The SAMA5D3-XPLD board consists of an ATSAMA5D36 Cortex-A5 microcontroller, 128kiB of SRAM, 256MiB of RAM and 256MiB of NAND flash. It has connectors for Ethernet, LCD, USB and other expansion boards as well as an SD card slot.
For typical eCos development it is expected that ROMRAM startup type applications will be downloaded and debugged via a hardware debugger (JTAG) attached to connector J24. Use of a hardware debugging interface avoids the requirement for a debug monitor application to be present on the platform. However, if required, a RedBoot image can be programmed into the onboard NAND flash to provide an interactive bootloader environment. When using a GDB stubs monitor it is then possible to download and debug eCos RAM startup applications via the gdb debugger over USB (using the TTL debug channel) or Ethernet.
The bootstrap options for the SAMA5D3x parts are documented in the CPU variant documentation. How the CPU boots depends on the BMS signal. The SAMA5D3 Xplained has a Pull-Up on the CPU BMS pin so will default to BMS_BIT=0, resulting in the RomBOOT, on-chip, first-level boot loader being executed.
Note: The Atmel SAMA5D3 Xplained is pre-installed with example application software. The board is supplied with jumper JP5 (“NAND CS”) closed, which causes the board to boot using its factory-programmed NAND-based boot loader and then to the sample application image. It is necessary to overwrite these images in order to place RedBoot or any other application on the NAND flash.
The board port is intended to work with GNU tools configured for an arm-eabi target. The original port was done using arm-eabi-gcc version 4.7.3e, arm-eabi-gdb version 7.6.1, and binutils version 2.23.2.