certutil -d /etc/pki/pesign -N

efikeygen -C -S -k -n grub -c "CN=grub"

pesign -C grub.cer -c grub

rpmbuild -ba grub2.spec --define "_sourcedir $PWD" --define "_topdir $PWD/rpmbuild" --define "efi_vendor grub" --define "pe_signing_cert grub"

unpack everything

grub2-mkimage -v -C auto -O i386-pc --prefix '(,msdos1)/efi/grub' -o EFI/grub/i386-pc/core.img 'iso9660' 'fat' 'part_msdos' 'part_gpt' 'part_apple' 'biosdisk' 'xzio' 'gcry_crc'

fallocate -l 501M uefi-insecureboot-minimal.img

fdisk uefi-insecureboot-minimal.img

n

p

1

2048

enter

t

C

w

sudo losetup -Pf uefi-insecureboot-minimal.img

sudo mkfs.vfat -F 32 /dev/loop0p1

sudo mount /dev/loop0p1 mp

cd mp

cp -r ../../filesystem/EFI .

sudo grub2-bios-setup /dev/loop0 -d EFI/grub/i386-pc/ -v