Re: [Bug-xorriso] Acer Aspire V5-121 doesn't see USB ISO as bootable

[Carlo Caione]

On Fri, Feb 17, 2017 at 1:12 PM, Thomas Schmitt <address@hidden> wrote:
> Hi,
>
> any new insight in this riddle ?

Hey Thomas,
Ok, so apparently we have found something interesting (and fixed the
issue at the same time).
BTW we had two different platforms affected by this problem: an Acer
Aspire V5-121 and a Dell series 7000.

As you know the _non-working_ endless image is:

xorriso : NOTE : Loading ISO image tree from LBA 0
xorriso : UPDATE : 300 nodes read in 1 seconds
libisofs: WARNING : Found hidden El-Torito image. Its size could not
be figured out, so image modify or boot image patching may lead to bad
results.
xorriso : NOTE : Detected El-Torito boot information which currently
is set to be discarded
Drive current: -indev 'eos-master-amd64-amd64.170209-111324.base.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record  : El Torito , MBR grub2-mbr cyl-align-off
Media summary: 1 session, 1062198 data blocks, 2075m data,  107g free
Volume id    : 'Endless-OS-3-1-0-base'
El Torito catalog  : 80  1
El Torito cat path : /boot.catalog
El Torito images   :   N  Pltf  B   Emul  Ld_seg  Hdpt  Ldsiz         LBA
El Torito boot img :   1  BIOS  y   none  0x0000  0x00      4     1059972
El Torito boot img :   2  UEFI  y   none  0x0000  0x00  18432     1062198
El Torito img path :   1  /endless/grub/i386-pc/iso/eltorito.img
El Torito img opts :   1  boot-info-table grub2-boot-info
El Torito img blks :   2  4608
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off
ISO image size/512 : 4248792
Partition offset   : 0
MBR heads per cyl  : 0
MBR secs per head  : 0
MBR partition table:   N Status  Type        Start       Blocks
MBR partition      :   1   0x80  0x83            0      4248792
MBR partition      :   2   0x00  0xef      4248792        18432

generated by:

xorriso -as mkisofs
-o ${OUTPUT}
-r -graft-points -no-pad --sort-weight 0 / --sort-weight 1 /endless
--grub2-mbr .../boot_hybrid.img
-append_partition 2 0xef .../efi.img
-b .../eltorito.img -no-emul-boot -boot-load-size 4 -boot-info-table
--grub2-boot-info -eltorito-alt-boot
-e --interval:appended_partition_2:all:: -no-emul-boot
-iso-level 3 ${DIR_IMAGES}

We were able to generate a _working_ image like this:

xorriso 1.4.4 : RockRidge filesystem manipulator, libburnia project.

xorriso : NOTE : Loading ISO image tree from LBA 0
xorriso : UPDATE : 300 nodes read in 1 seconds
xorriso : NOTE : Detected El-Torito boot information which currently
is set to be discarded
Drive current: -indev 'image.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record  : El Torito , MBR grub2-mbr cyl-align-off
Media summary: 1 session, 1063407 data blocks, 2077m data, 8695m free
Volume id    : 'Endless-OS'
El Torito catalog  : 80  1
El Torito cat path : /boot.catalog
El Torito images   :   N  Pltf  B   Emul  Ld_seg  Hdpt  Ldsiz         LBA
El Torito boot img :   1  BIOS  y   none  0x0000  0x00      4     1062782
El Torito boot img :   2  UEFI  y   none  0x0000  0x00  18432          81
El Torito img path :   1  /endless/grub/i386-pc/iso/eltorito.img
El Torito img opts :   1  boot-info-table grub2-boot-info
El Torito img path :   2  /endless/efi.img
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off
ISO image size/512 : 4253628
Partition offset   : 0
MBR heads per cyl  : 0
MBR secs per head  : 0
MBR partition table:   N Status  Type        Start       Blocks
MBR partition      :   1   0x80  0x00            0      4253628
MBR partition      :   2   0x00  0xef      4253628        18432

Generated by:

xorriso -as mkisofs -o ${OUTPUT} -r -graft-points -no-pad
--sort-weight 0 / --sort-weight 1 /endless
-b endless/grub/i386-pc/iso/eltorito.img
-no-emul-boot -boot-load-size 4 -boot-info-table --grub2-boot-info \
--grub2-mbr .../boot_hybrid.img \
-eltorito-alt-boot \
--efi-boot /endless/efi.img -no-pad \
-append_partition 2 0xef ${DIR_IMAGES_ENDLESS}/efi.img \
-iso-level 3 ${DIR_IMAGES}

so basically an ISO generated by "mbr_only_copy" method BUT (and this
is the most important thing) to have the image recognized by the UEFI
we had to change the partition type of the main partition from 0x83 to
0x00 with something like:

printf "\x00" | dd of=${OUTPUT} bs=1 count=1 seek=450 conv=notrunc

Can we do that using xorriso or is it worth to add a new option for
this? It seems that this is important for some stupid EFI firmware.

-- 
Carlo Caione  |  +39.340.80.30.096  |  Endless