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-
