LS1043 soft reset persistent register

[sebastianpancea]

Hi,

I'm running Linux(LSDK19.06 based) on the LS1043 SoC and I need to pass the reboot reason to ATF/u-boot.

I searched the reference manual for a register that has its value persisted over soft resets but I couldn't find such a register.

Could you please advise on how to pass some information at Linux reboot to the bootloader stages?

Thank you!

[yipingwang]

You could execute "fw_printenv" and "fw_setenv" to read and write u-boot environment in Linux before invoke soft reset. About how to create the configuration file, please refer to the last post in https://community.nxp.com/t5/Layerscape/How-to-build-fw-printenv-and-fw-setenv-for-LS1012AFRWY-OpenW...

[sebastianpancea]

Hi @yipingwang ,

Thank you for your reply!

Using "fw_setenv" tool, means storing the variable into non-volatile memory.

What I was asking for, is a CPU register or RAM zone that is persistent between reboots, and is cleared only when the SoC is powered down.

Other SoCs have such registers, for example IMX6: https://community.nxp.com/t5/i-MX-Processors/iMX6-persistent-data-storage/m-p/648339#M99095

Any idea of a similar feature on LS1043?

[yipingwang]

Please refer to "DCFG_CCSR_RSTRQSR1" in LS1043 Reference Manual.

[sebastianpancea]

Hi @yipingwang ,

I see that this register has multiple read only bitfields.

It also has "Reserved" zones that are marked as writable.

So if I write to these "Reserved" zones(for example bits 24-31) should I expect the values to be persistent between resets?

[sebastianpancea]

I tried to write to this register in the "Reserved" zones but it doesn't work