Messages in this thread | | | Date | Wed, 20 Jun 2012 16:48:37 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 2/2] x86, microcode: Make reload interface per system |
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On 06/20/2012 04:46 PM, Borislav Petkov wrote: >> >> Except you still need to re-poke it when you have a new microcode >> blob... so what was gained by all this churn? > > We need to do that anyway if new (F,M,S) ucode piece comes along. > > The gain is twofold: > > * we don't need the userspace tool to split the blob - we have one > single file we load and the driver picks out what it needs. > > * as a result, we drop the CONFIG_MICROCODE_OLD_INTERFACE, i.e. > /dev/cpu/microcode which takes the single blob anyway which the driver > picks apart later. > > In the end, we have one unified ucode loading procedure: > > 1. put the blob in /lib/firmware/... > 2. echo 1 > /sys/devices/system/cpu/microcode/reload > > That's it - it can't be simpler than that. >
I really don't get why the whole thing is any simpler than the old /dev/cpu/microcode interface in the first place, where instead of:
> 1. put the blob in /lib/firmware/... > 2. echo 1 > /sys/devices/system/cpu/microcode/reload
... you do ...
1. dd if=<microcode blob> of=/dev/cpu/microcode bs=<large>
... as well as set up the early initramfs part, of course.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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