Re: [PATCH] Change "efi" to "EFI" in grub-mkrescue for secure boot

[adrian15sgd]

El 14/9/24 a las 13:04, Askar Safin via Grub-devel escribió:
>   ---- On Wed, 11 Sep 2024 14:38:31 +0400  Tobias Powalowski via Grub-devel  
> wrote ---
>   > I was not able to use virtualbox on my project until I put the kernel
>   > also to the ISO fs I think,
>
> I suspect this is exactly same behaviour I'm talking about in my first letter. It is 
> behaviour called "GRUB searches for files in ISO fs when booted from CD (in UEFI 
> mode) and in ESP when booted from USB stick (in UEFI mode)". You seem to connect 
> .iso to virtualbox as virtual CD as opposed to virtual USB stick. This is simply how GRUB 
> works. This is exactly behaviour discussed in these letters in this thread:
> - 
> 20240906132914.27842-1-safinaskar@zohomail.com/">https://lore.kernel.org/grub-devel/20240906132914.27842-1-safinaskar@zohomail.com/
> - 
> 85fba0d5-de51-4736-9252-13576664cbc2@plouf.fr.eu.org/">https://lore.kernel.org/grub-devel/85fba0d5-de51-4736-9252-13576664cbc2@plouf.fr.eu.org/
> - 
> 29963309928969934189@scdbackup.webframe.org/">https://lore.kernel.org/grub-devel/29963309928969934189@scdbackup.webframe.org/
> - 
> bcd9e556-9fe7-46ac-bc6f-68225b0fe444@plouf.fr.eu.org/">https://lore.kernel.org/grub-devel/bcd9e556-9fe7-46ac-bc6f-68225b0fe444@plouf.fr.eu.org/
>
> And this behaviour was surprise to author of xorriso. Anyway I would not call 
> it a bug.

> GRUB searches for files in ISO fs when booted from CD (in UEFI mode)

Well, that needs more detailed explanation. There are two steps involved.
A Debian live cd as you have pointed out reuses a gcdx64.efi file.
That gcdx64.efi file has an embedded memdisk with an special grub.cfg. 
Then that special grub.cfg finds those CD files and configfiles to there.

As I want to be able to read the ElTorito image contents somehow I am 
actually trying to build a barebones Grub ElTorito image for UEFI CD 
boot in my Rescatux development streams.
I want to check what actually happens in that scenario without an 
embedded memdisk.

adrian15