AM5728: Boot sequence issue

david kasper

Part Number: AM5728

SYSBOOT pins on my AM5728 Phytec EVM are configured as follows:

- Primary Boot Device = SD Card

- Secondary Boot Device = QSPI NOR FLASH

Per Section 33.3.3 of the AM572x Sitara TRM (SPRUHZ6L) the device list should contain the SD card and QSPI FLASH. If I insert an empty SD card then the processor appears to halt. I thought the booting loop of ROM startup code would proceed to the QSPI FLASH device and execute the MLO and app stored in QSPI FLASH (i.e. since no valid software image exists on the SD card).

FYI - QSPI boot works fine if the empty SD card is removed.

Please confirm if the ROM startup code is supposed to proceed to QSPI FLASH when no valid software image exists on the SD card.

Thanks,

Dave

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

What you describe is normal behavior. Once the ROM code queries the MMC interface, it will detect the SD card and try to boot from it. Since the card is empty the ROM code will hang in a deal loop until the AM572x internal watchdog timer expires, and the device is reset. Then the same sequence of events will follow, and so on.

0 david kasper over 6 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

Biser,

Thank you for clarifying the ROM bootloader behavior.

Regards,

Dave

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AM5728: Boot sequence issue