ramips: mt7620: add kernel size for Jboot devices

Since few months multiple users reported problems with various JBoot
devices. [0][1][2][3] All of them was bricked.

On my Lava LR-25G001 it freezes with current snapshot:

CDW57CAM_003 Jboot B695
Giga Switch AR8327 init
AR8327/AR8337 id   ==> 0x1302
JRecovery Version R1.2 2014/04/01 18:25
SPI FLASH: MX25l12805d 16M
.
.
(freeze)

The kernel size is >2048k.

I built current master with minimal config and it boots well:

CDW57CAM_003 Jboot B695
Giga Switch AR8327 init
AR8327/AR8337 id   ==> 0x1302
JRecovery Version R1.2 2014/04/01 18:25
SPI FLASH: MX25l12805d 16M
.
...........................
Starting kernel @80000000...
[    0.000000] Linux version 5.4.124

Kernel size is <2048k.

Jboot bootloader isn't open source, so it's impossible to find
solution in code. It looks, that some buffer for kernel have 2MB size.

To avoid bricked devices, this commit introduces 2048k limit kernel
size for all jboot routers.

[0] https://bugs.openwrt.org/index.php?do=details&task_id=3539
[1] https://eko.one.pl/forum/viewtopic.php?pid=254344
[2] https://eko.one.pl/forum/viewtopic.php?id=20930
[3] https://eko.one.pl/forum/viewtopic.php?pid=241376#p241376

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
[remove Fixes:]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit e1d8a14cd0a9f8844f9ebb8ca220780b0ce5d6db)

diff --git a/target/linux/ramips/image/mt7620.mk b/target/linux/ramips/image/mt7620.mk
index fd7e42bf228186bac84481ae225f794b810a31ac..56941f2b9c73601555cbb90a06bb7e6897bd2dcb 100644 (file)
--- a/target/linux/ramips/image/mt7620.mk
+++ b/target/linux/ramips/image/mt7620.mk
@@ -62,6 +62,7 @@ TARGET_DEVICES += alfa-network_tube-e4g
 define Device/amit_jboot
   DLINK_IMAGE_OFFSET := 0x10000
   KERNEL := $(KERNEL_DTB)
+  KERNEL_SIZE := 2048k
   IMAGES += factory.bin
   IMAGE/sysupgrade.bin := mkdlinkfw | pad-rootfs | append-metadata
   IMAGE/factory.bin := mkdlinkfw | pad-rootfs | mkdlinkfw-factory