Update fedora_chroot.md

fedora_chroot.md

@@ -20,6 +20,39 @@ sudo mount --bind /etc/resolv.conf /mnt/etc/resolv.conf
 sudo chroot /mnt
 ```
 
+### Info
+
+#### efi vars
+
+In order to successfully use efibootmgr the EFI variables filesystem must be accessible.
+
+```
+mount | grep efivars                                                          # check rw EFI vars
+mount -o remount,rw -t efivarfs efivarfs /sys/firmware/efi/efivars            # make rw if ro
+```
+
+#### Boot entries
+
+The path of the EFI image to boot must use \ (backslash) instead of / (forward slash)
+
+```
+# List
+efibootmgr
+
+# Add
+efibootmgr --create --disk /dev/nvme0n1 --part 1 -L Fedora -l \EFI\fedora\grubx64.efi  
+
+# Order
+efibootmgr -o 0000,0001,001C,001D,001E,001F,0020,0021,0022,0023,0024,0025
+
+# Show
+efibootmgr | grep Fedora
+# Boot0002* Fedora	HD(1,GPT,a90b01c2-def6-3d28,0x800,0x82000)/\EFI\fedora\grubx64.efi
+
+# Delete
+efibootmgr -b -0 -B
+```
+
 
 ### Grub