WP76xx Linux without Legato

Just wondering, is it possible / has anybody used the WP76 modules without the Legato layer? We don’t need it, so it would be simpler not to have that extra layer of complexity and not have our software team learn a new framework, and would free up a bit of storage.

We would need:

  1. QMI (or ppp)
  2. GPS
  3. GPIO
  4. SD storage
  5. USB
  6. GPIO
  7. Audio

Has anybody done this, or are the services too integral with Legato?

Hi @sciscitatio, you can use the WP76 modems with PPP/AT/QMI interface to a host. The modem in this case will be just a bit pipe. You can also use it in ‘hybrid’ mode, bit-pipe with a host along with app(s) running on the the application core.

Thanks, yes we already did that, but I was more interested in the idea of removing unnecessary (to me) components from the build. I’m intending to use these modules in a commercial product so wanted to use a stripped-down OS build if at all possible. Our software guy assigned to this project has managed to set up a dev environment and compiled a fresh build using the Yocto tools but from what I can gather most if not all the documentation assumes a Legato build, so it’s not clear where dependencies lie.

We’ve done similar exercises on ARM SoC before, but nothing like these WP modules which seems to be a mix of open-source and proprietary.

Same here. Want to do a proper cross-compilation without using the developer studio/legato bollocks. Any ideas?

I wouldn’t hold your breath, this forum is about as lively as a snail on Valium.:sleeping:

Hi @stefandxm
You can use leaf to setup the toolchain etc for a release and compile Legato and Legato applications. Leaf instructions are here WP7601 update fails - no redSensorToCloud

You can also get the complete Linux source from the modem’s firmware components page and recompile it.

Hello, did you ever get this working? We are interested in the same thing.

Not really. We’ve just hired a developer to start work on building our system, but right now he’s tasked with getting some drivers built as I don’t want to use the hardware on the Mangoh dev boards; like the software ecosystem it’s pointlessly over-complicated and expensive for real world commercial applications.

TBH it’s probably going to be quicker, easier and cheaper for us just to get the bits we need working e.g. setting up the QMI interface, /dev/nmea to get GPS info and let the rest just sit there redundant.

After trying to port one of our apps over to the Legato system, I am beginning to realize the same thing. If you aren’t using Legato and the sandbox, what solution are you implementing to update the OS/RootFS? Updating the applications seems straight forward with a package manager. But I’m wondering about security and maintenance updates for the kernel, root fs, ect… Also, are you building your own OS distro using the WP bsp and yocto? I am also worried about LTS of the legato system and sandbox since it doesn’t seem to be taking hold in the community.

Hi @jimmy
Just commenting on the security aspect, the WP modem’s kernels are regularly updated with security fixes. As a reference, you can check section 5.3 in the WP77 R12 Customer Release Notes from https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-latest-release/