Update xorriso paramters for 22.04 about live-custom-ubuntu-from-scratch

[kgilmer]

Thanks @piexil , I will certainly take a look at this for the next regolith ISO release

[kgilmer]

After blindly copy/pasting got the following error (regolith ISO generation):

 xorriso 1.5.4 : RockRidge filesystem manipulator, libburnia project.

Drive current: -outdev 'stdio:/home/runner/work/regolith-ubuntu-iso-builder/regolith-ubuntu-iso-builder/scripts/Regolith.iso'
Media current: stdio file, overwriteable
Media status : is blank
Media summary: 0 sessions, 0 data blocks, 0 data, 29.6g free
xorriso : WARNING : -volid text does not comply to ISO 9660 / ECMA 119 rules
Added to ISO image: directory '/'='/home/runner/work/regolith-ubuntu-iso-builder/regolith-ubuntu-iso-builder/scripts/image'
xorriso : UPDATE :      19 files added in 1 seconds
libisofs: FAILURE : Cannot find directory for El Torito boot catalog in ISO image: '/boot/grub'
libisofs: FAILURE : A requested node does not exist
xorriso : FAILURE : Could not attach El-Torito boot image to ISO 9660 image
xorriso : UPDATE :      19 files added in 1 seconds
xorriso : aborting : -abort_on 'FAILURE' encountered 'FAILURE'

[piexil]

@kgilmer
I think it's because the classic bios boot files need to be generated. The given parameter's are how most similar to how modern (>21.10) ubuntu builds their hybrid image.
As I said my project is different so this won't be exact copy-paste to this one, but here's the aprt of my scripts that generates the grub images and makes an ISO.

# # generate grub images
working_dir="$(pwd)"
cd "$iso_rw"

#grub uefi
grub-mkstandalone \
   --format=x86_64-efi \
   --output=isolinux/bootx64.efi \
   --modules="part_gpt part_msdos" \
   --locales="" \
   --fonts="" \
   "boot/grub/grub.cfg=isolinux/grub.cfg"

#fat16 uefi disk image containing bootloader
(
   cd isolinux &&
      dd if=/dev/zero of=efiboot.img bs=1M count=10 &&
      sudo mkfs.vfat efiboot.img &&
      LC_CTYPE=C mmd -i efiboot.img EFI EFI/BOOT &&
      LC_CTYPE=C mcopy -i efiboot.img ./bootx64.efi ::EFI/BOOT/
)

#grub bios images
grub-mkstandalone \
   --format=i386-pc \
   --output=isolinux/core.img \
   --install-modules="linux16 linux normal iso9660 biosdisk memdisk search tar ls" \
   --modules="linux16 linux normal iso9660 biosdisk search" \
   --locales="" \
   --fonts="" \
   "boot/grub/grub.cfg=isolinux/grub.cfg"

#combine
cat /usr/lib/grub/i386-pc/cdboot.img isolinux/core.img >isolinux/bios.img

# some broken UEFIs wont boot unless I do this
cp isolinux/efiboot.img EFI/BOOT/efiboot.img
cp isolinux/bios.img boot/grub/bios.img
cp isolinux/bootx64.efi EFI/BOOT/BOOTx64.EFI
cd "$working_dir"
LC_CTYPE=C mcopy -i ${iso_rw}/isolinux/efiboot.img -s ::EFI/ ${iso_rw}/EFI

# set seed files
cp installer/ubiquity/preseed/* "${iso_rw}/preseed/" || true

# this file will tell grub to look here
touch ${iso_rw}/$OS_NAME

# Regenerate the md5sum over the ISO contents.
working_dir="$(pwd)"
cd "$iso_rw"
rm md5sum.txt || true

/bin/bash -c "(find . -type f -print0 | xargs -0 md5sum | grep -v -e 'md5sum.txt' -e 'bios.img' -e 'efiboot.img' > md5sum.txt)"
cd "$working_dir"
working_dir="$(pwd)"
cd "$iso_rw"
# Create the ISO.
   xorriso -as mkisofs -r \
  -volid "${image_name}" \
  -full-iso9660-filenames \
  -J -J -joliet-long \
  -output "../$output_name" \
  --grub2-mbr /usr/lib/grub/i386-pc/boot_hybrid.img \
  -partition_offset 16 \
  --mbr-force-bootable \
  -append_partition 2 28732ac11ff8d211ba4b00a0c93ec93b isolinux/efiboot.img \
  -appended_part_as_gpt \
  -iso_mbr_part_type a2a0d0ebe5b9334487c068b6b72699c7 \
  -eltorito-boot isolinux/bios.img \
   -no-emul-boot \
   -boot-load-size 4 \
   -boot-info-table \
   --eltorito-catalog boot/grub/boot.cat \
   --grub2-boot-info \
  -eltorito-alt-boot \
  -e '--interval:appended_partition_2:::' \
    -no-emul-boot \
  "../${iso_rw}"

cd "$working_dir"

[kgilmer]

Thanks for the additional details @piexil . I am unable to determine what the following paths are set to in your setup as they don't exist in the mvallim repo:

working_dir
iso_rw

I looked for a fork of yours to see the diff but didn't see one listed on the github forks page. LMK if I missed it. TIA

[yveszoundi]

@kgilmer, I was able to following closely notes from piexil without much effort and I'm now able to use only Grub for both BIOS/Legacy and UEFI boot modes (in my own project, unrelated to this one and for a Debian-based Live CD).

Answers to your questions

• working_dir is just the parent directory from where all the commands get executed
  • You might have noticed that there are few "cd" commands implying a certain folder structure ("isolinux" folder, etc.)
  • In my own project, I try to always use absolute paths, unless a relative path is required by programs (xorriso)
• iso_rw would be the directory containing all the files that will end up on the Live CD in layman terms

Other notes

• For the part "this file will tell grub to look here", you can just use labels in your grub.cfg and skip that part
  • The label needs to match the volume ID specified in the xorriso command "-volid" (i.e. -volid REGOLITH_LIVECD)
  • The label in question would be in the grub.cfg file (i.e. search --set=root --label REGOLITH_LIVECD)
• For the part "some broken UEFIs wont boot unless I do this", I personally don't think that it's absolutely required
  • My approach is just to capitalize EFI related files and folders
  • I believe is what most UEFI implementations assume capitalized files and folders names.

Example

This is not meant for a "blind copy paste", but to better understand what you might need for "regolith" specifically.

Scripted step resulting in the ISO image creation for my application called Entrusted