[openwrt/openwrt] ar71xx: Ubiquiti Airmax M: add relocate-kernel to invalidate cache

[LEDE Commits]

neoraider pushed a commit to openwrt/openwrt.git, branch lede-17.01:
https://git.lede-project.org/eed9d40133fe6468cc253d0345c7d7332d2aaa7c

commit eed9d40133fe6468cc253d0345c7d7332d2aaa7c
Author: Matthias Schiffer <mschiffer at universe-factory.net>
AuthorDate: Thu Apr 26 20:04:48 2018 +0200

    ar71xx: Ubiquiti Airmax M: add relocate-kernel to invalidate cache
    
    Some Ubiquiti U-boot versions, in particular the "U-Boot 1.1.4.2-s956
    (Jun 10 2015 - 10:54:50)" found with AirOS 5.6, do not correctly flush the
    caches for the whole kernel address range after decompressing the kernel
    image, leading to hard to debug boot failures, depending on kernel version
    and configuration.
    
    As a workaround, prepend the relocate-kernels loader, which will invalidate
    the caches after moving the kernel to the correct load address.
    
    Reported-by: Andreas Ziegler <dev at andreas-ziegler.de>
    Signed-off-by: Matthias Schiffer <mschiffer at universe-factory.net>
---
 target/linux/ar71xx/image/ubnt.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/ar71xx/image/ubnt.mk b/target/linux/ar71xx/image/ubnt.mk
index 65ed708..899d5d0 100644
--- a/target/linux/ar71xx/image/ubnt.mk
+++ b/target/linux/ar71xx/image/ubnt.mk
@@ -47,6 +47,7 @@ define Device/ubnt-xm
   UBNT_TYPE := XM
   UBNT_BOARD := XM
   UBNT_CHIP := ar7240
+  KERNEL := kernel-bin | patch-cmdline | relocate-kernel | lzma | uImage lzma
   IMAGES := sysupgrade.bin factory.bin
   IMAGE/factory.bin = $$(IMAGE/sysupgrade.bin) | mkubntimage-split
   IMAGE/sysupgrade.bin = append-kernel | pad-to $$$$(BLOCKSIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)