Arduino compatible headers

                PB8  D15 I2C? SCL
                PB9  D14 I2C? SDA
                     AVDD
NC  PD1              GND
IOREF       LD4 PA5  D13 SPI? SCK
RESET           PA6  D12 SPI? MISO
3V3             PA7  D11 SPI? MOSI
5V              PB0  D10 SPI? CS
GND             PC7  D9
GND             PA9  D8
VIN    B1 PC13
                PA8  D7
                PB14 D6
AD0 PA0         PB4  D5
AD1 PA1         PB5  D4
AD2 PA4         PB3  D3
AD3 PB1         PA10 D2
AD4 PB11/PB9    PC4  D1  USART1/3 TX
AD5 PB12/PB8    PC5  D0  USART1/3 RX

PA2 USART2_TX ST-LINK
PA3 USART2_TX ST-LINK

openocd -f "interface/stlink.cfg" -c "transport select hla_swd" -f "target/stm32g0x.cfg"
Open On-Chip Debugger 0.12.0-rc2+dev-00028-g9501b263e (2022-12-15-23:13)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
hla_swd
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 2000 kHz
Info : STLINK V2J37M27 (API v2) VID:PID 0483:374B
Info : Target voltage: 3.249836
Info : [stm32g0x.cpu] Cortex-M0+ r0p1 processor detected
Info : [stm32g0x.cpu] target has 4 breakpoints, 2 watchpoints
Info : starting gdb server for stm32g0x.cpu on 3333
Info : Listening on port 3333 for gdb connections
Info : accepting 'gdb' connection on tcp/3333
[stm32g0x.cpu] halted due to debug-request, current mode: Thread
xPSR: 0x81000000 pc: 0x080016ca msp: 0x200005a0
Info : device idcode = 0x10006467 (STM32G0B/G0Cx - Rev A : 0x1000)
Info : RDP level 0 (0xAA)
Info : flash size = 512 KiB
Info : flash mode : dual-bank
Info : device idcode = 0x10006467 (STM32G0B/G0Cx - Rev A : 0x1000)
Info : RDP level 0 (0xAA)
Info : OTP size is 1024 bytes, base address is 0x1fff7000

gdb-multiarch
(gdb) set arch arm
The target architecture is assumed to be arm
(gdb) target extended-remote localhost:3333
Remote debugging using localhost:3333
warning: No executable has been specified and target does not support
determining executable automatically.  Try using the "file" command.
0x080016ca in ?? ()
(gdb) info reg
r0             0x101337            1053495
r1             0x20                32
r2             0x0                 0
r3             0x0                 0
r4             0x32                50
r5             0x101328            1053480
r6             0x33                51
r7             0x3                 3
r8             0xffffffff          -1
r9             0xffffffff          -1
r10            0xffffffff          -1
r11            0xffffffff          -1
r12            0xf                 15
sp             0x200005a0          0x200005a0
lr             0x80016cb           134223563
pc             0x80016ca           0x80016ca
xPSR           0x81000000          -2130706432
msp            0x200005a0          0x200005a0
psp            0xfffffffc          0xfffffffc
primask        0x0                 0
basepri        0x0                 0
faultmask      0x0                 0
control        0x0                 0
(gdb)

https://www.st.com/resource/en/user_manual/um2324-stm32-nucleo64-boards-mb1360-stmicroelectronics.pdf