AM5728: Data retention during software reboot

Colombo Carlo

Part Number: AM5728

HI everybody ,

please on a AM5728 running Linux , idea is to save some variables/status ( few bystes about 128Bytes in total ) and then force from the command line a reboot ( so SW reboot , no power off ) ( this is due to enter some special configurations/settings etc ) . AM5728 will reset and boot . Due to bug i862 and our workaround all SW resets go to PORZ : are DATA in internal RAM kept or internal RAM Is reinizialided ? any workaround to reboot keeping 1 KBof DATA ?

we can use internal RAM or DDR ( using self refresh for example ) , but what we need on system level is to be able when booting to "see" these variables .

any suggestion @ system level ?

thank you

bye

Carlo

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi Carlo,

Your best bet will be to store this data in external storage (EEPROM, eMMC, SD card, etc). Internal RAM is used by the SPL during the boot process, and as for DDR, the EMIF will be reinitialized at every reboot.

0 Biser Gatchev-XID over 8 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

I have notified the factory team about this too. They will post here.

0 Rogerio Almeida over 8 years ago in reply to Biser Gatchev-XID

TI__Mastermind 26195 points

Carlo, can we close this? is customer OK with this alternative?

0 Colombo Carlo over 8 years ago in reply to Rogerio Almeida

TI__Mastermind 23305 points

Hi Rogerio ,

please I would like final confirmation from fab ( as per Biser post ) if any area in the internal RAM could be used to store parameters for the rebooting.

it is clear and confirmed on external DDR, but on internal having a small area for parameters could be useful .

any input/suggestion on how to achieve my goal no external extra device is very welcome

thank you

bye

Carlo

0 Rogerio Almeida over 8 years ago in reply to Colombo Carlo

TI__Mastermind 26195 points

Carlo,
OK, I will double check with Biser who he is working with....

0 Mukul Bhatnagar over 8 years ago in reply to Rogerio Almeida

TI__Guru* 82575 points

Carlo
No way to retain internal RAM content post PORz. This use-case was not envisioned for this device and not supported in design.

regards
Mukul

0 Colombo Carlo over 8 years ago in reply to Mukul Bhatnagar

TI__Mastermind 23305 points

Hi Mukul ,

thank you , please what about using a - Reboot command in Linux Console ? do you have same issue ?

thank you

bye

Carlo

0 Steve Kipisz over 8 years ago in reply to Colombo Carlo

TI__Genius 15510 points

Even on a reboot, the internal RAM is used by the boot ROM and SPL. You really need some type of storage (SPI, NOR, NAND) for saving data.

Steve K.

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AM5728: Data retention during software reboot