[U-Boot] [PATCH 3/3] tests: py: dfu: Provide functionality to set test and dummy files alt settings

[Lukasz Majewski <l.majewski@samsung.com>]

Hi Stephen,

> On 04/08/2016 09:44 AM, Lukasz Majewski wrote:
> > After concatenation of "dfu_alt_info" variable from "dfu_alt_boot"
> > and "dfu_alt_system" it may happen that test and dummy files alt
> > settings are different than default 0 and 1.
> >
> > This patch provides ability to set different values for them.
> > It was the simplest possible solution - akin to the one from
> > original bash dfu tests.
> 
> > diff --git a/test/py/tests/test_dfu.py b/test/py/tests/test_dfu.py
> 
> > +        # - after concatenation dfu alt settings for test and
> > dummy files are
> > +        #   moved from 0 and 1 to other values
> 
> Similar formatting comments to the previous patch. I'd also re-word
> this to be much more generic, and simply state the it allows
> different alt settings to be used, rather than tieing the description
> to one possible reason why you might want to do that.

Ok, I will rewrite the description.

> 
> > +        "alt_num_test_file": "5",
> > +        "alt_num_dummy_file": "6",
> 
> This feels fragile. What if $dfu_alt_boot changes length? Does it
> make more sense to:
> 
> (a) Set alt_info_env_name to dfu_alt_boot instead, so that the
> settings specified by the test are always at a known position in the
> list, so we can always use alt setting 0 and 1.

Unfortunately, dfu_alt_boot (which depends on boot medium) is
immutable and set during boot time from CONFIG_DFU_ALT_BOOT_SD and
CONFIG_DFU_ALT_BOOT_EMMC

Only "dfu_alt_system" can be set by user.

> 
> or:
> 
> (b) Use names rather than numbers for the alt setting? 

I thought about this option. 

1. One possible solution would be to define:

"test_file_name": "file.bin"
"dummy_file_name": "dummy.bin"

at env__dfu_configs.

Afterwards, I could automatically set the "alt_info" property int the
same map:

"alt_info" : "%s ext4 0 2; %s ext4 0 2" % (test_file_name,
dummy_file_name)

As a result, I could use -a {test_file_name|dummy_file_name} to access
proper alt setting.



2. Another option would be to set the "dfu_alt_system" env variable and
then run "dfu-util -l" on host (or 'dfu 0 mmc 0 list') on target and
grep output for test_file_name and dummy_file_name and extract alt
setting numbers. 
This would require modification in the framework core code and hence I
decided to manually specify the alt settings number (as I did in the
bash version of those scripts).

However, as I look now for it, I think that option from point 1) seems
flexible enough. Stephen what do you think about it?

> Those should
> be position-independent. Presumably this would require a slightly
> large code change, since we'd need to move from %d to %s conversions
> when constructing the dfu command string, but that should be very
> easy.
> 
> If you take this approach, I'd suggest making the configuration file 
> name (alt_num_*_file above) match the Python variable name 
> (alt_setting_*_file) for consistency.
> 
> (c) Provide a way for the user to turn off the auto-concatenation
> feature.

This feature is already deployed and I would like to avoid changing it.

> 

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group