I am new ,in STM32 . I have an old board STM32 value discovery (STM32f100RBT6B) I wrote a code for LED ON But not working ,whats the wrong

#include <stdint.h>

#define RCC_CFGR_BASE_ADDR   0x40012800UL

#define RCC_CFGR_REG_OFFSET   0x04UL

#define RCC_CFGR_REG_ADDR   (RCC_CFGR_BASE_ADDR + RCC_CFGR_REG_OFFSET )

#define RCC_APB2ENR_REG_OFFSET 0x18UL

#define RCC_APB2ENR_REG_ADDR  (RCC_CFGR_BASE_ADDR + RCC_APB2ENR_REG_OFFSET )

#define GPIO_MODE_BASE_ADDR   0x40011000UL

#define GPIO_MODE_REG_OFFSET  0x04UL

#define GPIO_MODE_REG_ADDR   (GPIO_MODE_BASE_ADDR + GPIO_MODE_REG_OFFSET )

#define GPIO_MODE_ODR_OFFSET  0x0CUL

#define GPIO_MODE_ODR_ADDR   (GPIO_MODE_BASE_ADDR + GPIO_MODE_ODR_OFFSET )

int main(void)

{

uint32_t *pRccCfrReg = (uint32_t*)RCC_CFGR_REG_ADDR;

uint32_t *pRccApb2EnReg = (uint32_t*)RCC_APB2ENR_REG_ADDR ;

uint32_t *pGPIOModeReg = (uint32_t*)GPIO_MODE_REG_ADDR;

uint32_t *pGPIO_OdrReg = (uint32_t*)GPIO_MODE_ODR_ADDR;

*pRccCfrReg    |= (0x5 << 23); // Selected HSI as clock bit position 24(1),25(0),26(1)

   *pRccApb2EnReg   = (0x1);// Pheriperal clock enable

*pGPIOModeReg   = (0x22);// // Output mode, max speed 2 MHz. & 00: General purpose output push-pull

while(1)

   {

    *pGPIO_OdrReg = (0xfffff); //

    // for(volatile uint32_t i =0; i<1000; i++)

    // ;

   // *pGPIO_OdrReg = (0x0);

   }

}