our stm32mp157F based custom board will not boot up, we see the panic error message on the uart interface.

[vbuon.1]

hi,

we are trying to flash our yocto build on our custom board using the stm32cubeprogrammer via usb in dfu mode. the flashing fails w/ the following message:

19:33:39 : Opening and parsing file: tf-a-stm32mp157f-nff-mx-usb.stm32

19:33:39 :  File         : tf-a-stm32mp157f-nff-mx-usb.stm32

19:33:39 :  Size         : 225596 Bytes

19:33:39 :  Partition ID : 0x01

19:33:39 : Download in Progress:

19:33:39 : File download complete

19:33:39 : Time elapsed during download operation: 00:00:00.550

19:33:39 : RUNNING Program ...

19:33:39 :  PartID:     :0x01

19:35:29 : Error: an error occured while uploading data from the virtual partition 0xF1

on the console we see the following message:

on the console we see the following log:

PANIC at PC : 0x2ffea97f

Exception mode=0x00000016 at: 0x2ffea97f

we've looked at the following troubleshooting guide:

https://community.st.com/s/article/FAQ-STM32MP1-bring-up-troubleshooting-guide

we have tried all three of the configurations for the HSE clock but nothing has worked.

we looked at the i2c4 lines connected to the pmic and see that the bootrom does try to communicate w/ the pmic. it configures register 0x10 by writing a 4 into it. and then it reads register 0x20. it seems that several microseconds after reading the pmic's register 0x20 the bootrom sends a panic error the console.

any suggestion on how to debug the problem would be appreciated.

cheers,

vince

[vbuon.1]

after debugging it appears that the problem is w/ our configuration of the device tree for the pmic. it seems that buck1 MUST be configured to have a maximum voltage of 1.35 otherwise the boot rom errors out. we are still trying to understand the relationship btwn the pmic device tree and the boot rom. there are other issues w/ our configuration of the device tree node for the pmic which are causing the bootup to fail.

we have not been able to find any documentation that tells us how to configure the device tree node for the pmic so that the bootup does not fail.we took some things out that we don't use in the pmic from the device tree which may not have the right to do. can you point us to a document that will tell us how to configure the pmic so that the bootup is successful.

thank you,

vince

[vbuon.1]

our device is not a usb host. therefore, we did not provide the usb otg feature in our device. bc of this we did not configure the boost regulator and the power switch 2 (pwr_sw2). however, it seems that the boot rom code is failing around this area. is it required that the boost regulator be configured, i.e., pins 33 (vlx_bst) and 32 (pgnd5) be supplied w/ power and ground and that pin 37 (sw_in) be connected to pin 34 (bst_out)?

thanks,

vince