Platform ALT3800 as good target?

historical

Hi Elias,

thanks for reaching out.

On Wed, Jan 29, 2020 at 12:28:37AM +0100, Elias Devoldere wrote:

> I was playing with LTE modem R11e-4G based on ALT3800-B0 chipset.

I've read about Altair (now part of sony) based modems, but never had any actual contact with them.

It seems that one HL78 NB-IoT modem from Sierra Wireless as well as the L866
from Telit seems to be based on Altair, but I wasn't aware that Mikrotik is
also using Altair.

> I was amazed when I got a U-Boot console after command at+cfun=1,1 and
> sending several random characters. I assume it's not news for seasoned
> wolves who hunt here.

This is highly unexpected, of course.

> Is this behavior generally known?

I've never heard of it, certainly it was not a topic in Osmocom so far.

> Can this be a one-piece property (I have only one piece)?

possibly, but more likely it relates to the specific firmware build.

> Could it be useful for interesting research?

of course.

> Is there anyone who cares about it?

I do.

> I will try to extract parts of the memory using U-boot.

good luck!

> U-Boot 2012.10 (Aug 09 2018 - 10:17:38)
> mips-fourgee3100-linux-uclibc-gcc (0.1) 4.5.3

ok, so we know it's a MIPS architecture, and we know it's the fourgee3100
(Altair 3100) for whihc it was originally written.  The 3800 is likely
bcakwards compatible then.

> 'GUESS MODE - NO BOOT ALLOWED !!!'; fi

whatever a GUESS MODE is

> dtb_file=alt3802.dtb

3802 is even a more specific part number

> lte_fw=PS100_RealPHY.elf

also interesting that the PHY firmware comes as ELF file, would be interesting
to see what ELF architecture it is for.

> ver=U-Boot 2012.10 (Aug 09 2018 - 10:17:38)

always surprising what kind of stone age versions are in use :)

Please do keep us posed.  I odered one of those modems myself, too.

-- 
- Harald Welte <laforge at osmocom.org>            http://laforge.gnumonks.org/
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