I'm using a Blue Pill board (STM32F103CB with 128kB of flash according to st-info --probe) via a clone ST-Link/V2 like this one. I've also tested using a genuine ST-Link/V2 like this one. I get the same result, described below, with both programmers.
My system is Linux (Debian LXDE) and I've installed OpenOCD from Liviu Ionescu's releases here.
My OpenOCD installation is working. As well as the Blue Pill I have a ST-Nucleo-F103RB board, and I can connect to it using OpenOCD. The command
openocd -f board/st_nucleo_f103rb.cfg
using the standard .cfg file that ships with OpenOCD gives
Open On-Chip Debugger 0.10.0
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
adapter speed: 1000 kHz
adapter_nsrst_delay: 100
none separate
srst_only separate srst_nogate srst_open_drain connect_deassert_srst
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : clock speed 950 kHz
Info : STLINK v2 JTAG v29 API v2 SWIM v18 VID 0x0483 PID 0x374B
Info : using stlink api v2
Info : Target voltage: 3.271135
Info : stm32f1x.cpu: hardware has 6 breakpoints, 4 watchpoints
But I still haven't managed to connect to my Blue Pill using the ST-Link/V2 programmers. I've read everything I can find, including relevant sections of https://elinux.org/Category:OpenOCD and as much as I can personally digest of http://openocd.org/doc/. The following is where I've got to.
The .cfg file stm32f103c8_blue_pill.cfg doesn't work for me. It produces the output described below.
Based on what I've read I've prepared my own .cfg file at ../board/stm32f103.cfg. It says:
source [find interface/stlink.cfg]
transport select hla_swd
source [find target/stm32f1x.cfg]
#source [find board/stm32f103c8_blue_pill.cfg]
#reset_config srst_only
#reset_config none separate
Sources I've read suggest this should work, but it doesn't. Using my .cfg described above, it I can use either target/stm32f1x.cfg or board/stm32f103c7_blue_pill.cfg, and I still get the same output as described below. (In the case of both of those .cfg files I'm using the standard files, as shipped with OpenOCD.) I've tested with both of the reset_config variants shown above, and with neither. None of the combinations works.
The file interface/stlink.cfg that I'm using is modified. I've changed it to state the correct device_desc "ST-LINK/V2" and the correct vid_pid 0x0483 0x3748. (Both confirmed using lsusb.) So, ignoring commented lines, stlink.cfg reads
interface hla
hla_layout stlink
hla_device_desc "ST-LINK/V2"
hla_vid_pid 0x0483 0x3748
I've experimented with including the hla_serial of the programmer. Interestingly, lsusb can't find the full serial number. st-info --probe finds the serial number, but gives a slightly different number from the STLinkUpgrade firmware application. I've tried using both serial numbers. No difference.
Here's the command I give to OpenOCD:
openocd -s ~/stm32/openocd/scripts -f board/stm32f103.cfg
Notice that I have to set the path using -s for this command. With the ST-Nucleo-F103RB board, I don't have to do this. With the stm32f103.cfg file, however, if I don't set the path I get:
Error: Can't find board/stm32f103.cfg
in procedure 'script'
If I use the full command shown above, with -s to set the path, I get:
Open On-Chip Debugger 0.10.0
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
/[..]stm32/openocd/scripts/target/stm32f1x.cfg:47: Error: invalid command name "dap"
in procedure 'script'
at file "embedded:startup.tcl", line 60
at file "/[..]stm32/openocd/scripts/board/stm32f103.cfg", line 18
at file "/[..]stm32/openocd/scripts/target/stm32f1x.cfg", line 47
Here's the offending line 47 of stm32f1x.cfg:
dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu
I've searched for items on Stackoverflow/ similar about Error: invalid command name "dap". Using the OpenOCD documentation I understand that the dap create command exists, and roughly what it does. The most similar reported error I've found documented is at https://elinux.org/OpenOCD_Troubleshooting:_Invalid_Command_Name_JTAG, and the solution suggested there doesn't seem to be applicable because I'm not invoking interface/stlink.cfg from the command line.
I can't see what I'm doing wrong, and I'm now completely stuck. If someone can give me a steer I'd be really grateful. Sorry it's such a long post.