[SOLVED] Dual boot Windows 10

[Chrisdb]

why do I need a BIOS partition when I should run in UEFI mode?

You don't.

A BIOS boot partition is needed by GRUB to start a non-UEFI system on a GPT disk:

https://en.wikipedia.org/wiki/BIOS_boot ... onents.svg

As you do not have such a partition then you cannot be booting in non-UEFI mode with GRUB.

So what is the best approach to do this?

You said Debian starts but goes to a blank screen. Maybe you have a graphics problem rather than a grub problem. Once you manage to get back to having Debian boot with grub-efi, try adding "nomodeset" to the grub kernel line. You may get a basic graphical interface from where you can set up your graphics properly.

But it works in legacy mode without problems

[Head_on_a_Stick]

Does the `efibootmgr` command work after you have booted in "Legacy" mode?

^ Please answer this question.

I think that perhaps you are in fact booted in UEFI mode even though you have selected "Legacy" mode — UEFI firmware is absolute rubbish in my experience so perhaps that knob is broken on your machine.

Otherwise you must be booting by some other method (which seems highly unlikely) but I have no idea why the boot would succeed with "Legacy" mode enabled but not otherwise

The only thing I can suggest is to attempt to re-install the bootloader:

https://wiki.debian.org/GrubEFIReinstall

@p.H, any ideas?

[Chrisdb]

Does the `efibootmgr` command work after you have booted in "Legacy" mode?

^ Please answer this question.

I think that perhaps you are in fact booted in UEFI mode even though you have selected "Legacy" mode — UEFI firmware is absolute rubbish in my experience so perhaps that knob is broken on your machine.

Otherwise you must be booting by some other method (which seems highly unlikely) but I have no idea why the boot would succeed with "Legacy" mode enabled but not otherwise

The only thing I can suggest is to attempt to re-install the bootloader:

https://wiki.debian.org/GrubEFIReinstall

@p.H, any ideas?

Yep efibootmgr works

[Head_on_a_Stick]

^ In which case you are booted in UEFI mode and your firmware is a POS

Leave "Legacy" mode enabled and forget about it.

[Chrisdb]

I was thinking the same thing

Just one last question, when I try to power off or reboot, I get a black screen and it takes a while before
the shutdown actually happens.

Could this be related to the efi mode?

[Wheelerof4te]

Install inxi and post the terminal output of:

Code: Select all

inxi -G

As sunrat mentioned, your problem might be graphics. Have you noticed any other slowdows? Like programs take too long to open, Youtube plays flaky etc.

[Chrisdb]

Install inxi and post the terminal output of:

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inxi -G

output:

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Graphics:  Card: Advanced Micro Devices [AMD/ATI] Carrizo
           Display Server: X.org 1.19.2 drivers: ati,vesa (unloaded: modesetting,fbdev,radeon)
           tty size: 80x24 Advanced Data: N/A for root



As sunrat mentioned, your problem might be graphics. Have you noticed any other slowdows? Like programs take too long to open, Youtube plays flaky etc.[/quote]

You said Debian starts but goes to a blank screen. Maybe you have a graphics problem rather than a grub problem. Once you manage to get back to having Debian boot with grub-efi, try adding "nomodeset" to the grub kernel line. You may get a basic graphical interface from where you can set up your graphics properly.

My apologies sunrat, it was indeed a problem with the graphics driver -> AMD/ATI
I installed 'firmware-amd-graphics' and now it works!! Thx!!

I still find it strange that I could start the system if Legacy was enabled though.....

So now I'm wondering how I can install the firmware package during netinstall?

[Head_on_a_Stick]

I still find it strange that I could start the system if Legacy was enabled though.....

Me too.

Was nomodeset enabled for the so-called "Legacy" boot?

Check with

Code: Select all

cat /proc/cmdline

Perhaps "Legacy" mode disables your graphics card, check the output of `lspci` and see if it's listed.

[Chrisdb]

I don't think 'nomodeset' was set, but I can't check it now as I need to reinstall my system.

Anyway thx everyone for your help.