i.MX8QM rev B boot delay

[robsingle]

I'm seeing a three minute delay when booting the i.MX8QM rev B from SD card after a power-up. By "boot delay" I mean nothing is printed out to the serial port for three minutes, then U-Boot starts printing after the delay. The same SD card works in another i.MX8QM system of a slightly different design. After booting the system runs fine from the SD card. I don't see the delay if I do a reboot without a power-cycle. So far I haven't seen the delay with eMMC. Power looks OK. Any ideas what to look at?

[robsingle]

This didn't resolve my issue. We're using an SOM from TQ Group. We supply one voltage and their SOM creates the other sequenced voltages. They also did the DDR design. They say they don't see the problem on their EVB with the SOM. I was wondering if there is any way to figure out what the processor is doing during these three minutes before the first U-Boot message appears. Also, have there been any issues with the SD card interface, or specific SD cards?

[igorpadykov]

one can try to find source of delay debugging it, use AN12631

Normal and Secure Debug for i.MX8/8X Family of Applications Processors

Best regards
igor

[igorpadykov]

Hi Rob

one can check if power supplies and clocks come up in proper time and stable using

i.MX 8QuadMax/i.MX 8QuadXPlus Hardware Developer’s Guide

Also may be recommended to rebuild from scratch image specific for that board design:

use RPA tool and ddr test, follow documentation for build steps:

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-8-8X-Family-DDR-Tools-Release/ta-p/...

Best regards
igor