--- /dev/null
+From c9395ad54e2cabb87d408becc37566f3d8248933 Mon Sep 17 00:00:00 2001
+From: Christian Lamparter <chunkeey@gmail.com>
+Date: Sun, 1 Dec 2019 02:08:23 +0100
+Subject: [PATCH] powerpc: bootwrapper: force gzip as mkimage's compression
+ method
+
+Due to CONFIG_KERNEL_XZ symbol, the bootwrapper code tries to
+instruct the mkimage to use the xz compression, which isn't
+supported. This patch forces the gzip compression, which is
+supported and doesn't matter because the generated uImage for
+the apm821xx target gets ignored as the OpenWrt toolchain will
+do separate U-Boot kernel images for each device individually.
+
+Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
+---
+ arch/powerpc/boot/Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/powerpc/boot/Makefile
++++ b/arch/powerpc/boot/Makefile
+@@ -272,7 +272,7 @@ compressor-$(CONFIG_KERNEL_LZO) := lzo
+
+ # args (to if_changed): 1 = (this rule), 2 = platform, 3 = dts 4=dtb 5=initrd
+ quiet_cmd_wrap = WRAP $@
+- cmd_wrap =$(CONFIG_SHELL) $(wrapper) -Z $(compressor-y) -c -o $@ -p $2 \
++ cmd_wrap =$(CONFIG_SHELL) $(wrapper) -Z gzip -c -o $@ -p $2 \
+ $(CROSSWRAP) $(if $3, -s $3)$(if $4, -d $4)$(if $5, -i $5) \
+ vmlinux
+