diff --git a/docs/extra-build-config.md b/docs/extra-build-config.md
index 150d23643..9c206ca0d 100644
--- a/docs/extra-build-config.md
+++ b/docs/extra-build-config.md
@@ -82,7 +82,7 @@ By default SD card media is used as boot media.
 To switch the boot media from SD card to USB memory, the following variables are supported
 in local.conf: `CMDLINE_ROOT_PARTITION` and `BOOT_MEDIA`.
 The default value of `CMDLINE_ROOT_PARTITION` is "/dev/mmcblk0p2" to mount SD card. If you want to mount USB memory partition, set CMDLINE_ROOT_PARTITION to "/dev/sda2".
-`BOOT_MEDIA` allows  `mmc` and `usb`. The "mmc" is required to load an image from the SD card, following the u-boot specification. Similarly, if you want to load a boot image file from USB memory, set BOOT_MEDIA to "usb".
+`BOOT_MEDIA` allows  `mmc` and `usb`. When U-Boot bootflow runs the boot script, the kernel is loaded from the device and partition holding the script. `BOOT_MEDIA` (device 0, partition 1) is only used when `devtype`, `devnum` and `distro_bootpart` are not set, for example when sourcing the script manually.
 
 For example, if you want to use USB boot, please define
 the following parameters in your local.conf file.
diff --git a/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in b/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in
index 58fd86a76..8b157ab05 100644
--- a/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in
+++ b/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in
@@ -1,4 +1,17 @@
 fdt addr ${fdt_addr} && fdt get value bootargs /chosen bootargs
-fatload @@BOOT_MEDIA@@ 0:1 ${kernel_addr_r} @@KERNEL_IMAGETYPE@@
-if test ! -e @@BOOT_MEDIA@@ 0:1 uboot.env; then saveenv; fi;
+
+# Load the kernel from the bootflow device; fall back to BOOT_MEDIA 0:1.
+if test -n "${devtype}" -a -n "${devnum}" -a -n "${distro_bootpart}"; then
+    fatload ${devtype} ${devnum}:${distro_bootpart} ${kernel_addr_r} @@KERNEL_IMAGETYPE@@
+else
+    fatload @@BOOT_MEDIA@@ 0:1 ${kernel_addr_r} @@KERNEL_IMAGETYPE@@
+fi
+
+# uboot.env lives on mmc 0:1. Only create it when booted from there (not
+# on another image's SD card) and without the per-boot bootflow variables.
+if test "${devtype}" = mmc -a "${devnum}" = 0 -a "${distro_bootpart}" = 1 -a ! -e mmc 0:1 uboot.env; then
+    env delete devtype devnum distro_bootpart prefix
+    saveenv
+fi
+
 @@KERNEL_BOOTCMD@@ ${kernel_addr_r} - ${fdt_addr}