[arm-allstar] UART4 and uEnv.txt file(s) location

[David McGough]

Hi Fredric,

The flash drive partition containing the uboot bootstrap isn't mounted by
default. Also, when compared to all the other "vanilla" BBB distros, there
is added complexity to the uboot code in the arm-allstar BBB release. This
complexity is due to the desirability of having only a single distributed
flash image that'll work on any of the current BBB hardware/firmware
releases available (rev B or rev C, in particular).

Anyhow, there are two (2) uEnv files which should be changed. The first is
uEnv.txt and the second is uEnv.tx2. You need to append
"capemgr.enable_partno=BB-UART4" to the end of the "options=" variable
already in the uEnv files, just like you suggest in your post.

...So, for a fresh v1.1 install, this line in uEnv.tx* would become:
optargs=coherent_pool=1M capemgr.enable_partno=BB-UART4

Here are the basic steps, using the "vi" editor--substitute another 
editor if preferred.

Login as root.

mount /dev/mmcblk0p1 /mnt
vi /mnt/uEnv.txt
vi /mnt/uEnv.tx2
umount /mnt
reboot

Note that I have confirmed that this does work as expected on a fresh v1.1 
installation. And, sorry for the verbosity--I'm trying to document this in 
a way where it can be found and followed by all interested arm-allstar 
users.


73, David KB4FXC



On Sun, 3 Aug 2014, Fredric Moses wrote:

> Hello, trying to activate other UART ports on the BBB.  On other distros I
> just add  capemgr.enable_partno=BB-UART4  to the uEnv.txt file and on boot
> it turns on the /dev/ttyO4 for use...  But not finding that file in this
> distro..
> 
> Thanks,
> --
> Fredric Moses - W8FSM - WQOG498
> fred at moses.bz
>