system.h

来自「ADS下的bios工程」· C头文件 代码 · 共 44 行

#ifndef  _BIOS_SYSTEM_H
#define  _BIOS_SYSTEM_H


#define sti()								\
	do {								\
		unsigned int dummy;					\
		__asm__ __volatile__(					\
			"mrs	%0, cpsr\n\t"				\
			"orr	%0, %0, #1 << 7\n\t"			\
			"msr	cpsr, %0" : "=r" (dummy) : : "memory");	\
	} while(0)

#define cli()								\
	do {								\
		unsigned int dummy;					\
		__asm__ __volatile__(					\
			"mrs	%0, cpsr\n\t"				\
			"bic	%0, %0, #1 << 7\n\t"			\
			"msr	cpsr_c, %0" : "=r" (dummy) : : "memory");	\
	} while(0)


#define save_flags(x)							\
	({  __asm__ __volatile__(					\
			"mrs	%0, cpsr\n\t" : "=r" (x));		\
	})

#define restore_flags(x)						\
	do {								\
		unsigned int dummy;					\
		__asm__ __volatile__(					\
			"mrs	%0, cpsr\n\t"				\
			"bic	%0, %0, #1 << 7\n\t"			\
			"and	%1, %1, #1 << 7\n\t"			\
			"orr	%0, %0, %1\n\t"				\
			"msr	cpsr, %0" : "=r" (dummy) : "r" (x) : "memory");\
	} while (0)

typedef unsigned long flags_t;


#endif  /* End of _BIOS_SYSTEM_H */