RTEMS mkimage.py for U-Boot scripts

[Andre.Nahrwold at dlr.de]

Hello,

in our laboratory setup we use different U-Boot scripts to control the boot behavior of our development board (Trenz TE0715 [1] on top of Trenz TE0706 [2]).

These simple scripts need to be converted into a script image using the mkimage command for U-Boot. [3]
We use the following command which works fine:

./mkimage -A arm -T script -C none -n "fancy name" -d bootscripts/rtems rtems.img
Image Name:   fancy name
Created:      Tue Jan 26 06:57:50 2021
Image Type:   ARM Linux Script (uncompressed)
Data Size:    324 Bytes = 0.32 KiB = 0.00 MiB
Load Address: 00000000
Entry Point:  00000000
Contents:
   Image 0: 316 Bytes = 0.31 KiB = 0.00 MiB

Because our setup also depends on the rtems-zynq-mkimg command and the rtems environment to be available we wanted to switch to the usage of the mkimage.py command which comes via RTEMS.
BUT every script image we generate with this tool behaves different than the one we generated with mkimage.
First of all is the output different, including a different resulting file size and a missing contents section.

mkimage.py -A arm -T script -C none -n "fancy name" -d bootscripts/rtems rtems.img
Image Name:    fancy name
Created:       Tue Jan 26 08:00:06 2021
Image Type:    none
Data Size:     316
Load Address:  0
Entry Point:   0

Adding the OS option with linux or u-boot does seem to change something, but the resulting script image is again not usable.

I became aware of this because when a script image like this is uploaded to U-Boot and sourced, no error occurs but also nothing else happens.
Usually it should print some information on what the script is doing and then well do its intended operations like it does when it is converted via the mkimage script.

Has somebody else had the same issue and maybe even overcome it?
Or does anybody have a clue where the problem may originate from?

Thanks in advance for the answer and help.

[1] https://wiki.trenz-electronic.de/display/PD/TE0715+TRM#TE0715TRM-KeyFeatures 
[2] https://wiki.trenz-electronic.de/display/PD/TE0706+TRM#TE0706TRM-KeyFeatures 
[3] https://www.denx.de/wiki/DULG/UBootScripts 

Best regards
Andre Nahrwold
--------------------------
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
German Aerospace Center
Institute for Software Technolog | SRV-OSS BS | Lilienthalpl. 7 | 38108 Braunschweig | Geb. 112C Raum 001
M.Sc. Andre Nahrwold | Telephone +49 531 295-3834 | andre.nahrwold at dlr.de
DLR.de