HelenOS sources

root/kernel/arch/ia32/include/arch/

[..]
arch.h asm.h bios/ boot/ context.h
context_struct.h cpu.h cpuid.h cycle.h ddi/
drivers/ faddr.h fpu_context.h interrupt.h istate.h
istate_struct.h mm/ pm.h proc/ smp/
stack.h syscall.h types.h vreg.h
[..]
HelenOS homepage, sources at GitHub