The bootloader, one of the key software components included in the BSP, completes the required hardware initialization to run operating system images. The boot mode determines the location of the primary bootloader and is selected from the S1 dipswitch on the underside of the Carrier Board.

The Boot Switch S1 should only be modified with the i.MX7 completely powered off and disconnected from a power supply. 

Set the S1 dipswitch correspondingly:

SD Card

 Advanced SD/MMC Boot Configurations

SD/MMC Boot Jumper Configuration

J81+2 (Default)Select to boot via normal speed SD/MMC
2+3Select to boot via high speed SD/MMC

eMMC

NAND

 Advanced NAND Boot Configurations

NAND Boot Jumper Configuration

J211+2Select 128 pages per block when booting from NAND

2+3

(Default)

Select 64 pages in block when booting from NAND

QSPI NOR Flash