i386 registers during a syscall
attilio at freebsd.org
Sun Jul 23 21:18:59 UTC 2006
2006/7/23, Divacky Roman <xdivac02 at stud.fit.vutbr.cz>:
> I need to get content of %esi register as it was during a syscall. Should I get
> this info from td->td_pcb->pcb_esi or td->td_frame->tf_esi?
> Is it so that trapframe is "content of registers when entering a kernel" and
> pcb is "when leaving a kernel" ?
> thnx for info
pcb and trapframe are used for very different purposes.
The trapframe is built into the exception handler and it is used as
'registers gate' from userspace/kernelspace.
The pcb (process control block) is used to handle registers saving
during a context switch, so it seems completely ortogonal to your
BTW, it's unclear to me what do you need...
Peace can only be achieved by understanding - A. Einstein
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