STM32F103C8T6 (6.1 Derinimas (angl. debugging) Visual Studio Code aplinkoje)

1. VSCode sudiegiame Native debug extension'ą
2. Papildome platformio.ini

[env:bluepill_f103c8]
platform = ststm32
board = bluepill_f103c8
framework = cmsis
build_flags = -g

3. Atidarome Debug panelę (CTRL+SHIFT+D), pasirenkame Add Configuration->GDB ir launch.json papildome

{
	"name": "GDB",
	"type": "gdb",
	"request": "launch",
	"cwd": "${workspaceRoot}",
	"target": "C:/Users/username/Documents/PlatformIO/Projects/BluePill01/.pioenvs/bluepill_f103c8/firmware.elf",
	"gdbpath" : "C:/Users/username/.platformio/packages/toolchain-gccarmnoneeabi/bin/arm-none-eabi-gdb.exe",
	"autorun": [
                "target remote localhost:3333",
                "monitor arm semihosting enable", // Ši eilutė reikalinga siųsti duomenis į gdb terminalą
                "monitor reset halt",
                "symbol-file C:/Users/win7/Documents/PlatformIO/Projects/BluePill02_ILI9341/.pioenvs/bluepill_f103c8/firmware.elf"
                ]
}

4. Spaudžiame New Terminal ir paleidžiame OpenOCD:

C:\Users\username\.platformio\packages\tool-openocd\bin>openocd.exe -f ../scripts/interface/stlink.cfg -f ../scripts/target/stm32f1x.cfg

Jei rodo klaidos pranešimą:

Error: init mode failed (unable to connect to the target)
in procedure 'init'
in procedure 'ocd_bouncer'

ir RESET nepadeda tai reikia atjungti BluePill ir vel prijungti prie STLinkV2

5. Spaudžiam Start Debugging ir pasirenkam GDB

Kaip peržiūrėti atmintyje esančius duomenis?

Debug'inant einame į "DEBUG CONSOLE" langą ir po juo kur yra ">" rašome: "x/8xw 0x08000000"

• x - komanda
• 8 - kiek duomenų rodyti
• x - formatas (hexadecimal)
• w - tipas (word (keturi baitai))

https://sourceware.org/gdb/onlinedocs/gdb/Memory.html

Pvz.: (pažiūrėti GPIOA reikšmes, adresas iš "STM32F Reference Manual.pdf" 50 ir 193 psl.):

x/4xw 0x40010800
0x40010800:	0x44444444	0x88844444	0x0000dff9	0x00000000

• Atminties adresas - 0x40010800
• GPIOA_CRL reikšmė - 0x44444444
• GPIOA_CRH reikšmė - 0x88844444
• GPIOA_IDR reikšmė - 0x0000dff9
• GPIOA_ODR reikšmė - 0x00000000

Kaip siųsti duomenis į gdb terminalą?

void send_command(int command, void *message)
{
   asm("mov r0, %[cmd];"
       "mov r1, %[msg];"
       "bkpt #0xAB"
         :
         : [cmd] "r" (command), [msg] "r" (message)
         : "r0", "r1", "memory");
}

void put_char(char c)
{
    asm (
    "mov r0, #0x03\n"   /* SYS_WRITEC */
    "mov r1, %[msg]\n"
    "bkpt #0xAB\n"
    :
    : [msg] "r" (&c)
    : "r0", "r1"
    );
}

int main(void)
{
    // Some code
    for (;;)
    {
        const char s[] = "Hello world\n";
        uint32_t m[] = { 2/*stderr*/, (uint32_t)s, sizeof(s)/sizeof(char) - 1 };
        send_command(0x05/* some interrupt ID */, m);

        put_char('H');
        put_char('e');
        put_char('l');
        put_char('l');
        put_char('o');
    }
}

http://sushihangover.github.io/arm-cortex-m-semihosting-with-qemu/
https://electronics.stackexchange.com/questions/149387/how-do-i-print-debug-messages-to-gdb-console-with-stm32-discovery-board-using-gd