SAMA5D3X-CM

SAMA5D3X-CM is a System-on-module (SoM) board in SODIMM204 format designed for embedded applications. SAMA5D3X-CM is using the Microchip (ATMEL) ATSAMA5D3X CPU with a CORTEX-A5 CPU running at 536MHz Product Info: https://ronetix.at/product/sama5d3x-cm-cpu-module-with-atmel-sama5d3-series Information about at91bootstrap, U-BOOT, Linux can be found here: https://www.linux4sam.org/bin/view/Linux4SAM/Sama5d3xekMainPage

Building at91bootstrap - second level bootloader for SAMA5D3X-CM

This bootloader is based on https://github.com/linux4sam/at91bootstrap, branch at91bootstrap-3.x

Setup the cross-compiler and CPU architecture

$ export ARCH=arm
$ export CROSS_COMPILE=/opt/cross/arm-ronetix-eabi-8.3.0/bin/arm-ronetix-eabi-

Clone the latest revision of the repo

$ git clone https://github.com/ronetix/at91bootstrap.git -b at91bootstrap-3.10.4_rnx
$ cd at91bootstrap

Configure and build

$ make sama5d3x_cm_nf_uboot_defconfig
$ make

Alternative: Configure and build with GPIO test

This requires a special prepared Ronetix's carrier board with shorted pin pairs. Used for production tests.

$ make sama5d3x_cm_gpio_test_defconfig
$ make

Build Results

File Name	Description
binaries/at91bootstrap.bin	BIN image, should be programmed at address 0x0
binaries/at91bootstrap.elf	ELF image used for JTAG debugging

Building Buildroot - a simple Linux System for SAMA5D3X-CM

Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation.
The home page of Buildroot is: https://buildroot.org
The Buildroot user manual can help you better understand how Buildroot works: http://www.buildroot.net/downloads/manual/manual.html
The Buildroot for SAMA5D3x is maintained by Microchip: https://www.linux4sam.org/bin/view/Linux4SAM/BuildRoot

Buildroot can build:

• at91bootstrap
• U-BOOT
• Linux Kernel
• A cross-compiler
• Root filesystems of different types

Prerequisites

Host build system should be a Linux system with necessary software installed: http://buildroot.uclibc.org/downloads/manual/manual.html#requirement
In addition to these required packages, you should also install libssl-dev:

$ sudo apt-get install libssl1.0-dev

or, depending on your host distribution:

$ sudo apt-get install libssl-dev

Get sources

$ mkdir buildroot-ronetix
$ cd buildroot-ronetix
$ git clone https://github.com/linux4microchip/buildroot-mchp.git
$ git clone https://github.com/ronetix/br2-external-ronetix.git

$ cd buildroot-mchp
$ git switch -c linux4microchip-2026.04 linux4microchip-2026.04

Build

$ make BR2_EXTERNAL=../br2-external-ronetix sama5d3x_cm_defconfig
$ make

Once compilation is done, the images have been generated in: ./output/image:

• at91bootstrap.bin
• rootfs.tar
• u-boot.bin
• u-boot-spl.bin
• zImage
• sama5d31ek.dtb
• sama5d33ek.dtb
• sama5d34ek.dtb
• sama5d35ek.dtb
• sama5d36ek.dtb
• rootfs.ubi
• rootfs.ubifs

The SAM-BA programming tool (used in the "Programming with SAM-BA 3.x" section below) is also built automatically by this defconfig and installed at:

• ./output/host/bin/sam-ba

Customizing Buildroot

AT91Bootstrap

$ make at91bootstrap3-menuconfig

U-BOOT

$ make uboot-menuconfig

Linux Kernel

$ make linux-menuconfig

RootFs

$ make menuconfig

Programming images

SAM-BA tool or PEEDI JTAG Flash Programmer can be used for programming the images into the NAND Flash.
All images should be programmed with 8-bit ECC.

Address	Image	Note
0x00000000	boot.bin	at91bootstrap, programmed with header 0xc0304405
0x00040000	u-boot.bin	U-BOOT, third level bootloader
0x00180000	sama5d35ek.dtb	Device tree for Linux Kernel
0x00200000	zImage	Linux Kernel
0x00F80000	rootfs.ubi	Root file system

Programming with SAM-BA 3.x

$ sam-ba -p usb -b sama5d3-ek -a lowlevel
$ sam-ba -p usb -b sama5d3-ek -a nandflash -c erase
$ sam-ba -p usb -b sama5d3-ek -a nandflash -c writeboot:boot.bin
$ sam-ba -p usb -b sama5d3-ek -a nandflash:1:8:0xc0304405 -c write:u-boot.bin:0x40000
$ sam-ba -p usb -b sama5d3-ek -a nandflash:1:8:0xc0304405 -c write:sama5d35ek.dtb:0x180000
$ sam-ba -p usb -b sama5d3-ek -a nandflash:1:8:0xc0304405 -c write:zImage:0x200000
$ sam-ba -p usb -b sama5d3-ek -a nandflash:1:8:0xc0304405 -c write:rootfs.ubi:0xF80000

More information about SAM-BA 3.x can be found here:
https://www.linux4sam.org/bin/view/Linux4SAM/Samba3Subsections