Messages in this thread | | | Date | Mon, 9 Jun 2014 14:18:54 +0100 | Subject | Re: [PATCH] x86/boot: EFI_MIXED should not prohibit loading above 4G | From | Matt Fleming <> |
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On 9 June 2014 13:54, Vivek Goyal <vgoyal@redhat.com> wrote: > Hi Matt, > > So with new kexec syscall I have written 64bit bzImage loader. For now > I would like to detect this situation and disable loading and once > 32bit loader gets implemented it can take care of loading bzImage below > 4G.
What situation do you want to detect? You want to detect when it's impossible to load a kernel above 4G in the kexec path because you're booting with 32-bit EFI firmware?
> So how do I find out if EFI is 32bit.
efi_enabled(EFI_64BIT) will tell you that, but you probably also want to check that EFI runtime services are actually usable with efi_enabled(EFI_RUNTIME_SERVICES) since if they're not, you'll never call into the firmware so it doesn't matter where you load the kernel (this may happen with "noefi" kernel parameter).
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