Red Bear OS
2a3b0d4e0a
Implement the Linux 7.1 xhci.c:4650 xhci_set_usb2_hardware_lpm() enable
path, closing the P7-A gap on top of the P2-B substrate:
- usb/bos.rs: BosUsb2ExtDesc bmAttributes accessors (LPM support, BESL
support/validity, baseline/deep BESL fields) + 3 unit tests
- xhci/mod.rs:
- change_max_exit_latency(): MEL update via Evaluate Context (slot
output context copied, SLOT add flag, DWORD1 low 16 bits = MEL) —
Linux xhci.c:4520
- calculate_hird_besl(): HCS_PARAMS3 U2 latency + device BESL
attributes — Linux xhci.c:4594
- enable_usb2_hw_lpm(): BESL vs HIRD parameter selection, MEL
Evaluate Context, PORTHLPMC/PORTPMSC programming via the existing
Port::enable_lpm — Linux xhci.c:4686-4722
- BESL_ENCODING_US table, XHCI_L1_TIMEOUT_US=512, XHCI_DEFAULT_BESL=4
- xhci/scheme.rs (get_desc): attach-time gate chain — hw_lpm_support &&
per-port HLC (USB 2.0 protocol only) && device USB_LPM_SUPPORT in BOS
&& non-hub class && root-hub-direct (get_desc only runs for root-port
devices). LPM enable failure logs a warning and continues — LPM is
opportunistic; the device works in U0 regardless.
Verified: cargo check -Z build-std --target x86_64-unknown-redox -p
xhcid clean (no new warnings). Unit tests compile-verified; execution
requires redoxer like the crate's existing test suite. Runtime L1
entry validation requires LPM-capable hardware (QEMU's xHCI does not
advertise HLC) — recorded as hardware-validation debt in the USB plan.
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.