hdaudio-uefi

An attempt to port the RedoxOS HD Audio driver to pure Rust, with no standard library. Currently in progress towards basic first goal of nightly Rust for x86_64 UEFI, which has part of the standard library, then work to port that to no_std:

• x86_64-unknown-uefi (nightly, with std)
• x86_64-unknown-uefi (stable, no_std)
• x86_64-unknwon-unknown (no_std, stable, possibly no_alloc?)

TODO

• Re-implement original syscall::* interfaces from original redox-drivers repo.
  • syscall::physmap
  • syscall::physalloc
  • syscall::physfree
  • syscall::setrens
  • syscall::fmap
  • syscall::open
  • syscall::close

Running

• cd hdaudio
• cargo +nightly build --target x86_64-unknown-uefi
• cd ..
• ./qemu.sh
• once inside QEMU
• FS0:
• .\ihdad.efi

Current Problems

• Running on real hardware (Framework, Intel 11th Gen)
  • Program exists after returning from IntelHDA::configure()
  • I assume this is because something is overwriting a stack pointer or something?
  • Or maybe tthere's a bigger issue?
  • No leads so far.
  • Something interesting is that the capabilities register appears to show 0x0 on real hardware, so maybe that's related.

Previous Problems

• Could read, but not write values.
  • Fixed by using direct memory access instead of memory-mapped IO.
• Could not read updates to RIRBWP address (in QEMU).
  • Fixed in QEMU by adding the: -device ich9-intel-hda -device hda-duplex
• Random crashes
  • Fixed by removing syscall::* functions and replacing with std:: functions, where possible.
  • HashMap -> BTreeMap: HashMaps instantly crash the program.
• Leaving the HdaDevice::configure() function caused an instant crash.
  • This is confirmed as due to the drop(...) implementation of the path variable causing the crash. If the drop() is done early and explicitly, it crashes early.
  • It is not the Vec<_> or (u8, u16) drop impls that are causing this.... Is there a custom drop somewhere?
  • The value also appears to change midway through. Reading the value twice shows two different values [(0,0),(0,10)], then [(0,0),(0,0)] unsure what that is. Probably some memory magic I'm unaware of.
  • Unknown how to fix.