#1036619 grub2-686 does not see partitions with big offset

Package:
grub2
Source:
grub2
Description:
GRand Unified Bootloader, version 2 (dummy package)
Submitter:
root
Date:
2023-05-23 10:15:04 UTC
Severity:
normal
#1036619#5
Date:
2023-05-23 10:10:28 UTC
From:
To:
Dear Maintainer,

grub2 686 machines do not see partitioins with big offset from start of the disk. It has no issues see
partitions at the begining of the disk.

/dev/sda1          34       2047       2014 1007K BIOS boot
/dev/sda2        2048 3369748479 3369746432  1.6T Linux filesystem
/dev/sda3  3503966208 3638183935  134217728   64G Linux filesystem
/dev/sda4  3638183936 3772401663  134217728   64G Microsoft basic data
/dev/sda5  3772401664 3906619391  134217728   64G Linux filesystem
/dev/sda6  3906619392 3907028991     409600  200M EFI System
/dev/sda7  3369748480 3503966207  134217728   64G Linux filesystem

I tried sda7 as my debian partition and start from following:

* luks1/2+btrfs
* btrfs
* ext4

grub ls showing correct (hd0,gpt1-7). At least part_gpt works. Also grub does
see by sda2 btrfs parittion and it's content. But sda7 partition does not work!

1) 'cryptomount -a' report no erros and exit for booth luks1 and luks2
2) saying unknown partition about btrfs formatted drive
3) syaing unknown partition about ext4 formatted drive

It looks like grub simply does not recognize big offset partitions. I tried
boot using livecd debian 686 and have no issue mounting sda7 partition.

Full logs including dmesg and cpuinfo (livecd; chroot /dev/sda7).

https://linux-hardware.org/?probe=266235dc3b