Cannot Debug STM32 NUCLEO-H745ZI-Q

Using Platformio ide is impossible to debug the STM32 NUCLEO-H745ZI-Q. The code I’m trying to upload/debug is a simple led blinking Zephyr sample code, directly gotten from the Platformio samples library. I’m on Windows10

This is the platformio.ini

[env:nucleo_h745zi_q]
platform = ststm32
board = nucleo_h745zi_q
framework = zephyr
upload_protocol = stlink
debug_tool = stlink

And this is the console output that I’m getting:

PlatformIO: debug_tool = stlink

PlatformIO: Initializing remote target…

xPack OpenOCD x86_64 Open On-Chip Debugger 0.11.0+dev (2021-10-16-21:19)

Licensed under GNU GPL v2

For bug reports, read

OpenOCD: Bug Reporting

srst_only separate srst_nogate srst_open_drain connect_deassert_srst

Info : tcl server disabled

Info : telnet server disabled

Info : STLINK V3J2M1 (API v3) VID:PID 0483:374E

Info : Target voltage: 3.277815

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : clock speed 1000 kHz

Info : stlink_dap_op_connect(connect)

Info : SWD DPIDR 0x6ba02477

Info : stm32h7x.cpu0: Cortex-M7 r1p1 processor detected

Info : stm32h7x.cpu0: target has 8 breakpoints, 4 watchpoints

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Error: stm32h7x.cpu1 – clearing lockup after double fault

Polling target stm32h7x.cpu1 failed, trying to reexamine

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Info : gdb port disabled

Info : starting gdb server for stm32h7x.cpu0 on pipe

Info : starting gdb server for stm32h7x.cpu1 on pipe

Info : accepting ‘gdb’ connection from pipe

Info : Device: STM32H74x/75x

Info : flash size probed value 2048

Info : STM32H7 flash has dual banks

Info : Bank (0) size is 1024 kb, base address is 0x08000000

Info : Device: STM32H74x/75x

Info : flash size probed value 2048

Info : STM32H7 flash has dual banks

Info : Bank (1) size is 1024 kb, base address is 0x08100000

Info : New GDB Connection: 1, Target stm32h7x.cpu0, state: halted

Info : accepting ‘gdb’ connection from pipe

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (2) size is 1024 kb, base address is 0x08000000

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (3) size is 1024 kb, base address is 0x08100000

Info : New GDB Connection: 2, Target stm32h7x.cpu1, state: halted

Warn : keep_alive() was not invoked in the 1000 ms timelimit. GDB alive packet not sent! (1010 ms). Workaround: increase “set remotetimeout” in GDB

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: Failed to read memory at 0xfffff000

0xfffffffe in ?? ()

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001030 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

Info : Unable to match requested speed 4000 kHz, using 3300 kHz

Info : Unable to match requested speed 4000 kHz, using 3300 kHz

Warn : keep_alive() was not invoked in the 1000 ms timelimit. GDB alive packet not sent! (1013 ms). Workaround: increase “set remotetimeout” in GDB

Loading section rom_start, size 0x298 lma 0x8000000

Error: GDB missing ack(2) - assumed good

Loading section text, size 0x32d2 lma 0x8000298

Error: GDB missing ack(2) - assumed good

Loading section .ARM.exidx, size 0x8 lma 0x800356c

Error: GDB missing ack(2) - assumed good

Loading section initlevel, size 0x98 lma 0x8003574

Error: GDB missing ack(2) - assumed good

Loading section devices, size 0x168 lma 0x800360c

Error: GDB missing ack(2) - assumed good

Loading section sw_isr_table, size 0x4b0 lma 0x8003774

Error: GDB missing ack(2) - assumed good

Loading section device_handles, size 0x78 lma 0x8003c24

Error: GDB missing ack(2) - assumed good

Loading section rodata, size 0x318 lma 0x8003c9c

Error: GDB missing ack(2) - assumed good

Loading section datas, size 0x30 lma 0x8003fb4

Error: GDB missing ack(2) - assumed good

Loading section device_states, size 0x3c lma 0x8003fe4

Error: GDB missing ack(2) - assumed good

Error: GDB missing ack(2) - assumed good

Info : Padding image section 0 at 0x0800356a with 2 bytes

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

Start address 0x8001038, load size 16414

Error: GDB missing ack(2) - assumed good

Transfer rate: 5 KB/sec, 1641 bytes/write.

Error: GDB missing ack(2) - assumed good

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

Warn : negative reply, retrying

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

Warn : negative reply, retrying

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

Then the debugger hangs indefinitely.

It is worth noting that when using the older NUCLEO-F401RE everything works fine.

