What does the SPI NOR bootloader expect to see and where is the right documentation ?

JSchn.5 · ‎2022-04-08

When booting off SPI NOR I would expect the device (an ST32MP151D) to possibly check the device ID then read a block starting from 0. Where is this fully documented ?

What I actually see is two pairs of negative pulses on nCS then it floats open circuit. It's all within some tens of microseconds. The device is loaded with two copies of my TF-A and one U-Boot at the addresses in the TSV which are 0, 256k and 512k.

Where is the documentation or application note on what exactly it does ?

There is nothing in UART4 (PC10 and PC11).

PatrickF · ‎2022-04-08

Hi @JSchn.5 ,

did you already check information in wiki ?

especially https://wiki.st.com/stm32mpu/wiki/STM32MP15_ROM_code_overview

https://wiki.st.com/stm32mpu/wiki/STM32MP15_ROM_trace_analyzer

Did you build your binaries (including header) and flashed Serial-NOR using ST tools ?

If you are trying to program Flash by yourself, maybe look at this old post which show an example of Serial-NOR boot debug.

https://community.st.com/s/question/0D50X0000BiDo0fSQC/stm32mp157aab-failed-to-boot-from-nor-qspi-baremetal

Regards

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JSchn.5 · ‎2022-04-08

Thank you for that. In the meantime we have seen that three byte addresses are expected and no prizes for guessing something about the device we chose.