yields for the downloaded ISO, iso=groovy-desktop-amd64.iso :
Drive current: -indev 'groovy-desktop-amd64.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record : El Torito , MBR grub2-mbr cyl-align-off GPT
Media summary: 1 session, 1431622 data blocks, 2796m data, 350g free
Volume id : 'Ubuntu 20.10 amd64'
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off GPT
ISO image size/512 : 5726488
Partition offset : 16
MBR heads per cyl : 0
MBR secs per head : 0
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x80 0xcd 64 5715808
MBR partition : 2 0x00 0xef 5715872 9952
GPT : N Info
GPT disk GUID : 7631942462da4c4797ccfb75ca94a436
GPT entry array : 2 248 separated
GPT lba range : 64 5726424 5726487
GPT partition name : 1 490053004f004800790062007200690064003100
GPT partname local : 1 ISOHybrid1
GPT partition GUID : 1 7631942462da4c4797cdfb75ca94a436
GPT type GUID : 1 a2a0d0ebe5b9334487c068b6b72699c7
GPT partition flags: 1 0x1000000000000001
GPT start and size : 1 5715872 9952
El Torito catalog : 678 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 4 679
El Torito boot img : 2 UEFI y none 0x0000 0x00 9952 1428968
El Torito img path : 1 /boot/grub/i386-pc/eltorito.img
El Torito img opts : 1 boot-info-table grub2-boot-info
El Torito img blks : 2 2488
The new ISO yields:
Drive current: -indev 'test.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, 1431606 data blocks, 2796m data, 347g free
Volume id : 'ISOIMAGE'
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off
ISO image size/512 : 5726424
Partition offset : 16
MBR heads per cyl : 0
MBR secs per head : 0
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x80 0xcd 64 5715808
MBR partition : 2 0x00 0xef 5715872 9952
El Torito catalog : 678 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 4 679
El Torito boot img : 2 UEFI y none 0x0000 0x00 9952 1428968
El Torito img path : 1 /boot/grub/i386-pc/eltorito.img
El Torito img opts : 1 boot-info-table grub2-boot-info
El Torito img blks : 2 2488
which is what i proposed to debian-cd and debian-live a year ago.
The GPT of the original ISO is not valid because the MBR partition table
has two partitions. GPT would be valid only if there is a single MBR
partition of type 0xee, which covers the range from LBA 1 up to the ISO's
end.
Hi,
> https:/ /launchpad. net/ubuntu/ +source/ cd-boot- images- amd64/7
Oh. This explains why there is still an invalid GPT in cdimage. ubuntu. com/daily- live/current/ groovy- desktop- amd64.iso
http://
which i downloaded 2 days ago.
Above change has at its end:
+ echo 'xorriso -as mkisofs [...] boot/grub/ efi.img [...] appended_ partition_ 2:all:: [...] like_isohybrid -isohybrid- gpt-basdat [...]' > xorriso-cmd.txt
-append_partition 2 0xef images/
-e --interval:
-part_
To blame for the invalid GPT is "-part_ like_isohybrid -isohybrid- gpt-basdat" .
------- ------- ------- ------- ------- ------- ------- ------- ------- ------- --
I downloaded a new groovy- desktop- amd64.iso and repacked it without these
options:
dd if=groovy- desktop- amd64.iso bs=512 count=1 \ groovy- desktop- amd64.mbr. img
of=
dd if=groovy- desktop- amd64.iso bs=512 skip=5715872 count=9952 \ groovy- desktop- amd64.efi. img
of=
xorriso -as mkisofs \ i386-pc/ eltorito. img \
-no-emul- boot -boot-load-size 4 -boot-info-table --grub2-boot-info \ desktop- amd64.mbr. img \ partition 2 0xef groovy- desktop- amd64.efi. img \ alt-boot \ appended_ partition_ 2:all:: \
-no-emul- boot \ offset 16 -r \
-o test.iso \
-J -joliet-long -l \
-b boot/grub/
--grub2-mbr groovy-
-append_
-eltorito-
-e --interval:
-partition_
/mnt/iso
The numbers 5715872 and 9952 can be obtained by "/sbin/fdisk -l" or by
xorriso inspection.
This inspection
iso=groovy- desktop- amd64.iso
xorriso -indev "$iso" -report_system_area plain -report_el_torito plain
yields for the downloaded ISO, iso=groovy- desktop- amd64.iso :
Drive current: -indev 'groovy- desktop- amd64.iso' 797ccfb75ca94a4 36 079006200720069 0064003100 797cdfb75ca94a4 36 487c068b6b72699 c7 i386-pc/ eltorito. img
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record : El Torito , MBR grub2-mbr cyl-align-off GPT
Media summary: 1 session, 1431622 data blocks, 2796m data, 350g free
Volume id : 'Ubuntu 20.10 amd64'
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off GPT
ISO image size/512 : 5726488
Partition offset : 16
MBR heads per cyl : 0
MBR secs per head : 0
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x80 0xcd 64 5715808
MBR partition : 2 0x00 0xef 5715872 9952
GPT : N Info
GPT disk GUID : 7631942462da4c4
GPT entry array : 2 248 separated
GPT lba range : 64 5726424 5726487
GPT partition name : 1 490053004f00480
GPT partname local : 1 ISOHybrid1
GPT partition GUID : 1 7631942462da4c4
GPT type GUID : 1 a2a0d0ebe5b9334
GPT partition flags: 1 0x1000000000000001
GPT start and size : 1 5715872 9952
El Torito catalog : 678 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 4 679
El Torito boot img : 2 UEFI y none 0x0000 0x00 9952 1428968
El Torito img path : 1 /boot/grub/
El Torito img opts : 1 boot-info-table grub2-boot-info
El Torito img blks : 2 2488
The new ISO yields:
Drive current: -indev 'test.iso' i386-pc/ eltorito. img
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, 1431606 data blocks, 2796m data, 347g free
Volume id : 'ISOIMAGE'
System area options: 0x00004a00
System area summary: MBR grub2-mbr cyl-align-off
ISO image size/512 : 5726424
Partition offset : 16
MBR heads per cyl : 0
MBR secs per head : 0
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x80 0xcd 64 5715808
MBR partition : 2 0x00 0xef 5715872 9952
El Torito catalog : 678 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 4 679
El Torito boot img : 2 UEFI y none 0x0000 0x00 9952 1428968
El Torito img path : 1 /boot/grub/
El Torito img opts : 1 boot-info-table grub2-boot-info
El Torito img blks : 2 2488
which is what i proposed to debian-cd and debian-live a year ago.
The GPT of the original ISO is not valid because the MBR partition table
has two partitions. GPT would be valid only if there is a single MBR
partition of type 0xee, which covers the range from LBA 1 up to the ISO's
end.
Have a nice day :)
Thomas