tn_arch.h File Reference

Detailed Description

Architecture-dependent routines declaration.

Definition in file tn_arch.h.

Go to the source code of this file.

Functions
void	tn_arch_int_dis (void)
	Unconditionally disable interrupts.
void	tn_arch_int_en (void)
	Unconditionally enable interrupts.
unsigned int	tn_arch_sr_save_int_dis (void)
	Disable interrupts and return previous value of status register, atomically. More...
void	tn_arch_sr_restore (unsigned int sr)
	Restore previously saved status register. More...
TN_UWord *	_tn_arch_stack_start_get (TN_UWord *stack_low_address, int stack_size)
	Should return start stack address, which may be either the lowest address of the stack array or the highest one, depending on the architecture. More...
unsigned int *	_tn_arch_stack_init (TN_TaskBody *task_func, TN_UWord *stack_start, void *param)
	Should initialize stack for new task and return current stack pointer. More...
int	_tn_arch_inside_isr (void)
	Should return 1 if ISR is currently running, 0 otherwise.
void	_tn_arch_context_switch (void)
	Called whenever we need to switch context to other task. More...
void	_tn_arch_context_switch_exit (void)
	Called when some task calls tn_task_exit(). More...
void	_tn_arch_system_start (void)
	Should perform first context switch (to the task pointed to by tn_next_task_to_run). More...

Function Documentation

unsigned int tn_arch_sr_save_int_dis

(

void

)

Disable interrupts and return previous value of status register, atomically.

See also

tn_arch_sr_restore()

void tn_arch_sr_restore

(

unsigned int

sr

)

Restore previously saved status register.

Parameters

sr	status register value previously from tn_arch_sr_save_int_dis()

See also

tn_arch_sr_save_int_dis()

TN_UWord* _tn_arch_stack_start_get	(	TN_UWord *	stack_low_address,
		int	stack_size
	)

Should return start stack address, which may be either the lowest address of the stack array or the highest one, depending on the architecture.

Parameters

stack_low_address	start address of the stack array.
stack_size	size of the stack in int-s, not in bytes.

unsigned int* _tn_arch_stack_init	(	TN_TaskBody *	task_func,
		TN_UWord *	stack_start,
		void *	param
	)

Should initialize stack for new task and return current stack pointer.

Parameters

task_func	Pointer to task body function.
stack_start	Start address of the stack, returned by _tn_arch_stack_start_get().
param	User-provided parameter for task body function.

Returns

current stack pointer (top of the stack)

void _tn_arch_context_switch

(

void

)

Called whenever we need to switch context to other task.

Preconditions:

• interrupts are enabled;
• tn_curr_run_task points to currently running (preempted) task;
• tn_next_task_to_run points to new task to run.

Actions to perform:

• save context of the preempted task to its stack;
• set tn_curr_run_task to tn_next_task_to_run;
• switch context to it.

See also

tn_curr_run_task

tn_next_task_to_run

void _tn_arch_context_switch_exit

(

void

)

Called when some task calls tn_task_exit().

Preconditions:

• interrupts are disabled;
• tn_next_task_to_run is already set to other task.

Actions to perform:

• set tn_curr_run_task to tn_next_task_to_run;
• switch context to it.

See also

tn_curr_run_task

tn_next_task_to_run

void _tn_arch_system_start

(

void

)

Should perform first context switch (to the task pointed to by tn_next_task_to_run).

Preconditions:

• no interrupts are set up yet, so, it's like interrupts disabled
• tn_next_task_to_run is already set to idle task.

Actions to perform:

• set TN_STATE_FLAG__SYS_RUNNING flag in the tn_sys_state variable;
• set tn_curr_run_task to tn_next_task_to_run;
• switch context to it.

See also

TN_STATE_FLAG__SYS_RUNNING

tn_sys_state

tn_curr_run_task

tn_next_task_to_run