The actual configuration of GRUB is based on four files that are described below:
/boot/grub/menu.lst
This file contains all information about partitions or operating systems that can be booted with GRUB. Without this information, the GRUB command line prompts the user for how to proceed. For details, see Editing Menu Entries during the Boot Procedure.
/boot/grub/device.map
This file translates device names from the GRUB and BIOS notation to Linux device names.
/etc/grub.conf
This file contains the commands, parameters and options the GRUB shell needs for installing the boot loader correctly.
/etc/sysconfig/bootloader
This file is read by the perl-bootloader library which is used when configuring the bootloader with YaST and every time a new kernel is installed. It contains configuration options (such as kernel parameters) that will be added by default to the bootloader configuration file.
https://www.suse.com/documentation/opensuse121/book_opensuse_reference/data/sec_grub_basic.html