__  .__
   ___________   _____/  |_|  |__
  / ___\_  __ \_/ __ \   __\  |  \
 / /_/  >  | \/\  ___/|  | |   Y  \
 \___  /|__|    \___  >__| |___|  /
/_____/             \/          \/


Author: Quentin Casasnovas
Licence: GPL2
Version: 0.1

1. Description
~~~~~~~~~~~~~~
  This small utility permits to read/write directly from/to a AHB/APB Bus in a
embedded device using gaisler Greth ethernet IP. This allow you for example to
dump RAM region, write to a particular register in an IP, or even write a
complete file to memory.

  This works originated from my final internship at Scaleo Chip, a fabless
semiconductor company. I was working on a Linux-SMP kernel on leon3
architecture and needed a way to dump the kernel directly to RAM. Before
writing this utility, I had to transfer it using the serial port, which takes
for ever if you need to transfer the kernel multiple times a day...

  So this programms simply implements the EDCL protocol developped by Gaisler,
and speacks directly to a greth IP to read/write on the bus. This could be a
good start if you're planning on writing a free debugger for leon processors,
feel free to let me know if you start such project, I'll be glad to work on it.

2. Usage
~~~~~~~~

  I'll copy/paste here the usage from the binary itself, I think it's self
explanatory. If there's something you don't understand, feel free to ask me,
I'll probably add the explanations here too.

Usage: ./greth read --ip/-i ip_address
       	       [--memory-address/-m memory_address] (default to 0x40000000)
	       [--length/-l length] (default to 4)
	       [--big-endian/-b]
	       [--verbose/-v]
or: 	./greth write --ip/-i ip_address
		[--memory-address/-m memory_address] (default to 0x40000000)
	     	[[--file/-f filename]/[--word/-w word_value]] (default to -w 0x1234CAFE)
		[--check-copy/-c] (not implemented yet)
		[--big-endian/-b]
		[--verbose/-v]
or: 	./greth help

3. Documentation
~~~~~~~~~~~~~~~~
  The code should be documented enough for anyone who knows a bit of C. If
you'd like to read the documentation for the EDCL protocol from gaisler, it's
described in their grip pdf documentation file, in the greth chapter (you can
find it on their website http://www.gaisler.com in the download area).

4. Miscellaneous
~~~~~~~~~~~~~~~~
  The ascii font used in INSTALL and README files is "graffiti" ans has been
generated with the online ascii generator present at
http://www.network-science.de/ascii/