From 4ced62d585f83206ea81a2355072bdc248651988 Mon Sep 17 00:00:00 2001
From: Ian Leonard <antonlacon@gmail.com>
Date: Mon, 20 Jun 2022 19:32:40 +0000
Subject: [PATCH] linux: gzip 64bit kernels on RPi

RPi firmware since around September 2020 is able to decompress
gzipped kernels prior to handing over control. Arm64 kernels do not
do self-decompression, so use the firmware's capability.

Signed-off-by: Ian Leonard <antonlacon@gmail.com>
---
 packages/linux/package.mk | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/linux/package.mk b/packages/linux/package.mk
index baa7d36bb1..3d2ebef66a 100644
--- a/packages/linux/package.mk
+++ b/packages/linux/package.mk
@@ -282,6 +282,12 @@ makeinstall_target() {
       fi
     done
   elif [ "${BOOTLOADER}" = "bcm2835-bootloader" ]; then
+    # RPi firmware will decompress gzipped kernels prior to booting
+    if [ "${TARGET_KERNEL_ARCH}" = "arm64" ]; then
+      pigz --best --force ${INSTALL}/.image/${KERNEL_TARGET}
+      mv ${INSTALL}/.image/${KERNEL_TARGET}.gz ${INSTALL}/.image/${KERNEL_TARGET}
+    fi
+
     mkdir -p ${INSTALL}/usr/share/bootloader/overlays
 
     # install platform dtbs, but remove upstream kernel dtbs (i.e. without downstream