[openwrt/openwrt] ath79: expand factory.bin support for some Senao Engenius boards

[LEDE Commits]

ynezz pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/4d0c442a0a2fdc84ff0dc2c7106455d15c03defe

commit 4d0c442a0a2fdc84ff0dc2c7106455d15c03defe
Author: Michael Pratt <mcpratt at pm.me>
AuthorDate: Sun Oct 4 22:54:36 2020 -0400

    ath79: expand factory.bin support for some Senao Engenius boards
    
      Newer EnGenius software that still uses the tar.gz platform
      instead of the custom header requires more checks for upgrading,
      but their script includes a way to skip them...
      the existence of a file in the tar.gz called failsafe.bin
    
      Their upgrade script has these lines:
    
      \#pass check when upload with full image file
      [ "${errcode}" -eq "1" ] && [ -f failsafe.bin ] && errcode="0"
    
      This overrides the script's "errcode" variable
      which can be set if any of the following actions/checks fail:
    
      - untarring of the upload
    
      - magic number for kernel: "2705"
    
      - magic num for rootfs: "7371" or "6873"
    
      - md5sums for each file in the format
            filename:md5
    
      - existence of a file matching FWINFO*
            that it has boardname in the name somewhere (grep)
            that the 4th field of separator "-" is at least 3 (version)
    
      Otherwise we would need to generate md5sums in this strange format
      and touch a file with specific requirements in the name.
    
      This does not effect boards where the advanced checks do not apply.
    
    Signed-off-by: Michael Pratt <mcpratt at pm.me>
    [fixed SoB to match From:]
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 target/linux/ath79/image/generic.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/ath79/image/generic.mk b/target/linux/ath79/image/generic.mk
index 5bb247c58e..101c7597b8 100644
--- a/target/linux/ath79/image/generic.mk
+++ b/target/linux/ath79/image/generic.mk
@@ -75,6 +75,7 @@ endef
 define Build/engenius-tar-gz
 	-[ -f "$@" ] && \
 	mkdir -p $@.tmp && \
+	touch $@.tmp/failsafe.bin && \
 	echo '#!/bin/sh' > $@.tmp/before-upgrade.sh && \
 	echo ': > /tmp/_sys/sysupgrade.tgz' >> $@.tmp/before-upgrade.sh && \
 	$(CP) $(KDIR)/loader-$(DEVICE_NAME).uImage \