GCC Context Switching for AVR CPUs

Thread context switching for avr-gcc. More...

Collaboration diagram for GCC Context Switching for AVR CPUs:

Data Structures
struct	SWITCHFRAME
	ARM7TDMI GCC context switch frame layout. More...
struct	ENTERFRAME
	Thread entry frame layout. More...
Defines
#define	LONG_PTR_P(lp, mem_p)
Functions
void	NutThreadSwitch (void)
	Switch to another thread.
HANDLE	NutThreadCreate (char *name, void(*fn)(void *), void *arg, size_t stackSize)
	Create a new thread.

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Detailed Description

Thread context switching for avr-gcc.

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Define Documentation

#define LONG_PTR_P	(		lp,
			mem_p
	)

Value:

__asm__ __volatile__("ldi %A0, lo8("#mem_p ")" "\n\t" \
                         "ldi %B0, hi8("#mem_p ")" "\n\t" \
                         "ldi %C0, hh8("#mem_p ")" "\n\t" \
                         "clr %D0" \
                         :"=d" (lp))

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Function Documentation

void NutThreadSwitch

(

void

)

Switch to another thread.

Stop the current thread, saving its context. Then start the one with the highest priority, which is ready to run.

Application programs typically do not call this function.

Note:

CPU interrupts must be disabled before calling this function.

HANDLE NutThreadCreate	(	char *	name,
		void(*)(void *)	fn,
		void *	arg,
		size_t	stackSize
	)

Create a new thread.

If the current thread's priority is lower or equal than the default priority (64), then the current thread is stopped and the new one is started.

Parameters:

name	String containing the symbolic name of the new thread, up to 8 characters long.
fn	The thread's entry point, typically created by the THREAD macro.
arg	Argument pointer passed to the new thread.
stackSize	Number of bytes of the stack space allocated for the new thread.

Note:

On ARM some targets the thread must run in ARM mode. Thumb mode is not supported.

Returns:

Pointer to the NUTTHREADINFO structure or NULL to indicate an error.

References __os_trf, __os_trs, ENTERFRAME::cef_arghi, ENTERFRAME::cef_arglo, ENTERFRAME::cef_pchi, ENTERFRAME::cef_pclo, ENTERFRAME::cef_r1, ENTERFRAME::cef_rampz, ENTERFRAME::cef_sreg, SWITCHFRAME::csf_pchi, SWITCHFRAME::csf_pclo, DEADBEEF, fprintf(), memcpy(), NutDumpThreadList(), NutEnterCritical, NutExitCritical, NutStackAlloc, NutThreadAddPriQueue(), nutThreadList, NutThreadSwitch(), runningThread, runQueue, _NUTTHREADINFO::td_memory, _NUTTHREADINFO::td_name, _NUTTHREADINFO::td_next, _NUTTHREADINFO::td_priority, _NUTTHREADINFO::td_queue, _NUTTHREADINFO::td_sp, _NUTTHREADINFO::td_state, _NUTTHREADINFO::td_timer, and TDS_READY.

Here is the call graph for this function: