From 42a4f1c69dab20e93f48fa4f3db1810af00f684e Mon Sep 17 00:00:00 2001
From: kszaq <kszaquitto@gmail.com>
Date: Thu, 2 May 2019 10:44:57 +0200
Subject: [PATCH] linux: amend uimage load address for proper decompression

When kernel image is compressed, it is first loaded
to RAM at load address specified in command line,
then unpacks to loadaddr provided by uImage.

For decompressed image not to overwrite compressed
data, uncompressed image load address needs to be
shifted by compressed image size + 1 MiB alignment.
---
 packages/linux/package.mk | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packages/linux/package.mk b/packages/linux/package.mk
index bfabdce7d5..81c286c9d7 100644
--- a/packages/linux/package.mk
+++ b/packages/linux/package.mk
@@ -243,8 +243,19 @@ make_target() {
   fi
 
   if [ -n "$KERNEL_UIMAGE_TARGET" ] ; then
+    # determine compression used for kernel image
     KERNEL_UIMAGE_COMP=${KERNEL_UIMAGE_TARGET:7}
     KERNEL_UIMAGE_COMP=${KERNEL_UIMAGE_COMP:-none}
+
+    # calculate new load address to make kernel Image unpack to memory area after compressed image
+    if [ "$KERNEL_UIMAGE_COMP" != "none" ] ; then
+      COMPRESSED_SIZE=$(stat -t "arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_TARGET" | awk '{print $2}')
+      # align to 1 MiB
+      COMPRESSED_SIZE=$(( (($COMPRESSED_SIZE - 1 >> 20) + 1) << 20 ))
+      KERNEL_UIMAGE_LOADADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_LOADADDR + $COMPRESSED_SIZE ))")
+      KERNEL_UIMAGE_ENTRYADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_ENTRYADDR + $COMPRESSED_SIZE ))")
+    fi
+
     mkimage -A $TARGET_KERNEL_ARCH \
             -O linux \
             -T kernel \