2020-06-15 07:18 PM
Hi All.
I want to use the battery to power the RETRAM so that the contents of the RETRAM can be preserved even if the board is not powered.
To do this, I connected the battery to the VBAT pin and set the "PWR_CR2_RREN" value to the "PWR_CR2" register of the M4 core firmware.
However, when booting from Linux, the value set in the "PWR_CR2" register disappears.
When booting in "Engineering Mode" and running only with the firmware of the M4 core, the setting value of the "PWR_CR2" register does not disappear even when the main power is turned off.
Is there anything I need to add when I create the "dts" file to enable that feature?
Please give me a lot of advice.
Thanks
Regards
Machilus
Solved! Go to Solution.
2020-06-16 06:06 AM
Hi @Machilus ,
You are right - the value of "PWR_CR2_RREN" should preserve the reset.
But in this case it's not device tree responsible. You need to modify the appropriate section of TF-A.
Best regards,
Milan
2020-06-16 06:06 AM
Hi @Machilus ,
You are right - the value of "PWR_CR2_RREN" should preserve the reset.
But in this case it's not device tree responsible. You need to modify the appropriate section of TF-A.
Best regards,
Milan
2020-06-16 05:44 PM
0
2020-06-16 05:45 PM
Hi @mleo (ST Employee)
Thank you for your advice.
Can you give me detailed advice on which part of TF-A should be modified?
Or please send me a link to ST or wiki site that can be referred to for modification of TF-A.
I'll be waiting for your reply.
Thanks
Regards
Machilus
2020-06-23 10:24 PM
This problem is solved. Thank you for your help in solving the problem.
Regards
Machilus
2022-01-13 01:24 PM
Was there a link sent? I'm interested in this information as well.
Thanks,
Ben