use invd instead of wbinvd in real mode start code

Heiko Schocher hs at
Tue Feb 18 12:06:43 CET 2020

Hello Andy,

Am 18.02.2020 um 11:45 schrieb Andy Shevchenko:
> On Tue, Feb 18, 2020 at 7:48 AM Heiko Schocher <hs at> wrote:
>> Am 17.02.2020 um 17:04 schrieb Wolfgang Denk:
>>> In message <CAHp75VfuzMm=CPJ86GspRiiv+AAYbs+jFDKP2rfNmYhsmvOY+w at> you wrote:
>>>> On Mon, Feb 17, 2020 at 5:09 PM Wolfgang Denk <wd at> wrote:
>>>>> In message <CAHp75VdUY7zJfkc4YV-KTt1aEKg9Ggy6PsJAEOkgo9eCtQx9Kg at> you wrote:
>>>>>>>> git bisect is the usual way to figure out the culprit.
>>>>>>> Too much work to do this way.
>>>>> If you find bisecting is too much work you probably still do it
>>>>> manually. Why don't you use  tbot  to automize such boring and time
>>>>> consuming tasks?
>>>> Bisection time something about 10%, while 90% is flashing the board
>>>> and, given the result, triggering either bad or good next cycle.
>>> Yes, and this is exactly what tbot was made for - automating such
>>> repeating, boring activities.  It is wasted life time to do this
>>> manually.
>> Yes, that is one benefit if you use tbot, see git bisect help:
>> You only have to pass to the function the good commit as string and
>> a tbot python function which tests the current commit. This test
>> function now can call other functions like run a complete build of
>> current source, copy the resulting images let say to a tftp directory,
>> install the new images on the device, reboot it and run tests on the U-Boot
>> comamndline on the real board ...
>> So using tbot for the complete development process makes a lot of sense,
>> also as you have at the end a complete setup for testing your board (not
>> only U-Boot also linux or other commandline based machines are possible
>> to automate), it is easy to start a CI ... as tbot is a commandline tool
>> a simple cron job is enough .. or you can integrate it easily into jenkins,
>> buildbot, gitlab CI runner ... whatever CI you use...
>> If you want to get help setting up tbot, feel free to ask me or Harald
>> directly or on the tbot mailinglist:
> How the feed back line is organized? I mean how host system will know that
>   a) we done flash correctly?
>   b) the booted image is bad or good?

For both questions the answer is, that you need to write a testcase
which answer this question.

For a) you flash the image in some way through U-Boot commands. You
start this commands from a tbot testcase written in python and parse
the output and/or return code of the command and than decide ...

Same for b) reboot the board, check if new version is installed
by parsing the U-Boot bootlog, than start U-Boot commands to find
out, if current installed version is good or bad.

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at

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