/**
******************************************************************************
* @file CortexM3/Mode_Privilege/main.c
* @author MCD Application Team
* @version V3.5.0
* @date 08-April-2011
* @brief Main program body.
******************************************************************************
* @attention
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
*
© COPYRIGHT 2011 STMicroelectronics
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"
/** @addtogroup STM32F10x_StdPeriph_Examples
* @{
*/
/** @addtogroup CortexM3_Mode_Privilege
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define SP_PROCESS_SIZE 0x200 /* Process stack size */
#define SP_PROCESS 0x02 /* Process stack */
#define SP_MAIN 0x00 /* Main stack */
#define THREAD_MODE_PRIVILEGED 0x00 /* Thread mode has privileged access */
#define THREAD_MODE_UNPRIVILEGED 0x01 /* Thread mode has unprivileged access */
/* Private macro -------------------------------------------------------------*/
#if defined ( __CC_ARM )
__ASM void __SVC(void)
{
SVC 0x01
BX R14
}
#elif defined ( __ICCARM__ )
static __INLINE void __SVC() { __ASM ("svc 0x01");}
#elif defined ( __GNUC__ )
static __INLINE void __SVC() { __ASM volatile ("svc 0x01");}
#endif
/* Private variables ---------------------------------------------------------*/
__IO uint8_t PSPMemAlloc[SP_PROCESS_SIZE];
__IO uint32_t Index = 0, PSPValue = 0, CurrentStack = 0, ThreadMode = 0;
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
/* Switch Thread mode Stack from Main to Process -----------------------------*/
/* Initialize memory reserved for Process Stack */
for(Index = 0; Index < SP_PROCESS_SIZE; Index++)
{
PSPMemAlloc[Index] = 0x00;
}
/* Set Process stack value */
__set_PSP((uint32_t)PSPMemAlloc + SP_PROCESS_SIZE);
/* Select Process Stack as Thread mode Stack */
__set_CONTROL(SP_PROCESS);
/* Get the Thread mode stack used */
if((__get_CONTROL() & 0x02) == SP_MAIN)
{
/* Main stack is used as the current stack */
CurrentStack = SP_MAIN;
}
else
{
/* Process stack is used as the current stack */
CurrentStack = SP_PROCESS;
/* Get process stack pointer value */
PSPValue = __get_PSP();
}
/* Switch Thread mode from privileged to unprivileged ------------------------*/
/* Thread mode has unprivileged access */
__set_CONTROL(THREAD_MODE_UNPRIVILEGED | SP_PROCESS);
/* Unprivileged access mainly affect ability to:
- Use or not use certain instructions such as MSR fields
- Access System Control Space (SCS) registers such as NVIC and SysTick */
/* Check Thread mode privilege status */
if((__get_CONTROL() & 0x01) == THREAD_MODE_PRIVILEGED)
{
/* Thread mode has privileged access */
ThreadMode = THREAD_MODE_PRIVILEGED;
}
else
{
/* Thread mode has unprivileged access*/
ThreadMode = THREAD_MODE_UNPRIVILEGED;
}
/* Switch back Thread mode from unprivileged to privileged -------------------*/
/* Try to switch back Thread mode to privileged (Not possible, this can be
done only in Handler mode) */
__set_CONTROL(THREAD_MODE_PRIVILEGED | SP_PROCESS);
/* Generate a system call exception, and in the ISR switch back Thread mode
to privileged */
__SVC();
/* Check Thread mode privilege status */
if((__get_CONTROL() & 0x01) == THREAD_MODE_PRIVILEGED)
{
/* Thread mode has privileged access */
ThreadMode = THREAD_MODE_PRIVILEGED;
}
else
{
/* Thread mode has unprivileged access*/
ThreadMode = THREAD_MODE_UNPRIVILEGED;
}
while (1)
{
}
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/