Date: Mon, 25 Nov 2013 19:49:02 +0700 From: Alexey Dokuchaev <danfe@nsu.ru> To: powerpc@freebsd.org Subject: mfpvr instruction: how to get processor version info from userland? Message-ID: <20131125124901.GA87016@regency.nsu.ru>
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hi there, i might soon have a chance to play with powerpc, so i'm wondering about few things about the arch and cpu; particularly, i'm wondering if there is something like cpuid instruction for intel. it seems that mfpvr should do the job, but it can only be called from kernel. Linux emulates it so user-space can have access to the info; but in FreeBSD, its prototype is hidden under #ifdef _KERNEL :( grep'ing -R mfpvr /sys/powerpc shows an interesting line in /sys/powerpc/aim/trap.c: frame->fixreg[reg] = mfpvr(); i haven't yet made my way through this code, but have a quick question: is there a way to obtain mfpvr() value from userland (thru kernel catching the trap that the processor raises when a non-privileged program tries to execute it), or i have to write my own kld for that? i also wonder why it was made privileged in the first place... thanks, ./danfe
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