概 述 #if defined ( __CC_ARM ) #define __ASM __asm /*!< asm keyword for ARM Compiler */ #define __INLINE __inline /*!< inline keyword for ARM Compiler */ #define __STATIC_INLINE static __inline
#elif defined ( __GNUC__ ) #define __ASM __asm /*!< asm keyword for GNU Compiler */ #define __INLINE inline /*!< inline keyword for GNU Compiler */ #define __STATIC_INLINE static inline
#elif defined ( __ICCARM__ ) #define __ASM __asm /*!< asm keyword for IAR Compiler */ #define __INLINE inline /*!< inline keyword for IAR Compiler. Only available in High optimization mode! */ #define __STATIC_INLINE static inline
#elif defined ( __TMS470__ ) #define __ASM __asm /*!< asm keyword for TI CCS Compiler */ #define __STATIC_INLINE static inline
#elif defined ( __TASKING__ ) #define __ASM __asm /*!< asm keyword for TASKING Compiler */ #define __INLINE inline /*!< inline keyword for TASKING Compiler */ #define __STATIC_INLINE static inline
#elif defined ( __CSMC__ ) #define __packed #define __ASM _asm /*!< asm keyword for COSMIC Compiler */ #define __INLINE inline /*use -pc99 on compile line !< inline keyword for COSMIC Compiler */ #define __STATIC_INLINE static inline #endif 如果你写过Keil C51,你还会发现有如下(通过预处理)嵌套汇编:
所以,你会发现,不同的编译器,汇编代码还是有差异。当然,这里主要是说C中嵌套汇编与编译器有关。 C中嵌套汇编代码 __ASM uint32_t __get_PSP(void) { mrs r0, psp bx lr }
举 例 static portFORCE_INLINE void vPortRaiseBASEPRI( void ) { uint32_t ulNewBASEPRI = configMAX_SYSCALL_INTERRUPT_PRIORITY;
__asm { /* Set BASEPRI to the max syscall priority to effect a critical section. */ msr basepri, ulNewBASEPRI dsb isb } } 2、FreeRTOS中port.c文件下源代码:
这是之前分享过的一篇文章《一文弄懂STM32复位来源,以及系统与内核复位的区别》中的代码: __asm void NVIC_CoreReset_a(void) { LDR R0, =0xE000ED0C LDR R1, =0x05FA0001 STR R1, [R0] deadloop_Core B deadloop_Core } |
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