Add some doc

README.md

@@ -6,7 +6,7 @@ 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 the router
+## 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)
 
@@ -59,6 +59,34 @@ 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
+
+  1. Download a backup from your router firmware
+  2. Extract it, edit `/etc/shadow`, replace the hash of the `root` user with the one from the `admin` user
+  3. Recompress the folder hierarchy
+  4. Import this new archive as backup in MimoAP
+  5. Run `ssh root@192.168.1.1` (replace with the IP address of your router) and use your `admin` password
+  6. 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
+
+*Not written*
+
 ## Logs
 
 uboot logs: