How did you verify you’ve BIOS and not UEFI?

Is this an error.?? Grub-installed worked fine. But while generating grub config these extra lines shows up

And when i reboot, instead of grub menu. Its display some error message. Something like no pxe rom found. And takes me to the boot devices menu

How did you verify you’ve BIOS and not UEFI?

My bios has no uefi support. And i installed arch previously with the same method. But with ext4 partiton format. Now trying with btreefs

How did you verify that?

I went to bios and there were no functionality that uefi has. And my hdd uses mbr partition style. I don’t know that much about bios tbh

If you saw no mention of EFI or secure boot in the firmware setup and the device is older than 11 years, you’ve BIOS.
Otherwise you’ve UEFI

Yeah i have bios then

Looks fine then, if it actually boots

I tried about 4-5 times from yesterday. Grub menu doesnt come.when i reboot. Let me reboot this time

Didn’t boot 🙁

Describe what happens more

After i reboot . a blank screen come up , wait some sec and then this comes on the screen. Maybe the other boot interface from boot order menu. Then my usb which has ventoy installed boots up..

What if you try to boot from the one time menu? Are you sure your drive is actually set to boot first?

Also do this again but show lsblk before rebooting

I am sure its has top priority. Also I manually select my hdd to boot from it. Nothing comes up

You mean generate the grub config again??

Reinstall it and generate config yes

On ext4 installation there was no issue. But with btrfs this happens. I really want to setup with btrfs. (. For snapping ). Guess i am doing something wrong .

I said already, i tried at least 4-5 times already with the same process. Should i tell you briefly about what i did from the begining??

does grub support /boot on btrfs in mbr?

It supports it. As i read it on the arch wiki

https://wiki.archlinux.org/title/btrfs#GRUB

it’s talking about partitionless disk. that means whole of /dev/sda, are you doing that or do you have any other partition that particular disk?

I have only one hdd. And its on /dev/sda. I installed grub on /dev/sda

I get that. hmm.
are you using swap or anything else?
can you post output of lsblk? as Martin said

Yes. Also should i share my fstab??

if you wish.

Ok

does the disk uses gpt or mbr?

Mbr

output of fdisk -l