If anybody is following this thread awaiting a solution for booting a eMMC board; I'm still empty handed.
Truth is since this isn't my daytime job I have very limited time to try things out, even less these past few weeks.
I did get last night off and tried some stuff but regardless my attempts I was empty handed.
I'm now trying to compile the u-boot image myself rather than patching existing ones, but the u-boot fork
doesn't seem to have support for booting over UART.
I did find something slightly amusing though, there seems to be two u-boot forks implementing the a38x support.
There's the MarvellEmbeddedProcessors which SolidRun has forked of, then there's the mainline support now based
on code from Stefan Roese (https://email@example.com/msg189083.html).
The Turris Omnia project has a u-boot fork of the mainline version, which also has fixes for the UART kwb image generation.
Since the Turris Omnia will be shipping in just a month I assume their fork is somewhat stable so I will harvest whatever
of the UART patches I can and see if any of it fixes my problems.
Funny thing is though that SolidRun tech. support guys boot through UART, but they never replied on my last email so
I'm clueless on how they do it.
Edit: Finally got the damn thing booting from UART, it all boiled down to the timing of the first xmodem package basically.
What I did was I put the kwboot command line in a while loop and reset the device every time I got the "Bad message".
After about ten attempts it finally booted!
Terrific! I got a reply from SolidRun on an inquire about the optional eMMC. It is possible to order through their support, it's an additional $7 which means a total of $177 for the board with eMMC and the uSOM module.
The uSOM module delivered with the ClearFog Pro is indeed the A388.