I want to share some measurements that we did in the office for the initial boot steps, from POR until user code is executed from DDR. Measurements were made with no HAB and don't include Power time, which is device dependent. They cover the following two steps:
- boot decision
- fetching of image into DDR.
Platform used: i.MX6Q / Sabre AI
|Image Size||SD Class 4 on CPU CARD||NAND** on CPU CARD||Parallel NOR on CPU CARD|
|2KB||32 ms + 79* ms||25 ms||23 ms|
|166KB||40 ms + 79* ms||61 ms||56 ms|
|1MB||77 ms + 79* ms||247 ms||213 ms|
* Constant value, measured only once (after SD card insert/platform power up), does not appear for subsequent s/w resets.
** Samsung K9G4G08U0M
Thanks to Andreas S. for help.