Re: Is it possible to dual-boot both MBR & GPT without changing BIOS settings on laptop

On 2025-11-11 13:19, Java Jive wrote:
> On 2025-11-11 03:45, Paul wrote:
>>
>> On Mon, 11/10/2025 7:27 PM, Java Jive wrote:
>>>
>>> Then reboot, and it all works.
> 
> Except, I've discovered, OSs won't hibernate, all that happens is that 
> the screen locks, the PC doesn't even sleep, let alone hibernate.

I wrote this some time ago, so can not be sure now what was going on 
then, but my suspicion is that it was the same as I recently discovered 
on one particular PC ...

The PC has a single GPT disk dual-booting between Windows 11 & Ubuntu 
24.  I have two GRUB entries to boot Windows 11.  The first is a 
conventional Windows Boot Manager entry in the EFI partition, the second 
is similar but installed in the Windows 11 partition \EFI folder.  If 
Windows 11 is booted via the first option, it hibernates, but if it 
booted via the second option, it won't hibernate as originally I 
described above.  I think it's something to do with Ubuntu/GRUB not 
being able to access some needed data on the ntfs partition when booting.

The relevant entries in /boot/grub/grub.cfg are as follows:

# Boots and hibernates
menuentry 'Windows Boot Manager (on /dev/sda1)' --class windows --class 
os $menuentry_id_option 'osprober-efi-E00A-0248' {
         savedefault
         insmod part_gpt
         insmod fat
         set root='hd0,gpt1'
         if [ x$feature_platform_search_hint = xy ]; then
             search --no-floppy --fs-uuid --set=root 
--hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1
E00A-0248
         else
           search --no-floppy --fs-uuid --set=root E00A-0248
         fi
         chainloader /efi/Microsoft/Boot/bootmgfw.efi
}
# Boots but does not hibernate
menuentry 'Windows 11 Professional (on /dev/sda2)' --class windows 
--class os $menuentry_id_option 'osprober-efi-53C598050A7F9BDA' {
         savedefault
         insmod part_gpt
         insmod ntfs
         set root='hd0,gpt2'
         if [ x$feature_platform_search_hint = xy ]; then
           search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 
--hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 53C598050A7F9BDA
         else
           search --no-floppy --fs-uuid --set=root 53C598050A7F9BDA
         fi
         chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

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