diff --git a/UPDATING b/UPDATING
--- a/UPDATING
+++ b/UPDATING
@@ -2485,16 +2485,48 @@
 	1.) recompile and reinstall the ZFS boot loader and boot block
 	(this is part of "make buildworld" and "make installworld")
 
-	2.) update the ZFS boot block on your boot drive
+	2.) update the ZFS boot block on your boot drive (only required when
+	doing a zpool upgrade):
 
-	The following example updates the ZFS boot block on the
-	freebsd-boot partition of a GPT partitioned drive ada0:
-	"gpart bootcode -p /boot/gptzfsboot -i $N ada0"
-	The value $N will typically be 1 (if booting from BIOS) or 2 (if
-	booting from EFI).
+	When booting on x86 via BIOS, use the following to update the ZFS boot
+	block on the freebsd-boot partition of a GPT partitioned drive ada0:
+		gpart bootcode -p /boot/gptzfsboot -i $N ada0
+	The value $N will typically be 1.
+
+	For EFI, there are many choices. The default installation places
+	loader.efi into the ESP in EFI\FREEBSD\LOADER.EFI. The following
+	updates it (assuming the ESP is on p1, and isn't already mounted):
+		mount -t msdos /dev/ada0p1 /boot/efi
+		cp /boot/efi/loader.efi /boot/efi/efi/freebsd
+	If you have a non-standard setup, please see the EFI notes section.
 
 	Non-boot pools do not need these updates.
 
+	EFI notes
+	---------
+	There are three configurations for FreeBSD EFI bootstraps.  The default
+	way is to use efibootmgr(8) to select the ESP to boot from. This
+	installs loader.efi into \EFI\FREEBSD\LOADER.EFI.  To update this
+	system, copy /boot/loader to \EFI\FREEBSD\LOADER.EFI on the ESP.
+
+	Some systems do not work with efibootmgr(8) due to bugs or limitations,
+	and instead use the fallback location of \EFI\BOOT\BOOTxxx.EFI.  For
+	newer installations, loader.efi, but for some older setups boot1.efi
+	will need to be used (both will work, but some older systems have an ESP
+	that is too small for a newer loader.efi).
+
+	Recent systems will have the ESP mounted on /boot/efi, but older ones
+	may not have it mounted at all, or mounted in a different
+	location. Older arm SD images with MBR used /boot/msdos as the
+	mountpoint. The ESP is a MSDOS filesystem.
+
+	The EFI boot loader rarely needs to be updated. The big exception is
+	when you do 'zfs upgrade' a root zpool. In that case, you must update
+	the ESP boot loader before the next reboot (otherwise the boot loader
+	may reject the zpool since it does not understand the new features).
+
+	See loader.efi(8) and uefi(8) for more details.
+
 	To build a kernel
 	-----------------
 	If you are updating from a prior version of FreeBSD (even one just