Date: Sun, 23 Jul 2006 23:18:56 +0200 From: "Attilio Rao" <attilio@freebsd.org> To: "Divacky Roman" <xdivac02@stud.fit.vutbr.cz> Cc: freebsd-hackers@freebsd.org Subject: Re: i386 registers during a syscall Message-ID: <3bbf2fe10607231418y58510d02ua208acbb44ea9f8c@mail.gmail.com> In-Reply-To: <20060723112332.GA83581@stud.fit.vutbr.cz> References: <20060723112332.GA83581@stud.fit.vutbr.cz>
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2006/7/23, Divacky Roman <xdivac02@stud.fit.vutbr.cz>: > hi, > > 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 problem. BTW, it's unclear to me what do you need... Attilio -- Peace can only be achieved by understanding - A. Einstein
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