We bought a Compex WPJ 428 board + a SIMCom 8202G LTE/5GNR modem and we try to make it work on OpenWRT

Find a file

Quentin Dufour 3385c48101 Add some doc		2021-03-22 10:32:50 +01:00
img	Add a README	2021-03-22 09:25:31 +01:00
config	Track diffconfig	2021-03-22 09:11:13 +00:00
README.md	Add some doc	2021-03-22 10:32:50 +01:00

README.md

WPJ428 + SIMCOM 8202G

We try to build a FOSS 5GNR Router with OpenWRT. Some challenges we have encountered so far:

OpenWRT stable misses a patch to enable our board ethernet port -> we compile from source
The Modem Manager simtech plugin does not declare 5GNR

Flash OpenWRT from uboot

(Configure your computer with a static IP address 192.168.1.2/24 and make sure you have a running tftp server containing your image)

First connect your UART cable on the router:

Launch minicom

sudo minicom -D /dev/ttyUSB0

Then boot the router. Press repeatidly [ENTER] to get the following prompt:

(IPQ40xx) #

Then enter the following commands:

set ipaddr 192.168.1.1
set serverip 192.168.1.2
ping ${serverip}
sf probe
tftpboot 0x84000000 openwrt-ipq40xx-generic-compex_wpj428-squashfs-sysupgrade.bin
sf erase 0x00180000 +$filesize
sf write 0x84000000 0x00180000 $filesize
bootipq

Compile

make menuconfig
scripts/diffconfig.sh > ../wpj428/config
make download
make -j $(nproc)

To inject a config file:

# Append changes to bottom of .config
cat config >> .config
# Apply changes
make defconfig
make download
make -j $(nproc)

Flash OpenWRT from OpenWRT (!)

Copy the firmware in router's /tmp. Why /tmp? Your router has more volatile storage than persistent one, moreover you will overwrite the persistent storage. So, copy the firmware in /tmp! Next, we will use the sysupgrade command. -v is verbose, -n ask openwrt to erase configuration files (ie. ask for a factory reset).

sysupgrade -v -n /tmp/openwrt-ipq40xx-generic-compex_wpj428-squashfs-sysupgrade.bin

Get root on MimoAP

Download a backup from your router firmware
Extract it, edit /etc/shadow, replace the hash of the root user with the one from the admin user
Recompress the folder hierarchy
Import this new archive as backup in MimoAP
Run ssh root@192.168.1.1 (replace with the IP address of your router) and use your admin password
Enjoy! (But you should really install a vanilla OpenWRT instead)

Flash OpenWRT from Compex ROM (MimoAP)

Not written

Flash MimoAP/OpenWRT with Compex tools on Uboot