Re: [meta-ti] meta-ti setup suggestions for beaglebone (SoC AM335x)

["Denys Dmytriyenko" <denys@ti.com>]

Hi, Luca,

To answer your questions:

* It is always recommended to use so-called stable branches, that correspond 
to Yocto release names - dunfell, zeus, etc. It is expected that master can 
be broken at times due to active development. Also, we do extensive internal 
testing on those stable branches and apply tags when such testing completes 
successfully - i.e. internal releases. You can see those tags in the repo - 
ti2020.01.00, ti2020.00.04, etc. Between those tags it is unlikely, but still 
possible something may get inadvertently broken. Which is what happened for 
you here, unfortunately - we were migrating from zeus to dunfell between 
ti2020.00.04 and ti2020.01.00. If you are new and don't know where to start, 
I'd recommend picking the latest release tag in the series - the highest third 
number or no number at all, like ti2020.00=ti2020.00.04. As you can see, we 
just started with ti2020.01.xx series with the first .00 tag in dunfell. Other 
than that, we follow the standard Yocto Project and Open Source practices.

* There is very little difference between am335x-evm and beaglebone machines 
in meta-ti. You can think of it as beaglebone being a leaner variant of 
am335x-evm. The actual differences can be seen in the config files:
http://arago-project.org/git/?p=meta-ti.git;a=blob;f=conf/machine/am335x-evm.conf;hb=HEAD
http://arago-project.org/git/?p=meta-ti.git;a=blob;f=conf/machine/beaglebone.conf;hb=HEAD
They both build on top of a common ti33x.inc file that specifies the entire 
SoC family. From there, beaglebone uses fewer DTBs, ttyS0 as console, no 
built-in LCD/touchscreen and no UBI configuration. At some point it used own 
U-boot defconfig, but that got deprecated. So, in other words, beaglebone is 
a subset of am335x-evm machine. It is exactly the same BSP (kernel, u-boot, 
FWs, etc.) for both of them, with just minor packaging differences.

-- 
Denys


On Thu, May 07, 2020 at 11:59:15AM -0700, Luca wrote:
> Thanks Charlie,
> 
> now it is booting fine and from your explanation I can also try to 
> understand the reason behind the error I was getting.
> 
> Actually both the commits you pointed out had already caught my attention 
> because I was trying to get a first bootable setup before using a custom a 
> .wic.in file.
> Considering that, I think my doubts about which branch or tag is stable are 
> somehow still valid.
> 
> May I ask you if you can at least partially solve the doubts that I 
> expressed?
> * suggested/tested branch, tag or commit for beaglebone and amx335 SOC? 
> Maybe it would be useful to know that for all the supported SOCs.
> * which are the differences between the machines am335-evm and beaglebone? 
> Since beaglebone uses am335 SOC there should be only a "reduced amount of 
> differences" right?
> Maybe I am wrong, but I think a short explanation in the main README, at 
> least for the first question, would save a few hours for newbies like me and 
> possibly a few minutes even to experienced users. Maybe the explanation is 
> already in the right place and I simply don't know where I have to look for 
> it.
> 
> Regards
> Luca