Red Bear OS
4f2a0436eb
Phase A of the ACPI fork-sync plan (local/docs/ACPI-FORK-SYNC-STRATEGY-2026-06-30.md). Restores the kernel to the upstream Redox OS kernel main branch state for the ACPI subsystem: - Cargo.toml: switch redox_syscall from 0.7.4 (two versions behind) to a git ref of gitlab.redox-os.org/redox-os/syscall.git, matching the upstream master dependency. The crates.io 0.8.1 release predates the AcpiVerb enum that MR #613 / MR #275 introduced, so a crates.io pin is insufficient. - src/acpi/rsdp.rs: full rewrite to match upstream f49c7d99 (RSDP validation + NonNull + fail-softly): * signature check "RSD PTR " * 20-byte base checksum * full-length checksum for revision >= 2 * NonNull<u8> instead of *const u8 Fixes gap #1 from the 2026-06-30 ACPI assessment: the kernel was accepting any pointer from the bootloader without validation. - src/startup/mod.rs: acpi_rsdp() returns Option<NonNull<u8>> to match the new Rsdp::get_rsdp signature. - src/acpi/mod.rs: init() takes Option<NonNull<u8>>. - src/scheme/acpi.rs: full rewrite to upstream MR #613 (Simplify acpi scheme). Drops the /scheme/kernel.acpi/ filesystem surface in favor of a single Fd::open + call() interface with AcpiVerb verbs: * AcpiVerb::ReadRxsdt - returns the raw RXSDT bytes * AcpiVerb::CheckShutdown - returns whether shutdown is pending Uses HandleBits bitflags, atomic EXISTS_KSTOP_HANDLE, Mutex<L4> from crate::sync::ordered. Replaces /scheme/kernel.acpi/rxsdt and /scheme/kernel.acpi/kstop files. - src/scheme/mod.rs: KernelScheme::kcall signature updated to take fds: &[usize] instead of id: usize (matches upstream). kfpath now has a default body returning EOPNOTSUPP (matches upstream). - src/scheme/memory.rs, proc.rs, user.rs: kcall impls updated to match new trait signature, using fds.first() to extract the single handle for backward compat. - src/scheme/proc.rs: kcall dispatch adds _ => Err(EINVAL) catch-all for the new ProcSchemeVerb variants (RegsInt, RegsFloat, RegsEnv, SchedAffinity, Start) that the gitlab syscall crate adds. These verbs are not yet implemented in the proc scheme; the catch-all returns EINVAL cleanly instead of failing to compile. - src/syscall/fs.rs: SYS_CALL dispatcher now passes &[number] to scheme.kcall() to match the new trait signature. - Makefile: removed -Z json-target-spec flag (promoted to stable in nightly 2026-04-01; the flag is unknown in our pinned toolchain). Verified by `make` in local/sources/kernel/ with PATH including the prefix cross-toolchain: kernel builds and links successfully.
Kernel
Redox OS Microkernel
Requirements
nasmneeds to be available on the PATH at build time.
Building The Documentation
Use this command:
cargo doc --open --target x86_64-unknown-none
Debugging
QEMU
Running QEMU with the -s flag will set up QEMU to listen on port 1234 for a GDB client to connect to it. To debug the redox kernel run.
make qemu gdb=yes
This will start a virtual machine with and listen on port 1234 for a GDB or LLDB client.
GDB
If you are going to use GDB, run these commands to load debug symbols and connect to your running kernel:
(gdb) symbol-file build/kernel.sym
(gdb) target remote localhost:1234
LLDB
If you are going to use LLDB, run these commands to start debugging:
(lldb) target create -s build/kernel.sym build/kernel
(lldb) gdb-remote localhost:1234
After connecting to your kernel you can set some interesting breakpoints and continue
the process. See your debuggers man page for more information on useful commands to run.
Notes
-
Always use
foo.get(n)instead offoo[n]and try to cover for the possibility ofOption::None. Doing the regular way may work fine for applications, but never in the kernel. No possible panics should ever exist in kernel space, because then the whole OS would just stop working. -
If you receive a kernel panic in QEMU, use
pkill qemu-systemto kill the frozen QEMU process.
How To Contribute
To learn how to contribute to this system component you need to read the following document:
Development
To learn how to do development with this system component inside the Redox build system you need to read the Build System and Coding and Building pages.
How To Build
To build this system component you need to download the Redox build system, you can learn how to do it on the Building Redox page.
This is necessary because they only work with cross-compilation to a Redox virtual machine, but you can do some testing from Linux.
Funding - Unix-style Signals and Process Management
This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.
