AVR core

Classes
struct	port_extctx
	Interrupt saved context. More...
struct	port_intctx
	System saved context. More...

Macros
#define	NIL_WORKING_AREA(s, n)   stkalign_t s[THD_WA_SIZE(n) / sizeof(stkalign_t)]
	Static working area allocation. More...
#define	port_disable()   asm volatile ("cli" : : : "memory")
	Disables all the interrupt sources.
#define	port_enable()   asm volatile ("sei" : : : "memory")
	Enables all the interrupt sources.
#define	port_init()
	Port-related initialization code. More...
#define	PORT_INT_REQUIRED_STACK   32
	Per-thread stack overhead for interrupts servicing. More...
#define	PORT_IRQ_EPILOGUE()
	IRQ epilogue code. More...
#define	PORT_IRQ_HANDLER(id)   ISR(id)
	IRQ handler function declaration. More...
#define	PORT_IRQ_PROLOGUE()
	IRQ prologue code. More...
#define	port_lock()   asm volatile ("cli" : : : "memory")
	Kernel-lock action. More...
#define	port_lock_from_isr()
	Kernel-lock action from an interrupt handler. More...
#define	port_suspend()   asm volatile ("cli" : : : "memory")
	Disables the interrupt sources below kernel-level priority.
#define	port_switch(ntp, otp)   _port_switch(ntp, otp)
	Performs a context switch between two threads. More...
#define	PORT_THREAD(tname, arg)   __attribute__((noreturn)) void tname(void *arg)
	Thread declaration macro optimized for GCC.
#define	port_unlock()   asm volatile ("sei" : : : "memory")
	Kernel-unlock action. More...
#define	port_unlock_from_isr()
	Kernel-unlock action from an interrupt handler. More...
#define	port_wait_for_interrupt()   asm volatile ("sleep" : : : "memory")
	Enters an architecture-dependent IRQ-waiting mode. More...
#define	SETUP_CONTEXT(tp, workspace, wsize, pf, arg)
	Platform dependent context creation for new threads. More...
#define	STACK_ALIGN(n)   ((((n) - 1) | (sizeof(stkalign_t) - 1)) + 1)
	Enforces a correct alignment for a stack area size value.
#define	THD_WA_SIZE(n)
	Computes the thread working area global size.

Typedefs
typedef uint8_t	stkalign_t
	Stack and memory alignment enforcement.

Functions
void	_port_switch (thread_t *ntp, thread_t *otp)
	Performs a context switch between two threads. More...
void	_port_thread_start (void)
	Start a thread by invoking its work function. More...
void	boardInit (void)
	NIL_IRQ_HANDLER (TIMER0_COMPA_vect)
void	port_halt (void)
	Halts the system. More...

Detailed Description

Macro Definition Documentation

#define NIL_WORKING_AREA	(		s,
			n
	)		stkalign_t s[THD_WA_SIZE(n) / sizeof(stkalign_t)]

Static working area allocation.

This macro is used to allocate a static thread working area aligned as both position and size.

#define port_init

(

)

Port-related initialization code.

Note

This function is empty in this port.

#define PORT_INT_REQUIRED_STACK   32

Per-thread stack overhead for interrupts servicing.

This constant is used in the calculation of the correct working area size.

#define PORT_IRQ_EPILOGUE

(

)

IRQ epilogue code.

This macro must be inserted at the end of all IRQ handlers enabled to invoke system APIs.

#define PORT_IRQ_HANDLER

(

id

)

ISR(id)

IRQ handler function declaration.

Note

id can be a function name or a vector number depending on the port implementation.

#define PORT_IRQ_PROLOGUE

(

)

IRQ prologue code.

This macro must be inserted at the start of all IRQ handlers enabled to invoke system APIs.

#define port_lock

(

)

asm volatile ("cli" : : : "memory")

Kernel-lock action.

Usually this function just disables interrupts but may perform more actions.

#define port_lock_from_isr

(

)

Kernel-lock action from an interrupt handler.

This function is invoked before invoking I-class APIs from interrupt handlers. The implementation is architecture dependent, in its simplest form it is void.

Note

Same as port_lock() in this port.

#define port_switch	(		ntp,
			otp
	)		_port_switch(ntp, otp)

Performs a context switch between two threads.

This is the most critical code in any port, this function is responsible for the context switch between 2 threads.

Note

The implementation of this code affects directly the context switch performance so optimize here as much as you can.

Parameters

[in]	ntp	the thread to be switched in
[in]	otp	the thread to be switched out

#define port_unlock

(

)

asm volatile ("sei" : : : "memory")

Kernel-unlock action.

Usually this function just enables interrupts but may perform more actions.

#define port_unlock_from_isr

(

)

Kernel-unlock action from an interrupt handler.

This function is invoked after invoking I-class APIs from interrupt handlers. The implementation is architecture dependent, in its simplest form it is void.

Note

Same as port_lock() in this port.

#define port_wait_for_interrupt

(

)

asm volatile ("sleep" : : : "memory")

Enters an architecture-dependent IRQ-waiting mode.

The function is meant to return when an interrupt becomes pending. The simplest implementation is an empty function or macro but this would not take advantage of architecture-specific power saving modes.

Note

Implemented as an inlined WFI instruction.

#define SETUP_CONTEXT	(		tp,
			workspace,
			wsize,
			pf,
			arg
	)

Platform dependent context creation for new threads.

This code usually setup the context switching frame represented by an intctx structure.

Function Documentation

void _port_switch	(	thread_t *	ntp,
		thread_t *	otp
	)

Performs a context switch between two threads.

This is the most critical code in any port, this function is responsible for the context switch between 2 threads.

Note

The implementation of this code affects directly the context switch performance so optimize here as much as you can.

Parameters

[in]	ntp	the thread to be switched in
[in]	otp	the thread to be switched out

void _port_thread_start

(

void

)

Start a thread by invoking its work function.

If the work function returns chThdExit() is automatically invoked.

void boardInit

(

void

)

Board-specific initialization code for Arduino. Use timer 0 compare A to geneate an interrupt every 1024 usec.

NIL_IRQ_HANDLER

(

TIMER0_COMPA_vect

)

System time ISR.

void port_halt

(

void

)

Halts the system.

This function is invoked by the operating system when an unrecoverable error is detected (for example because a programming error in the application code that triggers an assertion while in debug mode).

Note

The function is declared as a weak symbol, it is possible to redefine it in your application code.