Build at91bootstrap

Last modified by Microchip on 2026/08/17 11:47

Get at91bootstrap Source Code

You can download the at91bootstrap source code from the at91bootstrap Git repository.

Fast Boot Default Configurations

The at91bootstrap program must be configured for Ultra-Fast Boot. Assuming you are at the at91bootstrap root directory, you will find a configs folder that contains several default configuration files. The first step is to configure a default configuration. Here are some default configurations dedicated to fast booting:

sam9x60_curiositynf_fb_defconfig
sam9x60_curiositysd_fb_defconfig
sama5d27_som1_eksd_fb_auto_defconfig
sama7d65_curiositysd1_fb_auto_defconfig

These configurations already enable almost all fast boot options except memory map configuration.

The default configuration includes:

Enable Fast Boot mode
Enable Fast Boot Operation mode
Enable Backup mode
Enable Shutdown Controller Support

See the "Configure Ultra-Fast Boot in aT91bootstrap KCONFIG" page for more details.

Default Configuration Example

Set the fast boot default config for the SAMA765 Curiosity board to boot using an SD™ card with Automatically Save and Load Snapshot Image mode.

$ make sama7d65_curiositysd1_fb_auto_defconfig

Configure at91bootstrap to Enable Fast Boot

To add more configuration options, type the following command:

$ make menuconfig

Enable Fast Boot Command

See the "Configure Ultra-Fast Boot in at91bootstrap KCONFIG" page for more detailed information.

Build Binary

Then you can build the at91bootstrap binary using the following command:

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-

If the building process is successful, the final .bin image is build/binaries/boot.bin.

Overriding the at91bootstrap

Now we can replace the bootloader stored in Non-Volatile Memory (NVM) with the new one.

To boot using the SD card, copy boot.bin to the SD card and replace the existing file.

For NAND flash boot, we can write a new at91bootstrap image and set the boot configuration with SAM-BA^® software.