i.MX31 - 3 Stack
There are two boot modes for IMX31PDK. In Internal Boot mode, the processor will execute an address from internal memory, and in External Boot mode the processor will execute an address from a external memory properly configured. This modes can be configured setting the values of dip switch SW5-SW10 shown in image below.
Debug board. Top view.External Boot from Flash
In this mode, the processor will execute an address into a external flash (NAND).
If there is a bootloader saved in the right place in flash, it will be executed and the system will start. If there are a kernel image and a root file system saved configured, the operational system will start.
The values for the IMX31PDK dip switches programming the boot sequence are show in table below.
| SW5 | SW6 | SW7 | SW8 | SW9 | SW10 | |
| Internal Boot (programming flash) | 0 | 0 | 0 | 0 | 0 | 0 |
| External Boot from Flash | 0 | 1 | 0 | 0 | 0 | 0 |
Internal Boot
The Internal Boot mode enables ATK to communicate with processor and perform the writing of images into flash (bootloader image, kernel image and root file system image).
