Straight forward ManjaroGnome 20.1.1 hack to make both grub options "Advanced" and "Fallback initramfs" bootable

UPDATE 10/16/2020

Same issue seems to be affecting grub.cfg of ManjaroKDE 20.1.1 when setting flag "boot" to both partitions /boot/efi and /boot during run Manajaro's version of Calamaris Installer on bare metal . Bug doesn't show up in virtual environment .

Another issue to fix on both Manjaro's flavors is to run `sudo pacman -S edk2-ovmf` to enable KVM Guests UEFI support .

END UPDATE

Check  content  /boot folder 

Then manually change grub.cfg file 

[boris-ms7c85 boot]# ls -l
total 63872
-rw-r--r-- 1 root root    40960 сен 23 23:26 amd-ucode.img
drwx------ 3 root root     4096 янв  1  1970 efi
drwxr-xr-x 5 root root     4096 окт  8 10:19 grub
-rw------- 1 root root 40344731 окт  8 10:17 initramfs-5.8-x86_64-fallback.img
-rw------- 1 root root 18170430 окт  8 10:17 initramfs-5.8-x86_64.img
-rw-r--r-- 1 root root       21 сен 23 17:34 linux58-x86_64.kver
drwx------ 2 root root    16384 окт  8 10:11 lost+found
drwxr-xr-x 2 root root     4096 окт  1 15:57 memtest86+
-rw-r--r-- 1 root root  6808256 окт  1 15:57 vmlinuz-5.8-x86_64

 

Update grub.cfg

 

 menuentry 'Manjaro Linux (Kernel 5.8.11-1-MANJARO x64) (on /dev/sdb3)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/vmlinuz-5.8-x86_64--2cef925b-03a8-4231-97e7-6369703103f8' {
                insmod part_gpt
                insmod ext2
                set root='hd1,gpt2'
                if [ x$feature_platform_search_hint = xy ]; then
                  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  01f39e34-9af8-4138-acd2-bd17528fd114
                else
                  search --no-floppy --fs-uuid --set=root 01f39e34-9af8-4138-acd2-bd17528fd114
                fi
                linux /vmlinuz-5.8-x86_64 root=UUID=2cef925b-03a8-4231-97e7-6369703103f8 rw apparmor=1 security=apparmor resume=UUID=a6c70eb8-512e-4dd5-a5dc-0fa0c9300f96 udev.log_priority=3
                # initrd /amd-ucode.img <= commented out
                initrd /initramfs-5.8-x86_64.img
        }
        menuentry 'Manjaro Linux (Kernel 5.8.11-1-MANJARO x64 - fallback initramfs) (on /dev/sdb3)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/vmlinuz-5.8-x86_64--2cef925b-03a8-4231-97e7-6369703103f8' {
                insmod part_gpt

Same hack works on Manjaro KDE 20.1.1

Manually updated grub.cfg