AnttiNykanen

#include "stm32f10x.h"
#include "stm32f10x_conf.h"

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    
    uint16_t rxbuf[64];
    int rxbuf_pos = 0;

iwalpola

STM32duino GPIO Registers and programming

Sources:

http://embedded-lab.com/blog/stm32-gpio-ports-insights/
http://hertaville.com/stm32f0-gpio-tutorial-part-1.html

The libmaple libraries, on which STM32duino is based, provides access to registers by the syntax:

GPIOA->regs->REG