Hello everyone,
let me explain you my situation first so that you understand what I want to achieve:
I am currently trying to read out the NAND Flash from a chip that I have here. First I tried to use the BusPirate v4 to do so. Unfortunately it didn't work, I had several issues with flashrom and my other attempts to communicate with the SPI NAND Flash didn't work either.
So I searched for an other option and I saw that I can read out my NAND Flash via JTAG as well. Apparently there is a readmem command, so I wanted to try that out (at this point I don't really care much if it takes way longer like that because I am stagnating for weeks at the same point).
I connected my BusBlaster v4.1a with the corresponding pins and my first attempt was with UrJTAG.
This is the result:
UrJTAG 0.10 #1502
Copyright (C) 2002, 2003 ETC s.r.o.
Copyright (C) 2007, 2008, 2009 Kolja Waschk and the respective authors
UrJTAG is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
There is absolutely no warranty for UrJTAG.
WARNING: UrJTAG may damage your hardware!
Type "quit" to exit, "help" for help.
jtag> cable jtagkey pid=0x6010 vid=0x0403 interface=0
Connected to libftd2xx driver.
jtag> detect
Warning: TDO seems to be stuck at 1
jtag>
I looked that up, first I thought I may have connected something wrong, unfortunately I found several posts about the exact same problem. I didn't find a solution though.
So I got curious if it's maybe a problem with UrJTAG so I tried out to access JTAG via OpenOCD.
This is what I got:
~/openocd/tcl$ openocd -f interface/ftdi/dp_busblaster.cfg -f target/qualcomm_qca4531.cfg
Open On-Chip Debugger 0.10.0+dev-00924-g16496488 (2019-08-22-10:23)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
Info : If you need SWD support, flash KT-Link buffer from https://github.com/bharrisau/busblaster
and use dp_busblaster_kt-link.cfg instead
adapter speed: 2000 kHz
Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
qca4531_ddr2_550_550_init
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 2000 kHz
Error: JTAG scan chain interrogation failed: all ones
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: qca4531.cpu: IR capture error; saw 0x1f not 0x01
Warn : Bypassing JTAG setup events due to errors
Error: isa info not available, failed to read cp0 config register: 0
Error: The 'mww' command must be used after 'init'.
Error executing event halted on target qca4531.cpu:
Info : Listening on port 3333 for gdb connections
I have no idea if I am doing something really wrong of if the chip or the BBv4.1a is broken or something else.
Does anyone have an idea what I can try out else or what I can do to fix these issues?