Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable

[Thomas Schmitt]

Hi,

Andrei Borzenkov wrote:
> MBR is created with 512B sector size but when GRUB is booted
> from CD-ROM sector size is 2KiB.

Ain't that a bug ?

GPT is recognized with 512. El Torito is recognized with its
weird mix of 512 for size and 2048 for block addresses.
The reason why APM is recorded with size 2048 is originally
not CD compatibility but the wish to combine APM and GPT.
(Else, the first APM entry and the GPT header would collide.)

Would it be possible that GRUB2 applies the feature of
self-identifying block size, in order to get MBR partitions
to the same level of support as GPT ?
(I never found traces of MBR block size other than 512. So one
 could set 512 as soon as partition type "msdos" is detected.
 I assume that "msdos" is recognized by the MBR magic number
 at bytes 510, 511 anyway.)


Have a nice day :)

Thomas