diff -Nru u-boot-2021.01+dfsg/debian/changelog u-boot-2021.01+dfsg/debian/changelog
--- u-boot-2021.01+dfsg/debian/changelog	2021-04-21 12:05:00.000000000 -0500
+++ u-boot-2021.01+dfsg/debian/changelog	2021-08-17 20:45:55.000000000 -0500
@@ -1,3 +1,10 @@
+u-boot (2021.01+dfsg-3ubuntu10) hirsute; urgency=medium
+
+  * Implement u-boot-sifive.postinst to upgrade u-boot in loader1/loader2
+    partitions upon package upgrades. (LP: #1936370)
+
+ -- William 'jawn-smith' Wilson <william.wilson@canonical.com>  Tue, 17 Aug 2021 20:45:55 -0500
+
 u-boot (2021.01+dfsg-3ubuntu9) hirsute; urgency=medium
 
   * sifive-unleashed-default-fdt-files.patch: split into unleashed &
diff -Nru u-boot-2021.01+dfsg/debian/u-boot-sifive.postinst u-boot-2021.01+dfsg/debian/u-boot-sifive.postinst
--- u-boot-2021.01+dfsg/debian/u-boot-sifive.postinst	1969-12-31 18:00:00.000000000 -0600
+++ u-boot-2021.01+dfsg/debian/u-boot-sifive.postinst	2021-08-17 20:45:48.000000000 -0500
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+##DEBHELPER##
+
+set -e
+
+case "$1" in
+    configure)
+        target=""
+        if grep -q '^SiFive HiFive Unleashed A00$' /sys/firmware/devicetree/base/model; then
+            target="sifive_fu540"
+        fi
+        if grep -q '^SiFive HiFive Unmatched A00$' /sys/firmware/devicetree/base/model; then
+            target="sifive_hifive_unmatched_fu740"
+        fi
+        if [ -n "$target" ] && [ -e /dev/disk/by-partlabel/loader1 ] && [ -e /dev/disk/by-partlabel/loader2 ]; then
+            dd if=/usr/lib/u-boot/$target/u-boot-spl.bin of=/dev/disk/by-partlabel/loader1
+            dd if=/usr/lib/u-boot/$target/u-boot.itb of=/dev/disk/by-partlabel/loader2
+        fi
+        ;;
+esac
+
+exit 0