mjg:
> > Some especially creative BIOS authors[5] have decided that users
> > shouldn't have their choices limited in such a way, and so pop up
> > a screen that says:
> > 1. 2. Select CD-ROM boot type:
So it might be worth a try to repack the Ubuntu ISO so that it
only offers the El Torito EFI boot image.
Regrettably Ubuntu does not publish the used xorriso -as mkisofs
options. (Debian has them in /.disk/mkisofs.)
So one would have to guess:
# Mount existing ISO
mount -o loop mini.iso /mnt
# Use the mounted file tree to build a new ISO
xorriso -as mkisofs \
-o eltorito_efi_only.iso \
-r -V "CDROM" \
-c boot.cat \
-e boot/grub/efi.img -no-emul-boot \
/mnt
The result will not boot via BIOS and not from USB stick.
Let's see what it bears ... (962 MB gives enough time to cook a tea) ...
Surprise. It's BIOS only:
Boot record : El Torito , ISOLINUX isohybrid MBR pointing to boot image
Boot catalog : '/isolinux/boot.cat'
Boot image : '/isolinux/isolinux.bin' , boot_info_table=on
TOC layout : Idx , sbsector , Size , Volume Id
ISO session : 1 , 0 , 492544s , Ubuntu 14.04 LTS amd64
There is an MBR partition table with partition start at 32 KB
and a second ISO superblock matching that offset (caused by
xorriso -as mkisofs option -partition_offset 16).
The isohybrid MBR could be extracted by
dd if=trusty-desktop-amd64+mac.iso bs=512 count=1 of=isohybrid.mbr
and brought into effect when repacking, by option
-isohybrid-mbr isohybrid.mbr \
Now i wonder why an "amd64+mac" image is offering only the two
boot paths for PC-BIOS firmware.
It would be really interesting to see whether an EFI-only repack
of the "regular" amd64 ISO.
(Which URL would that be, btw ?)
Do not forget to adjust the -V text in above example to the Volume Id
of the original ISO. Many systems get stuck after kernel booting if
the Volume Id is not as expected.
> Preparer Id : XORRISO-1.2.4 2012.07.20.130001, LIBISOBURN-1.2.4, LIBISOFS-1.2.4, LIBBURN-1.2.4
(There are newer versions of xorriso around. With fresher bugs.)
Hi,
> http:// mjg59.dreamwidt h.org/4957. html
Yeah ... booting is a multifarious endeavor.
mjg:
> > Some especially creative BIOS authors[5] have decided that users
> > shouldn't have their choices limited in such a way, and so pop up
> > a screen that says:
> > 1. 2. Select CD-ROM boot type:
So it might be worth a try to repack the Ubuntu ISO so that it
only offers the El Torito EFI boot image.
Regrettably Ubuntu does not publish the used xorriso -as mkisofs
options. (Debian has them in /.disk/mkisofs.)
So one would have to guess:
# Mount existing ISO
mount -o loop mini.iso /mnt
# Use the mounted file tree to build a new ISO efi_only. iso \
xorriso -as mkisofs \
-o eltorito_
-r -V "CDROM" \
-c boot.cat \
-e boot/grub/efi.img -no-emul-boot \
/mnt
The result will not boot via BIOS and not from USB stick.
EL Torito BIOS only would be:
xorriso -as mkisofs \ bios_only. iso \
-no-emul- boot -boot-load-size 4 -boot-info-table \
-o eltorito_
-r -V "CDROM" \
-c boot.cat \
-b isolinux.bin \
/mnt
The Volume ID "CDROM" and the paths of El Torito boot images and catalog
have been inquired by
xorriso -indev mini.iso -toc
which reports for mine grub/efi. img' , platform_id=0xEF
...
Boot catalog : '/boot.cat'
Boot image : '/isolinux.bin' , boot_info_table=on
Boot image : '/boot/
TOC layout : Idx , sbsector , Size , Volume Id
ISO session : 1 , 0 , 14879s , CDROM
...
Sebastian Bush: cdimage. ubuntu. com/daily- live/current/ trusty- desktop- amd64+mac. iso
> The ISO that works is
> http://
Let's see what it bears ... (962 MB gives enough time to cook a tea) ...
Surprise. It's BIOS only:
Boot record : El Torito , ISOLINUX isohybrid MBR pointing to boot image boot.cat' isolinux. bin' , boot_info_table=on
Boot catalog : '/isolinux/
Boot image : '/isolinux/
TOC layout : Idx , sbsector , Size , Volume Id
ISO session : 1 , 0 , 492544s , Ubuntu 14.04 LTS amd64
There is an MBR partition table with partition start at 32 KB
and a second ISO superblock matching that offset (caused by
xorriso -as mkisofs option -partition_offset 16).
The isohybrid MBR could be extracted by desktop- amd64+mac. iso bs=512 count=1 of=isohybrid.mbr
dd if=trusty-
and brought into effect when repacking, by option
-isohybrid-mbr isohybrid.mbr \
Now i wonder why an "amd64+mac" image is offering only the two
boot paths for PC-BIOS firmware.
It would be really interesting to see whether an EFI-only repack
of the "regular" amd64 ISO.
(Which URL would that be, btw ?)
Do not forget to adjust the -V text in above example to the Volume Id
of the original ISO. Many systems get stuck after kernel booting if
the Volume Id is not as expected.
> Preparer Id : XORRISO-1.2.4 2012.07.20.130001, LIBISOBURN-1.2.4, LIBISOFS-1.2.4, LIBBURN-1.2.4
(There are newer versions of xorriso around. With fresher bugs.)
Have a nice day :)
Thomas