Georgi Naplatanov wrote:
Hi all!
I've just read Debian's Wiki page about CPU Microcode and there are
mentioned Intel's and AMD's processors for AMD64 architecture.
What is the situation with processors from other architectures
(arm64/AArch64 for example)?
- do they have microcode?
- can microcode be updated for these processors (from different
architectures) by Linux kernel? Is this supported by Debian GNU/Linux?
Microcode is run by a CPU to translate the nominal instruction
set (some variant on x86-64, for example) to the actually
implemented instruction set.
The majority of RISC-style CPUs don't have a microcode layer
because the point of RISC is that the CPU's native instruction
set is minimized -- the opinion is that compilers should do more
work.
What all CPUs have is errata -- mistakes that were made and
caught. If they are fixable, they are fixed in microcode for
machines that have that, or in the kernel for machines that
don't.
If you search for ARM_ERRATA in
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/Kconfig
you will see a number of situations in which the kernel is
fixing things that would otherwise be fixed in microcode.
So, upgrading the kernel is your best bet for those devices.
-dsr-