We are looking for application notes to assist with custom board bring-up efforts. Specifically, for IMX6ULL with configuration to support SPI NOR ('Serial ROM') boot on a ECSPIx port.
The problem we are attempting to diagnose... We are not seeing a successful 1st stage program loading outcome.
We are seeing signs-of-life (good things) from observing 1st stage program loading efforts:
- After reset, we see the expected ECSPI SCLK activity during 'Serial ROM' boot up (15MHz / correct for 3-byte SPI addressing Modes).
- About 8 milliseconds after reset recover, we observe the 1st ECSPI SCLK pulses begin to be visible.
- ECSPI clock activity indicates data is being streamed from SPI NOR for 3.4 milliseconds (at the 15MHz clock rate)
We know the DDR RAM connection to the IMX6ULL is good, and we can use Segger JLink JTAG adapters to pre-initialize DDR with uBoot, and run uBoot without the IMX6ULL's 1st stage program loader (without 'Serial ROM' boot)... so, we know need to diagnose reasons 'why?' the 1st stage program loader may not be successful.
We also know the data image within the ECSPIx connected SPI NOR flash is per our intended memory image, We are able to use uBoot 'sf probe', 'sf erase', 'sf write', 'sf read' commands to erase, burn and read back the SPI NOR targeted image.
Does NXP offer any App Notes which can help customers diagnose 1st Stage Program Loading Efforts, and... specifically for folks leveraging an ECSPIx port with a SPI NOR memory interface?
Thanks much in advance,