====== NvFlash ====== nvflash is a utility provided by Nvidia for flashing Tegra devices. Nvflash runs on a host PC and communicates with the Tegra system (the AC100 in our case) through a dedicated USB port (the mini USB port on the AC100). nvflash is distributed by nvidia as a binary only. Sources are not available and the communication protocol in not publicly documented.
====== Installing nvflash ======
==== From the nvidia tegra developper site ====

nvflash is distributed as part of the Linux4Tegra Development kit. available here: http://developer.nvidia.com/tegra-250-tango-development-kits

The following commands will install nvflash in ~/tools/ldk/bootloader folder:

<code>
$ mkdir ~/tools/
$ wget http://developer.download.nvidia.com/assets/mobile/files/tegra-linux-12.alpha.1.0.tar.gz
$ tar xf tegra-linux-12.alpha.1.0.tar.gz 
</code>

Two files are useful:
  * ~/tools/ldk/bootloader/nvflash: the nvflash utility itself
  * ~/tools/ldk/bootloader/harmony/fastboot.bin, a simple bootloader which is downloaded on the Tegra CPU to manage further communication with nvflash

In order to be able to run nvflash as a normal user, you need to install an udev rule file:

<code>
$ sudo -i
$ cat > /etc/udev/rules.d/60-nvflash.rules <<END
# nvflash support for Nvidia Tegra systems attached to USB
SUBSYSTEM=="usb", ATTR{idVendor}=="0955", ATTR{idProduct}=="7820", MODE="0660", GROUP="plugdev"
END
</code>

This last step is optional, but without doing it you will have to run nvflash as root.

==== Debian/Ubuntu Package ====

Without any clear usage and redistribution license, nvflash cannot be distributed as a standard package. 
An installer package is available from here: http://share.grandou.net/debian/nvflash

Here is how to install it:

<code>
$ cd /tmp
$ wget http://share.grandou.net/debian/nvflash/nvflash_20110628-2_all.deb 
$ sudo dpkg -i nvflash_20110628-2_all.deb
</code>

nvflash is installed in /usr/bin/nvflash, and so can be run directly from your shell
The bootloader is installed here: /usr/lib/nvflash/bootloader.bin

The package takes care of installing an udev rules, allowing you to run nvflash as a normal user.


====== nvflash setup ======

  - Powerdown your AC100
  - Connect the USB cable between your AC100 and the host PC
  - press CTRL and ESC keys, and while maintaining them pressed, powerup your AC100
  - the AC100 power white LED should light on, the screen remains switched off
  - download the bootloader into the CPU RAM, on your host PC, type:
<code>
$ nvflash --bl /usr/lib/nvflash/fastboot.bin --sync
</code>

Note: adapt the command with real path of your fastboot.bin

Now the AC100 is ready to accept commands from nvflash


====== nvflash commands ======

Write the image <filename> partition <N> of your AC100:

<code>$ nvflash -r --download <N> <filename></code>

Read the partition <N> from the AC100 to the file <filename>:

<code>$ nvflash -r --read <N> <filename></code>

For a complete description of nvflash commands:

<code>$ nvflash --help</code>