微處理器 - STMicroelectronics STM32F103 - Assembly - LED

參考資料：
https://www.st.com/resource/en/reference_manual/cd00171190-stm32f101xx-stm32f102xx-stm32f103xx-stm32f105xx-and-stm32f107xx-advanced-arm-based-32-bit-mcus-stmicroelectronics.pdf

RCC_APB2ENR暫存器，需要開啟GPIO-C的Clock


LED位置是PC13，設定成Output 50MHz


輸出資料


main.s

    .thumb
    .cpu cortex-m3
    .syntax unified

    .equ GPIOC_CRL,   0x40011000
    .equ GPIOC_CRH,   0x40011004
    .equ GPIOC_IDR,   0x40011008
    .equ GPIOC_ODR,   0x4001100c
    .equ GPIOC_BSRR,  0x40011010
    .equ GPIOC_BRR,   0x40011014
    .equ GPIOC_LCKR,  0x40011018
    .equ RCC_APB2ENR, 0x40021018

    .equ STACKINIT,   0x20005000

    .global _start
    .section .text
    .org 0x0
    .word STACKINIT
    .word _start

    .org 0x100
    .align 2
    .thumb_func
_start:
    ldr r0, =0x00000010
    ldr r1, =RCC_APB2ENR
    str r0, [r1]

    ldr r0, =GPIOC_CRH
    ldr r1, =(3 << 20)
    str r1, [r0]

    ldr r2, =GPIOC_ODR
    ldr r3, =(1 << 13)
loop:
    str r3, [r2]
    eor r3, (1 << 13)
    ldr r0, =50
    bl delay
    b loop
 
    .align 2
    .thumb_func
delay:
    push {lr}
0:
    ldr r1, =8000
1:
    sub r1, #1
    cmp r1, #0
    bne 1b
    sub r0, #1
    cmp r0, #0
    bne 0b
    pop {pc} 
    .end

main.ld

MEMORY {
    RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 20K
    FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 128K
}
 
SECTIONS {
    .text : { 
        *(.text)
    } > FLASH
   
    .bss : { 
        *(.bss)
    } > RAM
 
    .data : { 
        *(.data)
    } > RAM
}

Makefile

all:
	arm-none-eabi-as -ggdb -mcpu=cortex-m3 -mthumb -mthumb-interwork -o main.o main.s
	arm-none-eabi-ld -T main.ld -o main.elf main.o
	arm-none-eabi-objcopy -O binary main.elf main.bin
 
flash:
	sudo openocd -f /usr/local/share/openocd/scripts/interface/stlink.cfg -f /usr/local/share/openocd/scripts/target/stm32f1x.cfg -c "program main.bin reset exit 0x8000000"
 
debug:
	sudo openocd -f /usr/local/share/openocd/scripts/interface/stlink-v2.cfg -f /usr/local/share/openocd/scripts/target/stm32f1x.cfg -c "program main.bin halt 0x8000000"
 
clean:
	rm -rf main.o main.elf main.bin

編譯

$ make
    arm-none-eabi-as -ggdb -mcpu=cortex-m3 -mthumb -mthumb-interwork -o main.o main.s
    arm-none-eabi-ld -T main.ld -o main.elf main.o
    arm-none-eabi-objcopy -O binary main.elf main.bin

燒錄

$ make flash
    sudo openocd -f /usr/local/share/openocd/scripts/interface/stlink.cfg -f /usr/local/share/openocd/scripts/target/stm32f1x.cfg -c "program main.bin reset exit 0x8000000"
    Open On-Chip Debugger 0.11.0-rc1+dev-00010-gc69b4deae-dirty (2020-12-27-01:20)
    Licensed under GNU GPL v2
    For bug reports, read
    http://openocd.org/doc/doxygen/bugs.html
    Info : auto-selecting first available session transport "hla_swd". To override use 'transport select '.
    Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
    Info : clock speed 1000 kHz
    Info : STLINK V2J17S4 (API v2) VID:PID 0483:3748
    Info : Target voltage: 3.195294
    Info : stm32f1x.cpu: hardware has 6 breakpoints, 4 watchpoints
    Info : starting gdb server for stm32f1x.cpu on 3333
    Info : Listening on port 3333 for gdb connections
    target halted due to debug-request, current mode: Thread
    xPSR: 0x01000000 pc: 0x08000100 msp: 0x20005000
    ** Programming Started **
    Info : device id = 0x20036410
    Info : flash size = 128kbytes
    ** Programming Finished **
    ** Resetting Target **
    shutdown command invoked

完成