Flashing your router is always risky procedure. You're doing it at your own risk, you take the full responsibility for any action you choose, we cannot be held liable for any damage you do to your device, other devices, any other person or animal.
Easier end-user flashing (no soldering needed) of OpenWrt firmware on UBNT M2HP (and maybe others?) devices running airOS v6.1.7.
mtd utility shipped in flash-sysupgrade.sh is licensed under GPLv2, everything else in this repository is free and unencumbered software released into the public domain.
| Device | Status | Factory | Sysupgrade |
|---|---|---|---|
| Bullet M2HP | Working |
Yes | Yes |
We currently have access to just one type of device so can't confirm if similar approach might work on other devices with same airOS version. Feel free to test it and let us know.
-
You need to flash your UBNT M2HP with airOS v6.1.7 firmware no other airOS version is currently supported
-
Download this toolkit sources
git clone https://github.com/true-systems/ubnt-bullet-m2hp-openwrt-flashing
cd ubnt-bullet-m2hp-openwrt-flashing
You can find more details about this method bellow.
make flash-sysupgrade FW_OWRT=/path/to/your/openwrt-ath79-generic-ubnt_bullet-m2hp-squashfs-sysupgrade.bin
You can find more details about this method bellow.
make flash-factory FW_OWRT=/path/to/your/openwrt-ath79-generic-ubnt_bullet-m2hp-squashfs-factory.bin
Example output from successful flashing sessions:
- Flashing factory image in flash-factory.log.
- Flashing sysupgrade image in flash-sysupgrade.log.
For legal reasons, we can't redistribute patched binaries. To get patched fwupdate.real command with removed RSA image signature checking directly from your router with default IP address 192.168.1.20 use following commands.
make ubntbox.patched REMOTE_UBNT=ubnt@192.168.1.20
mv ubntbox.patched fwupdate.real
Before running every flash command, we create backup of currently running factory firmware image in firmware-backup.bin. You can then restore your router running OpenWrt with 192.168.1.1 IP address back to this firmware by using this make target.
make restore REMOTE_OWRT=root@192.168.1.1
It's not possible to use fwupdate.real utility for flashing OpenWrt to UBNT devices anymore as it allows flashing of
signed firmware images only:
XW.v6.1.7# fwupdate.real -m /tmp/openwrt-ath79-generic-ubnt_bullet-m2hp-squashfs-factory.bin -d
...
Current: XW.ar934x.v6.1.7.32555.180523.1754
New ver: XW.ar934x.v6.0.4-OpenWrt-r8452+9-e95e9fc
Versions: New(393220) 6.0.4, Required(393220) 6.0.4
FW Part: "kernel"(1), MAGIC: 'PART', Base: 0x9F050000, DLen: 0x00100000, PLen: 0x00100000
FW Part: "rootfs"(2), MAGIC: 'PART', Base: 0x9F150000, DLen: 0x00280004, PLen: 0x00660000
Bad Image Structure
Signature check failed
So we were left with probably these remaining flashing methods:
- solder serial console and use TFTP for image flashing using
tftpbootwith initramfs image - try to flash sysupgrade image using
mtdover SSH in airOS - dissassemble and patch
fwupdate.realcommand so it would accept and flash unsigned OpenWrt factory firmware images
For end users, it's always more convenient to find some flashing method which
wouldn't involve any soldering, so we've first tried to find out if it would be
possible to flash OpenWrt with mtd over SSH in airOS. We've found out that
it's doable.
Then just out of the curiosity and for some fun, we've tried to patch out RSA
signature checking from fwupdate.real utility and check if it would allow us
flashing unsigned factory firmware image generated by OpenWrt. We've found out,
that it's doable also.
You can read more details about those two methods in more detail bellow.
This approach is using patched fwupdate.real command from ubntbox utility.