Thanks in advance.

That’s weird, looks like it’s in the system bootloader memory. Is the BOOT0 (and possible BOOT1) pin connected directly to GND? There might be a jumper on the board.

Hi Max, Thanks for your reply.

No BOOT0 pin isn’t connected to anything. The board is in the out-of-the-box state, no changes have been made. JP2 is in STLINK side, JP4(IDD) on and JP5 (3v3) on.

I’ve seen this exact issue when BOOT0 pin is not connected (floating). Jumper it to GND and retry.

I’ve put a jumper between BT0 pin and GND. The debug console output that I’m getting is the following:

PlatformIO: debug_tool = stlink
PlatformIO: Initializing remote target…
xPack OpenOCD x86_64 Open On-Chip Debugger 0.11.0+dev (2021-10-16-21:19)
Licensed under GNU GPL v2
For bug reports, read
OpenOCD: Bug Reporting
srst_only separate srst_nogate srst_open_drain connect_deassert_srst

Info : tcl server disabled
Info : telnet server disabled
Info : STLINK V3J2M1 (API v3) VID:PID 0483:374E
Info : Target voltage: 3.283200
Info : Unable to match requested speed 1800 kHz, using 1000 kHz
Info : Unable to match requested speed 1800 kHz, using 1000 kHz
Info : clock speed 1000 kHz
Info : stlink_dap_op_connect(connect)
Info : SWD DPIDR 0x6ba02477
Warn : target stm32h7x.ap2 examination failed
Warn : target stm32h7x.cpu0 examination failed
Warn : target stm32h7x.cpu1 examination failed
Info : gdb port disabled
Info : starting gdb server for stm32h7x.cpu0 on pipe
Info : starting gdb server for stm32h7x.cpu1 on pipe
Info : accepting ‘gdb’ connection from pipe
Error: Target not examined yet
Error executing event gdb-attach on target stm32h7x.cpu0:

Error: Target not examined yet
Error: auto_probe failed
Error: Connect failed. Consider setting up a gdb-attach event for the target to prepare target for GDB connect, or use ‘gdb_memory_map disable’.
Error: attempted ‘gdb’ connection rejected
Info : accepting ‘gdb’ connection from pipe
Error: Target not examined yet
Error executing event gdb-attach on target stm32h7x.cpu1:

Error: Target not examined yet
Error: auto_probe failed
Error: Connect failed. Consider setting up a gdb-attach event for the target to prepare target for GDB connect, or use ‘gdb_memory_map disable’.
Error: attempted ‘gdb’ connection rejected
Error: error during select: Unknown error
.pioinit:13: Error in sourced command file:
Remote communication error. Target disconnected.: Success.

Does it make a difference when you press and hold the RESET button on the Nucleo board, start the debug session again, and when you see start seeing output of OpenOCD in the debug console, release the reset button?

Also - to rule out a previous upload putting the µC in a tricky state: did the board have a blinking LED when powered up for the first time? Did you upload other firmware to this board which may affect how the µC comes out of reset (i.e. a bad clock config, or disabling the SWD pins).

AFAIU, such tricky states can only be fixed by keeping the µC in reset during the next upload, hence @maxgerhardt 's suggestion to keep the RESET button pressed until the upload actually is taking place.

For me on this board debug not working too. During probes i got your error just because first run debug process not terminated and running in background. So just check processes and kill them all :slight_smile:

Sometime after upload firmware I got strange thing: console worked ok, leds is blinking ok, but can’t connect to board like you. I check connection from STM32CubeProgrammer and got “Target not found”. So I need erase flash sector and reupload firmware.

  1. Turn board off
  2. Put 3V3 to BOOT0
  3. Turn on
  4. Erase sector with f/w from STM32CubeProgrammer
  5. Turn off, remove 3V3 (or put to GND)
  6. Turn on and upload.

Now I try to debug empty firmware on this board with

void main(void) {
    int i = 0;
    while(1) {
        i++;
    }
} 

For this moment without success but with another error.

I tried keeping Reset pressed and then releasing it when the Console debug output stops. This actually starts the onboard debug that suddenly stops with a SIGINT. Here’s the full output.

