main.log
Notes for reviewers