We've simply removed Bad Image Structure and Signature check failed checks,
so it's now possible to flash factory images built with OpenWrt.
radiff2 with JSON output shows what was patched out in ubntbox.patched:
r2@6608438f7a41:~$ radiff2 -j /data/ubntbox /data/ubntbox.patched
{"files":[{"filename":"/data/ubntbox", "size":715136, "sha256":"73460d7205549e1298fd0dad718edd61d06b8db07aecc637a41cbb547630e587"},
{"filename":"/data/ubntbox.patched", "size":715136, "sha256":"ca06d93741b30bdcb3a8b0577545aa0c32c4b5d9ac88f8580bae5a2774c890c3"}],
"changes":[{"offset":57104,"from":"16e0", "to":"0000"},
{"offset":57107,"from":"038f9982", "to":"00000000"},
{"offset":57112,"from":"10", "to":"00"},
{"offset":57115,"from":"772410ff2d92e4", "to":"00000000000000"},
{"offset":57123,"from":"1402e420212484", "to":"00000000000000"},
{"offset":57131,"from":"3803c028210320f809", "to":"000000000000000000"},
{"offset":57141,"from":"9e30231040", "to":"0000000000"},
{"offset":57147,"from":"0a8fbc", "to":"000000"},
{"offset":57151,"from":"288f8283f88f8480288f99814c8c45", "to":"000000000000000000000000000000"},
{"offset":57168,"from":"0320f80924846d148fbc", "to":"00000000000000000000"},
{"offset":57179,"from":"2810", "to":"0000"},
{"offset":57183,"from":"662410ff2c", "to":"0000000000"},
{"offset":60576,"from":"16f1fc878f848028", "to":"0000000000000000"}]
Unfortunately we can't redistribute patched ubntbox.patched binary, but you
can get patched ubntbox from your router by just running make ubntbox.patched command.
You can find output from flashing session of factory image with patched ubntbox.patched in flash-factory.log.
This approach is using mtd utility from Kamikaze 8.09.2
for flashing OpenWrt sysupgrade image. Unfortunately this is not so easy either, as there seems to be some flash write
lock protection in place, kernel is probably expecting some secret cookie, before it would allow writing to MTD flash:
XW.v6.1.7# dd if=/dev/zero of=/tmp/kernel bs=$((0x100000)) count=1
XW.v6.1.7# /tmp/mtd write /tmp/kernel kernel
Unlocking kernel ...
Writing from /tmp/kernel to kernel ...
XW.v6.1.7# md5sum /tmp/kernel
b6d81b360a5672d80c27430f39153e2c /tmp/kernel
XW.v6.1.7# md5sum /dev/mtd2
30c85e4d3c1a88c566d83678055025b9 /dev/mtd2
And it seems that fwupdate.real utility is able to unlock this flash
protection, so as a workaround (until proper fix) we can simply initiate
flashing of the factory v6.1.7 firmware image and interrupt it during the
flashing process:
XW.v6.1.7# fwupdate.real -m /tmp/XW.v6.1.7.32555.180523.1754.bin -d
Found mtd block: /dev/mtd0(u-boot)
...
Block on '/dev/mtd3' at 00060000(len: 00010000) has no changes.
[%7 ]
^C
Now the flash should be unlocked. Then we just need to solve missing firmware partition in the airOS firmware, but
this is doable as we can split the sysupgrade image to kernel and rootfs parts:
XW.v6.1.7# cat /proc/mtd
dev: size erasesize name
mtd0: 00040000 00010000 "u-boot"
mtd1: 00010000 00010000 "u-boot-env"
mtd2: 00100000 00010000 "kernel"
mtd3: 00660000 00010000 "rootfs"
mtd4: 00040000 00010000 "cfg"
mtd5: 00010000 00010000 "EEPROM"
Flashing part of the sysupgrade image to the kernel partition and the rest of the image to rootfs:
CI_BLKSZ=65536
fw="/tmp/openwrt-ath79-generic-ubnt_bullet-m2hp-squashfs-sysupgrade.bin"
rootfs_size=0x$(grep rootfs /proc/mtd | cut -d ' ' -f2)
kernel_size=0x$(grep kernel /proc/mtd | cut -d ' ' -f2)
kernel_blocks=$(($kernel_size / $CI_BLKSZ))
dd if="$fw" bs=$CI_BLKSZ count=$kernel_blocks 2>/dev/null | /tmp/mtd -e kernel write - kernel
dd if="$fw" bs=$CI_BLKSZ skip=$kernel_blocks 2>/dev/null | /tmp/mtd -r -e rootfs write - rootfs
You can do all this steps manually or just use content of this repository for more automated process.
You can find complete output from flashing session of sysupgrade image with make flash-sysupgrade command using above explained approach in flash-sysupgrade.log.