Info : tcl server disabled

Info : telnet server disabled

Info : STLINK V3J2M1 (API v3) VID:PID 0483:374E

Info : Target voltage: 3.282612

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : clock speed 1000 kHz

Info : stlink_dap_op_connect(connect)

Info : SWD DPIDR 0x6ba02477

Info : stm32h7x.cpu0: Cortex-M7 r1p1 processor detected

Info : stm32h7x.cpu0: target has 8 breakpoints, 4 watchpoints

Info : stm32h7x.cpu0: external reset detected

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Info : stm32h7x.cpu1: external reset detected

Info : gdb port disabled

Info : starting gdb server for stm32h7x.cpu0 on pipe

Info : starting gdb server for stm32h7x.cpu1 on pipe

Info : accepting ‘gdb’ connection from pipe

Error: timed out while waiting for target halted

Error executing event gdb-attach on target stm32h7x.cpu0:

Error: Failed to read memory at 0x5c001000

Error: auto_probe failed

Error: Connect failed. Consider setting up a gdb-attach event for the target to prepare target for GDB connect, or use ‘gdb_memory_map disable’.

Error: attempted ‘gdb’ connection rejected

Info : accepting ‘gdb’ connection from pipe

Info : Halt timed out, wake up GDB.

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (2) size is 1024 kb, base address is 0x08000000

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (3) size is 1024 kb, base address is 0x08100000

Info : New GDB Connection: 1, Target stm32h7x.cpu1, state: halted

Warn : negative acknowledgment, but no packet pending

Warn : negative acknowledgment, but no packet pending

Ignoring packet error, continuing…

warning: unrecognized item “timeout” in “qSupported” response

Warn : negative acknowledgment, but no packet pending

Warn : keep_alive() was not invoked in the 1000 ms timelimit. GDB alive packet not sent! (20023 ms). Workaround: increase “set remotetimeout” in GDB

Error: Failed to read memory at 0x00000002

Error: Failed to read memory at 0xfffff000

0xfffffffe in ?? ()

Loading section rom_start, size 0x298 lma 0x8000000

Loading section text, size 0x32d2 lma 0x8000298

Loading section .ARM.exidx, size 0x8 lma 0x800356c

Loading section initlevel, size 0x98 lma 0x8003574

Loading section devices, size 0x168 lma 0x800360c

Loading section sw_isr_table, size 0x4b0 lma 0x8003774

Loading section device_handles, size 0x78 lma 0x8003c24

Loading section rodata, size 0x318 lma 0x8003c9c

Loading section datas, size 0x30 lma 0x8003fb4

Loading section device_states, size 0x3c lma 0x8003fe4

Start address 0x8001038, load size 16414

Transfer rate: 10 KB/sec, 107 bytes/write.

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x08001038 msp: 0x24000700

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

Temporary breakpoint 1 at 0x80002cc: file src\main.c, line 31.

PlatformIO: Initialization completed

PlatformIO: Resume the execution to debug_init_break = tbreak main

PlatformIO: More configuration options → Redirecting...

Error: stm32h7x.cpu1 – clearing lockup after double fault

stm32h7x.cpu1 – clearing lockup after double fault

Polling target stm32h7x.cpu1 failed, trying to reexamine

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Program

received signal SIGINT, Interrupt.

Error: Failed to read memory at 0x00000002

Error: Failed to read memory at 0xfffff000

0xfffffffe in ?? ()

Error: Failed to read memory at 0xfffffff8

Error: Failed to read memory at 0xfffff000

With holding reset same thing for me. Exactly same output.

That doesn’t look good – does the blinky example on its work when you upload it in regards to blinking the LED? Is uploading to the board still possible after debugging fails?

Hmm … it looks like this board includes the ST-Link v3, not the v2.1 on most other Nucleos.
Perhaps because the H745 is a dual-core chip, with both an M7+ and an M4 CPU?
I do have such a board (that same Nucleo, I think), but don’t have any experience with it.

Yes, the upload is still working, even if I get this output

debug_level: 1

srst_only separate srst_nogate srst_open_drain connect_deassert_srst

Error: stm32h7x.cpu1 – clearing lockup after double fault
Polling target stm32h7x.cpu1 failed, trying to reexamine
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x08001030 msp: 0x24000700
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc
** Programming Started **
Warn : Adding extra erase range, 0x08004020 … 0x0801ffff
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
Error: stm32h7x.cpu1 – clearing lockup after double fault
target halted due to debug-request, current mode: Handler HardFault
xPSR: 0x01000003 pc: 0xfffffffe msp: 0xffffffd8
Polling target stm32h7x.cpu1 failed, trying to reexamine
target halted due to debug-request, current mode: Thread
xPSR: 0x41000000 pc: 0x08000bfe psp: 0x24000870
shutdown command invoked

Yes it has the ST-Link v3 on board.

But does LED blink in accordance to the code?

Yes, the led behavior is the expected one.

