Re: Does grub-mkrescue support UEFI hybrid USB/DVD images?

[Thomas Schmitt]

Hi,

Andrei Borzenkov wrote:
> Not eltorito, but normal ESP.

That's somewhat appeasing.


> returning (hd0,gpt2) would also be wrong here - ESP on CD image is
> empty, we need to somehow jump from ESP to full ISO image.

One could allow nested partitions and put whole-ISO partitions
into the various tables. Debian "amd64" ISOs do it that way.
They boot on BIOS via ISOLINUX and on EFI via GRUB2.

  MBR partition table:   N Status  Type        Start       Blocks
  MBR partition      :   1   0x80  0x00            0       454656
  MBR partition      :   2   0x00  0xef         3440          896
  MBR partition path :   2  /boot/grub/efi.img
  ...
  GPT partname local :   1  ISOHybrid
  ...
  GPT start and size :   1  0  454600
  ...
  GPT partname local :   2  ISOHybrid1
  ...
  GPT start and size :   2  3440  896
  GPT partition path :   2  /boot/grub/efi.img

MBR partition 1 and GPT partition 1 cover the whole ISO.
Partitions 2 mark the ESP.

But Vladimir is clearly opposed to nested or overlapping
partitions. And all partition editors seem to join his opinion.


Have a nice day :)

Thomas