README

This sample program is a boot-loader with in-memory update of the kernel image
(chain boot). When the sample is running, you can send an other kernel*.img
file via the local network to your Raspberry Pi and automatically start it. The
kernel image is not written out to the SD card. The boot-loader has two user
interfaces, a HTTP-based web front-end and a TFTP file server daemon.

The boot-loader does not implement any authorization method (e.g. a password).
Be sure to be the only user on your local network, who has access to it!


USING HTTP

Open the following URL in a web browser on your host computer, enter a kernel
image file to be uploaded (kernel*.img) and press the "Boot now!" button.
ip_address is the IP address of your Raspberry Pi and is displayed on its
screen.

	http://ip_address:8080/


USING TFTP

You need a TFTP client installed on your host computer to use this. Enter the
following command to send the kernel image:

	tftp -m binary ip_address -c put kernel.img

ip_address is the IP address of your Raspberry Pi and is displayed on its
screen. The file name of the kernel image may be slightly different, depending
on your Circle project settings. Some TFTP clients do not allow to specify all
options on the command line. You may have to specify the "binary" and "put"
commands manually behind the tftp> prompt.


SOME NOTES

If you want to include the boot-loader support into your own application, please
note that:

* The chain boot mechanism is not supported in multi-core applications.

* The accelerated graphics and HDMI sound support cannot be restored after
  chain boot, if used before. There may be problems with the Act LED too.
  That's why it is not used in this bootloader.

* Some devices are not reset in the destructors of their driver classes.
  This may cause problems with some devices. Please report such issues.
  The devices used in this sample should work in any way.

* The source file main.cpp of this sample is slightly different from that,
  which is used in other sample programs.