Weird how when it halts the MCU then it says that it’s in a double (hard)fault, hm…

You could sanity-check that debugging works when using other frameworks. E.g., use the platform-ststm32/examples/cmsis-blink at develop · platformio/platform-ststm32 · GitHub project with the platformio.ini

[env:nucleo_h745zi_q]
platform = ststm32
board = nucleo_h745zi_q
framework = cmsis
upload_protocol = stlink
debug_tool = stlink
build_flags = -DSTM32H7 -DCORE_CM7
; counteracts a possible linkerscript bug for cmsis framework
board_upload.maximum_ram_size = 131072

I’m not sure what else besides BOOT0 and RESET configuration could hold this back from working – please open an issue in Issues · platformio/platform-ststm32 · GitHub to get help from the developers (and link to this thread) if it still doesn’t work.

Almost same story with CMSIS blinking project. Debug crashes with a SIGINT but upload seems not working. Now LED doesn’t blink anymore. The error message seem very similar btw.

Debug Output

Info : tcl server disabled

Info : telnet server disabled

Info : STLINK V3J2M1 (API v3) VID:PID 0483:374E

Info : Target voltage: 3.284800

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : Unable to match requested speed 1800 kHz, using 1000 kHz

Info : clock speed 1000 kHz

Info : stlink_dap_op_connect(connect)

Info : SWD DPIDR 0x6ba02477

Info : stm32h7x.cpu0: Cortex-M7 r1p1 processor detected

Info : stm32h7x.cpu0: target has 8 breakpoints, 4 watchpoints

Info : stm32h7x.cpu0: external reset detected

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Info : stm32h7x.cpu1: external reset detected

Info : gdb port disabled

Info : starting gdb server for stm32h7x.cpu0 on pipe

Info : starting gdb server for stm32h7x.cpu1 on pipe

Info : accepting ‘gdb’ connection from pipe

Error: timed out while waiting for target halted

Error executing event gdb-attach on target stm32h7x.cpu0:

Error: Failed to read memory at 0x5c001000

Error: auto_probe failed

Error: Connect failed. Consider setting up a gdb-attach event for the target to prepare target for GDB connect, or use ‘gdb_memory_map disable’.

Error: attempted ‘gdb’ connection rejected

Info : accepting ‘gdb’ connection from pipe

Info : Halt timed out, wake up GDB.

Error: stm32h7x.cpu1 – clearing lockup after double fault

target halted due to debug-request, current mode: Handler HardFault

xPSR: 0x01000003 pc: 0xfffffffe msp: 0xffffffd8

Polling target stm32h7x.cpu1 failed, trying to reexamine

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (2) size is 1024 kb, base address is 0x08000000

Info : Device: STM32H74x/75x

Error: Failed to read memory at 0x1ff1e882

Info : STM32H7 flash has dual banks

Info : Bank (3) size is 1024 kb, base address is 0x08100000

Info : New GDB Connection: 1, Target stm32h7x.cpu1, state: halted

Warn : negative acknowledgment, but no packet pending

Warn : negative acknowledgment, but no packet pending

Ignoring packet error, continuing…

warning: unrecognized item “timeout” in “qSupported” response

Warn : negative acknowledgment, but no packet pending

Warn : keep_alive() was not invoked in the 1000 ms timelimit. GDB alive packet not sent! (19017 ms). Workaround: increase “set remotetimeout” in GDB

target halted due to debug-request, current mode: Handler HardFault

xPSR: 0x61000003 pc: 0x08000328 msp: 0x2007ffb8

Error: Failed to read memory at 0x00000002

Error: Failed to read memory at 0xfffff000

0xfffffffe in ?? ()

Loading section .isr_vector, size 0x298 lma 0x8000000

Loading section .text, size 0x1c4 lma 0x8000298

Loading section .init_array, size 0x4 lma 0x800045c

Loading section .fini_array, size 0x4 lma 0x8000460

Start address 0x80002d8, load size 1124

Transfer rate: 7 KB/sec, 86 bytes/write.

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x080002d8 msp: 0x20080000

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0x080002d8 msp: 0x20080000

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

target halted due to debug-request, current mode: Thread

xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc

Temporary breakpoint 1 at 0x80003c4: file src\main.c, line 106.

PlatformIO: Initialization completed

PlatformIO: Resume the execution to debug_init_break = tbreak main

PlatformIO: More configuration options → Redirecting...

Error: stm32h7x.cpu1 – clearing lockup after double fault

stm32h7x.cpu1 – clearing lockup after double fault

Polling target stm32h7x.cpu1 failed, trying to reexamine

Info : stm32h7x.cpu1: Cortex-M4 r0p1 processor detected

Info : stm32h7x.cpu1: target has 6 breakpoints, 4 watchpoints

Program

received signal SIGINT, Interrupt.

