Re: Is there a way to get the architecture of the machine just booted up by GRUB2: [32|64]-[amd|arm]? ...

[Pascal Hambourg]

On 18/12/2023 at 04:26, Andrei Borzenkov wrote:
> On 17.12.2023 23:50, Pascal Hambourg wrote:
> ...
> > Note 2: there have been a few lightweight PC with 32-bit UEFI firmware
> > and 64-bit x86 CPU around. To boot on these you need to install an x86
> > 32-bit EFI image as bootia32.efi. It can boot i386 and amd64 kernels.
> ...
> > if [ $grub_cpu = x86_64 ]; then
> >     # instructions to boot with amd64 kernel
> > elif [ $grub_cpu = i386 ]; then
> >     # instructions to boot with i386 kernel
>
> This obviously will not work for such systems as you mentioned earlier. 

64-bit CPUs can run 32-bit kernels, so it will work but be sub-optimal.
Or you can drop support for 32-bit CPUs and load a 64-bit kernel even 
with 32-bit UEFI. It seems that only early Intel Mac had 32-bit CPU and 
UEFI.

> Besides, distributions may require additional CPU features beyond mere 
> "supports 64 bit".

Do you mean 32-bit CPU features such as PAE ?