i.MX8 - iMX8MEVK - Getting Started - Selecting Boot Options
Boot Loading Options
The i.MX8M Evaluation Kit provides two switches in order to set the boot configurations according to your needs. You can see both switches on the following picture:
Where the one surrounded by a red square is the SW801 switch and the one surrounded by a yellow square is the SW802 switch.
- SW802: This switch allows to configure the boot source by selecting one of the following options:
- Boot From Fuses: The i.MX8M Applications Processor can be the set as a boot configuration. This can be made established via eFUSE, a dynamic real-time reprogramming technology of computer chips.
- Serial Downloader: The i.MX8M downloads a program image from a USB connection.
- Internal Boot: For development. The boot mode is selected by configuring the SW801 switch.
- Reserved.
- SW801: This switch allows to configure the boot mode by selecting one of the following options:
- Boot from EMMC.
- Boot from SD2.
The method used to determine where the processor finds its boot information is from two dedicated BOOT MODE pins. In the following table you can see how to configure each mode on SW802:
| Boot Source | PIN1 | PIN2 |
|---|---|---|
| Boot from fuses | OFF | OFF |
| Serial Downloader | OFF | ON |
| Internal Boot | ON | OFF |
| Reserved | ON | ON |
For example, if the method of determining the bootable source code is selected to be from the switch, then the developer must set the SW802: PIN1 to ON, PIN2 to OFF, and the four i.MX8M pins of the SW801 must be set on the EVK board by considering the information present in the following table:
| BOOT Configuration | PIN1 | PIN2 | PIN3 | PIN4 |
|---|---|---|---|---|
| Boot from EMMC | OFF | OFF | ON | OFF | |||
| Boot from SD2 | ON | ON | OFF | OFF |
This is how the physical switch SW801 should be set in order to boot from EMMC:
And this is how the physical switch SW801 should be set to boot from SD2:
Operating System Loading Options
EMMC
In order to boot from the EMMC device, be sure that the Boot Configuration Switch is set to 0010. The board is preloaded with Android 8.1 and this OS will be loaded after plugging in the power adapter.
USB Boot
This option requires a Bootable USB stick and a Serial Console Cable, refer to iMX8 Software Support section to download a pre-built image or create your own image with the instructions provided in the Custom Image section.
Instructions to setting up the USB Boot:
- Connect the iMX8MQ board to a host machine with the Serial Console Cable.
- Start any serial console (i.e minicom or term)
- Power on the board, the console will display the U-boot start-up screen.
- Press any key on your keyboard to stop the boot sequence, this will display the U-Boot console.
- Change the Boot Device with the following command:
setenv boot_targets usb0
- If you do not want to repeat this commands, you can save the selected Boot Device with this command:
saveenv
- Continue the Boot sequence by typing the next command:
boot
After the previous instructions, the board will boot from the USB stick