Hi Kyrill,
> + if (!(hwcap & HWCAP_CPUID))
> + return false;
> +
> + unsigned long midr;
> + asm volatile ("mrs %0, midr_el1" : "=r" (midr));
> From what I recall that midr_el1 register is emulated by the kernel and so
> userspace software
> has to check that the kernel supports that emulation through hwcaps before
> reading it.
> According to
> https://www.kernel.org/doc/html/v5.8/arm64/cpu-feature-registers.html you
> need to check getauxval(AT_HWCAP) & HWCAP_CPUID) before doing that read.
That's why I do that immediately before reading midr_el1 - see above.
Cheers,
Wilco
