Red Bear OS 9c571e2942 pcid: guard config access against out-of-range offsets (fixes boot panic)
An extended-capability walk (pci_types capabilities()) that follows a
chain running to/past the end of config space read at offset 4096,
which tripped the dword-offset assert in bus_addr_offset_in_dwords
("pcie offset larger than 4095") and aborted pcid with an Invalid
opcode fault / UNHANDLED EXCEPTION on boot — after switchroot to /usr,
so it blocked reaching login.

PCIe config space is exactly 4096 bytes (offsets 0..=4095). Fix at two
levels:

- ConfigRegionAccess::read/write (cfg_access/mod.rs): guard the single
  access choke point — an out-of-range read returns the PCI "no
  response" pattern (0xFFFFFFFF, which also terminates a capability
  walk cleanly) and an out-of-range write is a no-op. This catches any
  caller (capability walk, scheme reads, driver access).

- scheme.rs config read/write loop: clamp the loop bound with
  saturating_add(...).min(4096) so a consumer requesting offset+len
  past the boundary reads only the valid part instead of looping to
  offset 4096.

Verified: boot no longer panics in pcid (progresses past the previous
crash point through switchroot and the /usr driver set).
2026-07-22 14:20:57 +09:00
2025-11-29 19:04:06 +01:00
2025-11-29 19:04:06 +01:00

Base

Repository containing various system daemons, that are considered fundamental for the OS.

You can see what each component does in the following list:

  • audiod : Daemon used to process the sound drivers audio
  • bootstrap : First code that the kernel executes, responsible for spawning the init daemon
  • daemon : Redox daemon library
  • drivers
  • init : Daemon used to start most system components and programs
  • initfs : Filesystem with the necessary system components to run RedoxFS
  • ipcd : Daemon used for inter-process communication
  • logd : Daemon used to log system components and daemons
  • netstack : Daemon used for networking
  • ptyd : Daemon used for pseudo-terminal
  • ramfs : RAM filesystem
  • randd : Daemon used for random number generation
  • zerod : Daemon used to discard all writes and fill read buffers with zero

How To Contribute

To learn how to contribute you need to read the following document:

If you want to contribute to drivers read its README

Development

To learn how to do development with these system components inside the Redox build system you need to read the Build System and Coding and Building pages.

How To Build

It is recommended to build this system component via the Redox build system, you can learn how to do it on the Building Redox page.

To build and test outside the build system, install redoxer then use check.sh script to build or test:

  • ./check.sh - Check build for x86_64
  • ./check.sh --arch=ARCH - Check build for specific ARCH (aarch64, i586, riscv64gc)
  • ./check.sh --all - Check build for all ARCH
  • ./check.sh --test - Check the base system boots up on x86_64

You can also use make install to inspect the content on ./sysroot, or make test-gui to test booting with orbital interactively.

S
Description
RedBear Operating System, based on RedoxOS. Licenced under MIT license.
https://redbearos.org
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