Hello @lloydc,
If you want to update the available packages list, you can type: opkg update
Next, if you want to upgrade the packages, you can type: opkg upgrade
But if you want the latest OpenWrt System, you can follow the wiki below to flash the latest image:
https://wiki.seeedstudio.com/OpenWrt-Getting-Started/#initial-set-up
Can I know which version of the Compute Module you have? eMMC or non-eMMC version?
Best Regards,
Lakshantha