11:35 <Deneb> hi, I am starting out with hardware debugging and have been experimenting with JTAGEnum. Moving on to the next step, I would like to ask the opinion on a budget adapter for openocd.

11:40 <Deneb> I have come across mention of a number of device such as Shakira and Attify which I can't find available to purchase anywhere in the UK. I also found mention of Jlink, but this is very expensive although there are cheap clones on eBay. The other options I was thinking of was maybe a Jtagulator. I do have a Buspirate somewhere, although I read these are reather slow?

11:40 <Deneb> So I was wondering what device to get. Ideally it should be able to access UART, JTAG and SWD.

11:42 <Deneb> There appear to be a bunch of other jtage/programmer devices on eBay, but since I know nothing about them I thought I would ask since I don't want to be wasting money on something that will not work, or work very badly!

11:46 <PaulFertser> Deneb: jlink edu should be an affordable option.

11:47 <PaulFertser> Deneb: or something FTDI-based such as Olimex adapter. Or TUMPA (not lite).

11:49 <PaulFertser> Deneb: if you buy some eval board, e.g. ST disco or Nucleo then you'll have a suitable adapter integrated.

11:50 <Deneb> I just found an Olimx board on eBay UK, but it looks a bit old: Olimex ARM-USB-OCD-H, 3 In 1 USB JTAG Debugger, USB to RS232 Virtual Port

11:51 <Deneb> What about Bus Blaster? Just found that and its FTDI bvased?

11:52 <Deneb> Looking at those dev boards you mentioned as well...

11:53 <PaulFertser> Deneb: BB is a good choice too, but probably its CPLD is not as sturdy.

11:54 <PaulFertser> Deneb: what target hardware do you plan to debug?

11:54 <Deneb> Nucleo boards seem readily available. Seem to be a large variety of them.

11:55 <PaulFertser> Deneb: of course, if you're interested in MCU development that's a rather nice option.

11:56 <Deneb> As regards what I plan to debug, initially I want to learn on the Pi and a couple of other 5v/3.3V devices I have here, but I would like the flexibility of working with lower voltages as well, which is what initially attracted me to the Jtagulator. It supports down to 1.5V, but so does this BusBlaster board which is half the cost.

11:57 <PaulFertser> Deneb: the Pi as in raspberrypi or as in rp2040?

11:58 <Deneb> Some references say that the Jtagulator can't be used as an interface tjhough, its only for identifying pins. I am also unsaure whether the boards sold on AliExress are OK

11:58 <PaulFertser> Yes, OpenOCD doesn't support jtagulator.

11:58 <PaulFertser> You are unlikely to see anything lower than 1.8 V in common use.

11:59 <Deneb> PaulFertser: at the moment, I have successdfully used Jtagenum to identuify the pins on a Pi2. I was going to experiment with the Pico, but this has SWP instead of jtag but Jtagenum does not support this.

12:00 <Deneb> seems a shame that the jtagulator does not provide both functions. It already has the hardware?

12:00 <PaulFertser> Deneb: I have no idea how come nobody contributed support to use jtagulator as a debug interface for OpenOCD.

12:01 <PaulFertser> Deneb: if you're new to low level development I suggest to start with MCUs, and STM32 families are nice and popular, so you can find plenty of library options, blog posts, advice etc.

12:04 <Deneb> ooh, then again it seems Joe Grand might have added that feature: https://www.youtube.com/watch?v=NWTNH1RgUZc

12:04 <Deneb> Just found that video...

12:06 <Deneb> noted, re: STM32 families. I am looking to be able to pull off and examine firmware on devices as well. I have already been looking into tools to analyse binaries.

12:09 <Deneb> I did wonder whether Jtagenum on the arduino could be used with OpenOcd? Or indeed whether that support can be added.

12:09 <Deneb> PaulFertser: thanks for you insight.

12:09 <Deneb> *your

12:12 <PaulFertser> Deneb: good luck with your studies!

12:12 <Deneb> thnx

16:05 <Deneb> hi, I am trying to get going with openocd. I have dug out a Buspirate and confirmed that the firmeware has jtag support (community firmweare 7.1, bootloader 4.5), however I am having difficulty with the next steps.

16:05 <Deneb> have created a Buspirate.cfg file and run openocd weith: openocd -f Buspirate.cfg

16:05 <Deneb> getting some errors:

16:05 <Deneb> Error: JTAG scan chain interrogation failed: all ones

16:05 <Deneb> Error: Trying to use configured scan chain anyway...

16:05 <Deneb> Error: Check JTAG interface, timings, target power, etc.

17:23 <Deneb> Ok, I had a wiring error so now I have JTAG tap: bcm2837.cpu tap/device found: 0x4ba00477

17:24 <Deneb> however, I am getting JTAG-DP STICKY ERROR. What does this mean please?

17:24 <Deneb> examination of the BCM2387 fails and I cannot connect to the listening port 3333

18:08 <PaulFertser> borneoa_: can't do it today, sorry, too much unrelated stress so I'll try to concentrate on that tomorrow.

18:09 <PaulFertser> Deneb: you should probably try reading some raspberrypi debugging blogposts. It might be that you need some noidle kernel parameter and probably something else too.

18:10 <borneoa_> PaulFertser: no problem

18:17 <Deneb> PaulFertser: thanks. Made some progress from earlier but can't get past this problem for now. The openocd output shows it has found a BCM2387 with the correct ID but the next messages say examination failed. I had a look at the Pi hardware with cat /proc/cpuinfo and it reckions it has a BCM2835. So I created a pi2.cfg file modified for the BCM2385 and it now says that the ID is wrong...

18:17 <Deneb> anyway, still searching online for answers....