| Atmel SAMA5D3 Xplained board |
| ============================ |
| |
| This document explains how to set up a basic Buildroot system on the |
| Atmel SAMA5D3 Xplained board, whose main site is |
| http://www.atmel.com/tools/ATSAMA5D3-XPLD.aspx. Additional details can |
| also be found on the http://www.at91.com/linux4sam/bin/view/Linux4SAM/ |
| web site. |
| |
| Note that the default Buildroot configuration is prepared to boot from |
| an SD card: the first stage bootloader, second stage bootloader, |
| kernel image and root filesystem are all located on the SD card. Some |
| adjustements in the bootloader configuration will be needed to boot |
| from NAND flash. |
| |
| Configuring and building Buildroot |
| ---------------------------------- |
| |
| make atmel_xplained_defconfig |
| make |
| |
| Preparing the SD card |
| --------------------- |
| |
| The SD card must be partitionned with at least two partitions: one |
| FAT16 partition for the bootloaders, kernel image and Device Tree |
| blob, and one ext4 partition for the root filesystem. To partition the |
| SD card: |
| |
| sudo sfdisk -uM /dev/mmcblk0 <<EOF |
| ,64,6 |
| ; |
| EOF |
| |
| This creates a 64 MB partition for the FAT16 filesystem (type 6) and |
| uses the rest for the ext4 filesystem used for the root filesystem. |
| |
| Then, format both partitions: |
| |
| sudo mkfs.msdos -n boot /dev/mmcblk0p1 |
| sudo mkfs.ext4 -L rootfs -O ^huge_file /dev/mmcblk0p2 |
| |
| Note: the -O ^huge_file option is needed to avoid enabling the huge |
| files features of ext4 (to support files larges than 2 TB), which |
| needs the kernel option CONFIG_LBDAF to be enabled. |
| |
| Mount both partitions (if not done automatically by your system): |
| |
| sudo mount /dev/mmcblk0p1 /media/boot |
| sudo mount /dev/mmcblk0p2 /media/rootfs |
| |
| Copy the bootloaders, kernel image and Device Tree blob to the first |
| partition: |
| |
| cp output/images/uboot-spl.bin /media/boot/boot.bin |
| cp output/images/u-boot.img /media/boot/u-boot.img |
| cp output/images/zImage /media/boot/zImage |
| cp output/images/at91-sama5d3_xplained.dtb /media/boot/at91-sama5d3_xplained.dtb |
| |
| Extract the root filesystem to the second partition: |
| |
| sudo tar -C /media/rootfs -xf output/images/rootfs.tar |
| |
| Unmount both partitions: |
| |
| sudo umount /media/boot |
| sudo umount /media/rootfs |
| |
| Insert your SD card in your Xplained board, and enjoy. The default |
| U-Boot environment will properly load the kernel and Device Tree blob |
| from the first partition of the SD card, so everything works |
| automatically. |
| |