2021-02-21 21:25:03

by Paul Menzel

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Subject: *Wrong EFI loader signature.* logged on non-EFI boot

Dear Linux folks,


Linux built with the attached config and `ARCH=i386`, and booted over
GRUB (coreboot payload or UEFI/CSM in MBR) logs the message below. The
message is visible on the monitor, and on serial only with `earlyprintk`.

```
Wrong EFI loader signature.
early console in extract_kernel
input_data: 0x016d90aa
input_len: 0x007472dc
output: 0x01000000
output_len: 0x00d5dad4
kernel_total_size: 0x00e3d000
needed_size: 0x00e3d000
Physical KASLR using RDTSC...

Decompressing Linux... Parsing ELF... Performing relocations... done.
Booting the kernel.
[ 0.000000] Linux version 5.11.0+ (root@b0f6de04e878) (gcc (Debian
10.2.1-3) 10.2.1 20201224, GNU ld (GNU Binutils for Debian) 2.35.1) #268
SMP Mon Feb 15 06:29:12 UTC 2021
[…]
```

It’s unexpected to see the EFI loader signature to be checked in this
scenario.


Kind regards,

Paul


Attachments:
config (111.67 kB)

2021-02-21 22:12:24

by Borislav Petkov

[permalink] [raw]
Subject: Re: *Wrong EFI loader signature.* logged on non-EFI boot

On Sun, Feb 21, 2021 at 10:22:56PM +0100, Paul Menzel wrote:
> It’s unexpected to see the EFI loader signature to be checked in this
> scenario.

Why is it unexpected? You have enabled that check through CONFIG_EFI=y.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette