[anarcat]

This is rather silly, but I keep forgetting how to format a disk just so. Having it built into grml2usb would be the best, but the next best thing is having an example in the manual.

This was tested on a Framework 12 laptop running UEFI.

[mika]

Great, thanks - ping @zeha :)

[mika]

Lovely, thanks!

[zeha]

I dunno about the esp on part, but if it works lets do it.

[anarcat]

I dunno about the esp on part, but if it works lets do it.

it's necessary for the disk to boot on a UEFI system. on my Framework 12, it wouldn't even detect the drive as bootable without that flag.

the real question is whether set boot on is required, because grub gives me all sorts of warnings about MBR when i follow those two commands. so it's possible legacy doesn't work and set boot on is the one that doesn't do anything!

[anarcat]

it's necessary for the disk to boot on a UEFI system. on my Framework 12, it wouldn't even detect the drive as bootable without that flag.

looks like i was wrong about this. i've been struggling to find a full grml2usb invocation that builds a thumb drive that the FW12 actually boots, the stuff I documented here doesn't actually work on this thumb drive.

so it's either a faulty thumb drive, or the instructions here are wrong. but the thumbdrive is good, because it does boot when i flash it with:

dd bs=4M status=progress conv=fdatasync if=grml-full-2026.09-amd64.iso of=/dev/sda

here are the two commands I ran:

parted /dev/sda --script mklabel gpt mkpart P1 fat32 0 100% set 1 boot on set 1 esp on
grml2usb --format grml-full-2026.09-amd64.iso /dev/sda1

i also tried:

grml2usb --format --bootloader=syslinux grml-full-2026.09-amd64.iso /dev/sda1
grml2usb --format --skip-mbr grml-full-2026.09-amd64.iso /dev/sda1
grml2usb --format --bootloader=efi grml-full-2026.09-amd64.iso /dev/sda1

none of those boot.

[mika]

@anarcat ah, just noticed that one tricky issue I also stumbled upon is that a dd-ed ISO leaves ISO9660/GPT stuff behind :-/ So make sure to wipe old signatures (e.g. wipefs -a /dev/sda), before using grml2usb.

What about:

parted /dev/sda --script mklabel msdos mkpart primary fat32 1MiB 100% set 1 boot on
grml2usb --verbose --format grml-full-2026.09-amd64.iso /dev/sda1

Does this work for you then? 🤔

[anarcat]

that shows up in the bootloard, but failed to boot:

error: invalid arch-independent ELF magic
Unknown command `normal`.
E: Could not find root device (for /conf/bootfile_grmlfullamd64_...)
error: invalid archi-indenendent ELF magic.
grub rescue>

copied by hand, might be typos.

[anarcat]

@anarcat ah, just noticed that one tricky issue I also stumbled upon is that a dd-ed ISO leaves ISO9660/GPT stuff behind :-/ So make sure to wipe old signatures (e.g. wipefs -a /dev/sda), before using grml2usb.

THAT ACTUALLY WORKED!

should we add the wipefs step here?