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#ifndef CONTEXT_H
#define CONTEXT_H
#include <avr/interrupt.h>
/*
* The macros SAVE_CONTEXT(), RESTORE_CONTEXT() as well as the code contained in
* init_stack is adapted from the FreeRTOS kernel (http://www.freertos.org/).
* Here by copyright, credits attributed to wherever they belong.
*/
#define SAVE_CONTEXT() \
asm volatile ( \
"push r0 \n\t" \
"in r0, __SREG__ \n\t" \
"push r0 \n\t" \
"push r1 \n\t" \
"clr r1 \n\t" \
"push r2 \n\t" \
"push r3 \n\t" \
"push r4 \n\t" \
"push r5 \n\t" \
"push r6 \n\t" \
"push r7 \n\t" \
"push r8 \n\t" \
"push r9 \n\t" \
"push r10 \n\t" \
"push r11 \n\t" \
"push r12 \n\t" \
"push r13 \n\t" \
"push r14 \n\t" \
"push r15 \n\t" \
"push r16 \n\t" \
"push r17 \n\t" \
"push r18 \n\t" \
"push r19 \n\t" \
"push r20 \n\t" \
"push r21 \n\t" \
"push r22 \n\t" \
"push r23 \n\t" \
"push r24 \n\t" \
"push r25 \n\t" \
"push r26 \n\t" \
"push r27 \n\t" \
"push r28 \n\t" \
"push r29 \n\t" \
"push r30 \n\t" \
"push r31 \n\t" \
"lds r26, current \n\t" \
"lds r27, current +1 \n\t" \
"in r0, __SP_L__ \n\t" \
"st x+, r0 \n\t" \
"in r0, __SP_H__ \n\t" \
"st x+, r0 \n\t" \
"lds r26, kstack \n\t" \
"lds r27, kstack + 1 \n\t" \
"ld r28, x+ \n\t" \
"out __SP_L__, r28 \n\t" \
"ld r29, x+ \n\t" \
"out __SP_H__, r29 \n\t" \
)
#define RESTORE_CONTEXT() \
asm volatile ( \
"lds r26, kstack \n\t" \
"lds r27, kstack +1 \n\t" \
"in r0, __SP_L__ \n\t" \
"st x+, r0 \n\t" \
"in r0, __SP_H__ \n\t" \
"st x+, r0 \n\t" \
"lds r26, current \n\t" \
"lds r27, current + 1 \n\t" \
"ld r28, x+ \n\t" \
"out __SP_L__, r28 \n\t" \
"ld r29, x+ \n\t" \
"out __SP_H__, r29 \n\t" \
"pop r31 \n\t" \
"pop r30 \n\t" \
"pop r29 \n\t" \
"pop r28 \n\t" \
"pop r27 \n\t" \
"pop r26 \n\t" \
"pop r25 \n\t" \
"pop r24 \n\t" \
"pop r23 \n\t" \
"pop r22 \n\t" \
"pop r21 \n\t" \
"pop r20 \n\t" \
"pop r19 \n\t" \
"pop r18 \n\t" \
"pop r17 \n\t" \
"pop r16 \n\t" \
"pop r15 \n\t" \
"pop r14 \n\t" \
"pop r13 \n\t" \
"pop r12 \n\t" \
"pop r11 \n\t" \
"pop r10 \n\t" \
"pop r9 \n\t" \
"pop r8 \n\t" \
"pop r7 \n\t" \
"pop r6 \n\t" \
"pop r5 \n\t" \
"pop r4 \n\t" \
"pop r3 \n\t" \
"pop r2 \n\t" \
"pop r1 \n\t" \
"pop r0 \n\t" \
"out __SREG__, r0 \n\t" \
"pop r0 \n\t" \
)
char* init_stack(const char* const mem_low, const char* const mem_high, void (*entry)(char), char args);
static inline void init_kstack(char **kstack) {
*kstack = (char*) SP;
}
#define RETURN() asm volatile("ret");
#endif
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