[coreboot] How to give control to bootable USB

[Taiidan at gmx.com]

On 06/13/2017 10:22 AM, Dhanasekar Jaganathan wrote:

> Hi All,
>
> I am trying to install ONIE from USB which has ONIE installer. Actually, I
> am using GRUB2 as a payload.  If Coreboot display list of bootable device,I
> can select USB which will install a OS in the hard disk.  As I understood
> that Coreboot won't display list of available bootable device (not like
> vendor bios).I don't know how to give control to bootable USB or boot a
> bootable USB by coreboot. Can you please help me on this?.
>
>
> Thanks,
> Dhanasekar
Assuming you are booting a standard linux distro iso:
syslinux_configfile (*TAB* to see what is available

then simply for instance syslinux_configfile 
(usb0,msdos1)/isolinux/syslinux.cfg (or w/e)

also configfile (ahci0,msdos1)/grub2/grub.cfg to load a grub cfg

Ideally you would add a grub cfg to the coreboot image that does 
something like load a config file from a specified local disk so that it 
is easy to update (ie: no re-flashing) instructions for that are on the 
wiki.

SeaBIOS would provide the classic AMI style F12 selection menu, but I 
don't like it due to how many times I have accidentally enabled option 
rom execution by forgetting to include the configuration file.