Re: Grub Bios Boot filesystem description

[Raghav Gururajan]

> should I describe my Bios Grub filesystem in '(operating-system (file-systems 
> (list ...)))' or just
> only in '(operating-system (bootloader ...))' section?

You do not need to mention grub in "file-system" section of config. You have to 
mention just the device "sdX" NOT with the partition "sdXY", in the 
"boot-loader" section of the config. Assuming the device is formatted as GPT, 
you should have either "BIOS Boot Partition" (for BIOS systems) or "EFI Boot 
Partition" (for UEFI systems) on the device. In the "boot-loader" section of 
config; if you use "grub-bootloader", it will detect the BIOS Boot Partition 
and install grub on it (or) if you use "grub-efi-bootloader", it will detect 
the EFI Boot Partition and install grub on it.

> If I need to describe grub file system, so which type should I specify?

No need. See the above.

> If I do not need, how grub will know to boot from my root partition Linux 
> filesystem on /dev/sdb2 ?

The grub uses file-system drivers to detect file-systems and look for grub.cfg. 
As the grub.cfg (in /boot/grub of /dev/sdX2) was generated by guix based on the 
config file, it has information where to look for kernel.

Regards,
RG.