I always having the issues during updating bios under linux/ubuntu.
All bios updaters developed by vendors for processing under DOS/Windows, but very small amount of them have thoughts about linux users.
I have written article about using flashrom application for updating bios in ubuntu/linux(in ukrainian), but it is not universal and has limited support of devices.
Here I want to share ability to have boot image item in grub with freedos installed for making possible boot into and update bios for Your mobo.