Hardware related delays
The times listed in Boot time - Summary and Summary of reduced boot time are all relative to the time when the processor starts executing code. There are delays related to the hardware, such as PMIC power rail sequencing, that occur before the processor starts executing code. The table below lists delays for cold and warm reset for respective board. Note that the delays can vary over temperature and individual boards due to tolerance of on-board reset generators and time bases.
If you need to know the total boot time from a cold/warm reset until the kernel is running you should take the time below and add to the time listed in Boot time - Summary.
| iMX8M Mini | iMX8M Nano | iMX8M | iMX6 Quad | iMX6 DualLite | iMX6 SoloX | iMX6 UltraLite | iMX7 Dual COM | iMX7 Dual uCOM | iMX7ULP | |
|---|---|---|---|---|---|---|---|---|---|---|
| Cold reset | 65 | 65 | 278 | 584 | 584 | 526 | 537 | 500 | 276 | 515 |
| Warm reset | 350 | 457 | 251 | 252 | 252 | 200 | 238 | 233 | 134 | 645 |
Cold reset
Cold reset is the same as switching on power to the board. The time is measured from valid level on VIN until positive edge on RESET_OUT.
Warm reset
Warm reset could be triggered from software or if a reset button is pressed. The time is measured from positive edge on RESET_IN until positive edge on RESET_OUT (except for the iMX8M Mini/Nano uCOM where it is negative edge on RESET_IN until positive edge on RESET_OUT).