thanks so far - I got it running (with nsh support) by loading it via ftftp from u-boot.
Your documentation is really great!
So my next steps will be to get the framebuffer / lcd driver up and running.
If I understand you right, I don't have change something at the memory configuration?
Looking forward to see my first picture :)
After I got this running I have to setup network and usb (host) for HID and mass storage.
Have a great weekend,
On Friday, September 19, 2014 6:47 PM, "email@example.com [nuttx]" <***@yahoogroups.com> wrote:
Post by Dieter Kiermaier firstname.lastname@example.org [nuttx]
Sorry, forgot to ask one more thing - am I right, that the default configuration for the Xplained kit is not using any external memory?
It looks like because there is no CS configured?
Yes, in fact the basic code runs from SDRAM. But all code that runs in SDRAM has to be loaded by a bootloader (because something has to initialize the SDRAM before you an load the code into it). Therefore, there is no need to initialize SDRAM from NuttX (In fact, you can't re-initialize SDRAM if you are running from it without crashing). So NuttX, like Linux, simply leaves the external memory configuration in place as it was set up by the bootloader.
For the case of the SAMA5D-Xplained, there are not many boot options. I booted from NOR flash on the SAMA5D3x-EK but the SAMA5D-Xplained has no NOR flash so you have to run out of SDRAM. The only question is then what media you store the binary on before booting from SDRAM. There are several options: NAND, serial flash, or an SD card (and others I think).
I did most testing with nuttx.bin on an SD card using the U-Boot bootloader. These are the commands that I used to boot NuttX from the SD card:
U-Boot> fatload mmc 0 0x20008000 nuttx.bin
U-Boot> go 0x20008040
This is all described in configs/sama5d-xplained/README.txt.
The SAMA5D4-EK does not have NOR FLASH either. In that case, I wrote my own tiny bootloader that you can find at configs/sama5d4-ek/dramboot. I put this on the SD card as boot.bin. You an then coerce the ROM boot loader to boot from the program called boot.bin on an SD card instead of U-Boot in NAND.
The dramboot program loads into internal SRAM at boot time, initializes SDRAM, then loads nuttx.hex over serial into SDRAM, and starts it (or it can be configured to just wait so that you can break in with a debugger after the code has been loaded into SDRAM. Then you can set breakpoints and single step into NuttX). I found this very handy. I imagine that dramboot could be ported to the SAMA5D Xplained without too much effort.
NuttX also has verified support for the NAND on the SAMA5D3 boards. However, there is no proper NAND FLASH file system available now.