urjtag/jtag/doc

This diff files add:

1) EJTAG support. It supply ability to flash almost ALL EJTAG-capable boards (ARM, MIPS).

It is not needed to search BSDL sescriptors. it uses STANDARD path to access flash.

For new CPU it is needed just add data files wich can be authomatically

generated, but jtag-tools originally used this files and auto generation for EJTAG-capable

CPUs is not wroted. Anybody can wrote this code.



EJTAG driver written by Marek Marek Michalkiewicz <marekm@amelek.gda.pl>, 2005

under GPL http://www.amelek.gda.pl/rtl8181/jtag/



2) data files for very different EJTAG capable MIPS CPUs in file data-add.diff

Realtek RTL8181, RTL8186, Admtek ADM5120, Atheros AR2312, TI AR7, Brecis (PMC-Sierra) MSP2006.

anybody can create files for nes CPUs using this files as template.

Truly say, it is needed to change just

"instruction length" and "endian" strings.

Instruction length can be given by "detect" command:

jtag> detect

IR length: 5

Chain length: 1

Device Id: 0001-0000001000000010-00101110000-1

           ^^^^ ^^^^^^^^^^^^^^^^ ^^^^^^^^^^^

--->>>>    step-PARTS           -MANUFACTURER



3) address-support.diff contains support for non-zero flash address.

Different CPUs use different flash addresses.



Example: TI AR7 (famouse ADSL modems) uses 0x30000000

another MIPS CPUs uses 0x3fc00000 (standard for MIPS32 boards).

0x1------- is for 8bit access to flash (example: 0x1fc00000)

0x3------- is for 16-bit access to flash (example: 0x3fc00000)

0x5------- is for 32-bit access to flash (example: 0x5fc00000)

length depends on flash. It is possible to try any from this address regions.

Many CPUs map flash to all of this addresses.



So, for EJTAG non-zero flash address support IS NEEDED. Unfortunetly, ejtag-tools

not maintained by owner and this patch is not implemented more than 2 years.

But, i think, it is not needed to create new sourceforge project.



For success flashing it is needed to take into attention:

in file /libbrux/flash/amd.c there are strings:

	o = 1; /* Heuristic */

Flash can be connected to board using switch in address. In some cases it is needed

to add 1 to this digit. For example, MSP2006 boards uses amd_flash_autodetect8 

with o = 1. And AR7 uses o = 0.



4) example of successful flashing using EJTAG: http://forum.openwrt.org/viewtopic.php?id=4191



Patch do not conflicts with another patches.

it 

1)adds /src/bus/ejtag.c file

2) register this file in /src/bus/buses.c buses.h makefile.am

3) removes one check from /src/tap/parport/ppdev.c

4) change in flash.c is not needed, but can speedup flashing. It just exclude "printf" from cycle.

5) comment two strings in libbrux/flash/detectflash.c

it is not needed

6) add non-zero flash address support to  libbrux/flash/jedec.c and amd.c

i wonder why this is not added to CVS tree. This patch was given by different peoples many times.