PC BIOS & EDD problem

[Alexey Orishko]

Hi all,

Some time ago BIOS Enhanced Disk Drive specification got a new
revision where device path was changed from 8 to 16 bytes.

I see that the latest grub code in git has support for the latest specification:
include/grub/i386/pc/biosdisk.h:
...
grub_uint8_t device_path[16];

Are old BIOS versions supported somehow or simply abandoned?
Do I need to revert commit b828fb5d9c7575700a64751efbddd738e2b7c239 of
Vladimir Serbinenko to get old BIOS working?
Is there any difference between 32 and 64 bit version of grub in handling BIOS?

Regards,
Alexey