Error: Failed to read memory at 0x00000002

Error: Failed to read memory at 0xfffff000

0xfffffffe in ?? ()

Error: Failed to read memory at 0xfffffff8

Error: Failed to read memory at 0xfffff000

Upload

debug_level: 1

srst_only separate srst_nogate srst_open_drain connect_deassert_srst

target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x080002d8 msp: 0x20080000
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc
** Programming Started **
Warn : Adding extra erase range, 0x08000460 … 0x0801ffff
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
Error: stm32h7x.cpu1 – clearing lockup after double fault
target halted due to debug-request, current mode: Handler HardFault
xPSR: 0x01000003 pc: 0xfffffffe msp: 0xffffffd8
Polling target stm32h7x.cpu1 failed, trying to reexamine
target halted due to debug-request, current mode: Handler HardFault
xPSR: 0x61000003 pc: 0x08000328 msp: 0x2007ffb8
shutdown command invoked

Is there a way to factory reset it using STM32CubeProgrammer ? Maybe trying to debug it using platformio caused a memory corruption due to wrong settings.

I have manual check registers with BOOT0=1, and set nothing strange. All write protection is off, PCROP-protection also. Looks all is fine with MCU.

Sorry, may be it not related observation, but a few more ingridients in our soup:

  1. BOOT=1, erase sector at 0x08000000
  2. BOOT=0, cold start, upload firmware, see “clearing lockup after double fault” on both cores. Led is on, not blink.
  3. Push reset button, led is blinking fine.
  4. Try to upload again, see “clearing lockup after double faul” just for cpu1, cpu0 is fine now. Upload ok, led is on, not blinking, so push reset. Led is blinking now.
  5. Flash again, upload ok, same situation.
  6. Turn power off. Then on, so cold start. Led is blinking.
  7. Try to upload firmware again. Now “Target examination failed”. STM32CubeProgrammer: “No STM32 Target found!”
  8. BOOT=1, erase 0 sector. Then power off, Boot=0, upload is ok now.

Thoughts:

  1. Some problems with OpenOCD + ST-Link V3. (I have upload st-link firmware to latest)
  2. Zephyr’s problem, some initialization during boot.
  3. STM32H745 specific problem, like Secure Boot and so on.

About debuging. I erase sector 0, when start debugging session after cold start and with Reset is pressed. Gdb is connected and I see register rc=0xfffffffe (is it ok for hardware failure?), and stack

??@0xfffffffe
<signal handler called>@0xfffffff9
??@0x00000000

After reset led is not blinking. But after upload this firmware after cold start I can connect to board from SMT32CubeProgrammes without any problems. I read memory and what can I see? Just 0xff in 0 sector. So debug firmware not flashed. And for my opinion it is start point.

Sorry for my language and begginer’s thoughts, last my assembler code was on CISC architecture on Intel 8088 :wink:

“Target not found problem” actual only if connection mode in STM32CubeProgrammer is “Hot-plug”. In other modes where is no problems.

After some playing I can start debug session with OpenOCD from console w/o PlatformIO. Can pass continue command and led starts blink. It is before power off.

Further investigation revealed after power reset in DBGMCU register bit D3DBGCKEN, D1DBGCKEN set to 0, so Domain 1 and Domain 3 debug clock is disabled. And related reference D3 power settings reset after power cycle. That why after power off and on I have “no link” and that why hot-plug connection is not working.

I think it is related to can’t start debug session. May be application must initialise D3 power / clock / DBG registers during initialization.

Now my head is off. I will test some initialization tomorrow.


Already post a lot of messages :wink: Just append.

I think I got it!

I have two not related problems, but topic starter just one.

  1. Can’t start debug because can’t upload firmware. The reason is DBGMCU_CR register has 0x00000000 value after reset, and D1 + D3 domain’s debug is disabled. Just proper initialization resolve it.

  2. Can’t start debug like @fisherman6v6 describe. The image flashed but we got hw failure.

We have two cores. On M7 we have uploaded fw and on M4 where is no fw, but core started by default. When PlatformIO starts debug session it starts OpenOCD with pipe mode by default. But we have two cores and OpenOCD put output from both cores in one pipe. So hw failure from M4 core, not from M7. M7 from this moment halted for gdb.

Resolve it simple: just put debug_port = localhost:3333 in env settings in platformio.ini for M7 core and localhost:3334 for M4 core. This disables pipe (debug/process/server.py) and enable tcp server.

Now I starts debug, and see break at main() function. But when press F10/F11 system never break again. But it is another story.