which tells the firmware that the I/O APIC is used rather than the 8259
PIC.

Replace Arc<Box<dyn Scheme>> with Arc<dyn Scheme>.

See merge request !116

Extend the IRQ scheme to allow allocation of all available interrupt vectors.

See merge request !115

I haven't been able to receive xhc interrupt anyway.

Fix warnings

See merge request redox-os/kernel!114

Update README's debugging instructions

See merge request !113

Fix deadlock in sys: scheme

See merge request !112

This patch fixes a deadlock in the sys: scheme that is triggered
when the iostat resource() is called in the same scope where the RwLock
protecting the scheme's handles is write-locked.