in portable/GCC/ATMega323/port.c [83:298]
asm volatile ( "push r0 \n\t" \
"in r0, __SREG__ \n\t" \
"cli \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, pxCurrentTCB \n\t" \
"lds r27, pxCurrentTCB + 1 \n\t" \
"in r0, 0x3d \n\t" \
"st x+, r0 \n\t" \
"in r0, 0x3e \n\t" \
"st x+, r0 \n\t" \
);
/*
* Opposite to portSAVE_CONTEXT(). Interrupts will have been disabled during
* the context save so we can write to the stack pointer.
*/
#define portRESTORE_CONTEXT() \
asm volatile ( "lds r26, pxCurrentTCB \n\t" \
"lds r27, pxCurrentTCB + 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" \
);
/*-----------------------------------------------------------*/
/*
* Perform hardware setup to enable ticks from timer 1, compare match A.
*/
static void prvSetupTimerInterrupt( void );
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
{
uint16_t usAddress;
/* Place a few bytes of known values on the bottom of the stack.
This is just useful for debugging. */
*pxTopOfStack = 0x11;
pxTopOfStack--;
*pxTopOfStack = 0x22;
pxTopOfStack--;
*pxTopOfStack = 0x33;
pxTopOfStack--;
/* Simulate how the stack would look after a call to vPortYield() generated by
the compiler. */
/*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */
/* The start of the task code will be popped off the stack last, so place
it on first. */
usAddress = ( uint16_t ) pxCode;
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
pxTopOfStack--;
usAddress >>= 8;
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
pxTopOfStack--;
/* Next simulate the stack as if after a call to portSAVE_CONTEXT().
portSAVE_CONTEXT places the flags on the stack immediately after r0
to ensure the interrupts get disabled as soon as possible, and so ensuring
the stack use is minimal should a context switch interrupt occur. */
*pxTopOfStack = ( StackType_t ) 0x00; /* R0 */
pxTopOfStack--;
*pxTopOfStack = portFLAGS_INT_ENABLED;
pxTopOfStack--;
/* Now the remaining registers. The compiler expects R1 to be 0. */
*pxTopOfStack = ( StackType_t ) 0x00; /* R1 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x02; /* R2 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x03; /* R3 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x04; /* R4 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x05; /* R5 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x06; /* R6 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x07; /* R7 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x08; /* R8 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x09; /* R9 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x10; /* R10 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x11; /* R11 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x12; /* R12 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x13; /* R13 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x14; /* R14 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x15; /* R15 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x16; /* R16 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x17; /* R17 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x18; /* R18 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x19; /* R19 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x20; /* R20 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x21; /* R21 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x22; /* R22 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x23; /* R23 */
pxTopOfStack--;
/* Place the parameter on the stack in the expected location. */
usAddress = ( uint16_t ) pvParameters;
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
pxTopOfStack--;
usAddress >>= 8;
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x26; /* R26 X */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x27; /* R27 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x28; /* R28 Y */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x29; /* R29 */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x30; /* R30 Z */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x031; /* R31 */
pxTopOfStack--;
/*lint +e950 +e611 +e923 */
return pxTopOfStack;
}