Custom Linux Software + UBoot


#1

Hello,

We are evaluating using some devices of the WPxxx family on a custom board .

We already have our own Yocto based Linux distro for different machines. Some features require the Uboot bootloader.

By doing a brief/shallow documentation search I couldn’t find anything about custom device memory partitioning or how to flash UBoot for an initial custom Linux bring-up.

On the link below it seems to be implied that the unbrick tools (swicwe, swiflash) are tightly coupled to the partitioning scheme depicted there (Fixed system “ro” partitions plus “rw” overlays).

https://source.sierrawireless.com/resources/airprime/software/wpx5xx/wpx5xx-firmware-latest-release-components/

I guess that the Linux BSP is on the “meta-swi” layer so using our own distro shouldn’t be extremely problematic.

Is it possible to use Uboot instead of “lk” with low/medium efforts?

Can the device memory be repartitioned (avoiding Legato, changing the rootfs to don’t be overlayed, adding partitions for the UBoot environment, etc.)?

Thanks.


#2

Hi, have you tried posting this question or searching for resources on the Legato/mangOH forums https://forum.legato.io/ or https://forum.mangoh.io/? There could be information realted to what you need there.


#3

Hello.

Aren’t those forums for an IoT software layer and an Open Source board using the WP family?

I’m just asking here because I think that Sierra is the chip vendor, so I was expecting them to provide the flashing/unbricking bootloader bringup tools.

By looking at the processor diagrams on the website it looks like Legato is tightly coupled to the WP familiy but not to the HL series. I’ll keep reading.


#4

Legato is not tightly coupled with WP even though the platform adaptation layer that is currently provided with Legato is for the WP modems. Legato has been ported to RPi, http://legato.io/legato-docs/latest/buildPlatformMain.html

Changing the LInux software may not be as simple as Tocto distribution for the WP has been customized for the WP modems by Sierra. There is an initiative to separate the layers more explicitly, but it’s not there yet.

The HL modems do not use Legato as they are not smart modems as they do not have the ability to run customer’s embedded applications and are bit-pipe modems.


#5

So it seems that making a WP device to use UBoot + our distro would require more effort than usual then.

Thank you!