Boot Guix from Grub on Coreboot laptop

[znavko]

Hello! I have a laptop Lenovo Thinkpad burned with Coreboot and working on 
Trisquel. But some network bugs appeared after update (updates break almost 
every system I used except Guix) and I want to install Guix OS.
I burned an usb-stick that is booting perfectly on my PC, but it does not boot 
on the coreboot laptop. When I choose from the menu "Search ISO linux menu 
(USB)" it does not start booting from usb. And I enter grub command line and 
type:
> ls
... (usb1) (usb1,msdos2)
> set root=(usb1,msdos2)
> chainloader /efi/boot/bootx64.efi
error: unrecognized payload type.

I do not know what to do here.
I also tried to find 'vmlinuz' and 'initrd' on '(usb1)' but it's hard to find 
them there.
Can you help? Could Guix OS boot under Coreboot?