Re: Troubles extending Ubuntu 22.04 ISO

[Thomas Schmitt]

Hi,

Ash Arnold wrote:
> I was able to start skipping the extraction step, which is where the
> conflicting eltorito.img came from. I wasn't actually wanting to replace it.

I have troubles to imagine a use case where one would want to replace
the Legacy BIOS boot image. That's why i never really tested this and
why the bug existed until 6 weeks ago.


> Writing to 'build/dex-autoinstall-22.04.4.iso' completed successfully.

Congrats.


> The issue I hit now is that even with this successful build, something about
> the ISO seems not-quite-right as the Ubuntu usb tool 'Startup Disk Creator'
> says the iso isn't a valid bootable iso and won't copy it to USB. Sadly it
> doesn't seem to offer any error message as to -why- it thinks this. I'm able
> to boot the iso fine in qemu. I haven't yet tested it out on bare metal.

I can make an own offer of (hopefully) safely copying an ISO to USB stick:

  https://wiki.debian.org/XorrisoDdTarget

Probably the script is meanwhile available as package "xorriso-dd-target"
in Ubuntu. In Debian it is available since version 12 ("stable" since a
year).
Above wiki text talks of Debian ISOs, but Ubuntu ISOs are prepared for
booting from USB stick too (as are most current distro ISOs).

I have read about problems booting modified Ubuntu ISOs because of
checksum files which would need to be updated. But if your ISO boots in
qemu from pseudo hard disk, then i don't expect it to make problems on
real iron from USB stick.


Have a nice day :)

Thomas