1.4.1.5 MPU Bootloader Memory Layout
MPU Bootloader Persistent Storage Layout
For SD/eMMC media:
- The SD/eMMC media uses FAT-FS file system to store the Bootloader, Application and AT91bootstrap images
For NAND/Serial Flash media:
The placement of the AT91bootstrap, Bootloader and the application in Flash memory should be such that the application will not overwrite the Bootloader/AT91bootstrap, and the Bootloader can properly program the application when it is downloaded.
-
The application code can be placed anywhere after the bootloader end address. The application start address should be aligned to Erase Unit Size of the device.
-
As the Bootloader code requires the application start address to be mentioned at compile time, it should match in both the application and bootloader
-
The size of application image stores into Metadata region (address: 0x00180000) in the Flash memory

MPU Bootloader Execution Memory Layout
The following table shows Bootloader and Application start address in DDR memory for all MPU devices.
| Devices | Bootloader | Application |
|---|---|---|
| SAM9X75 | 0x23F00000 | 0x21000000 |
| SAMA7D65 | 0x66F00000 | 0x61000000 |
For example, SAM9X75 DDR execution memory layout is shown in the diagram as below.

