Collaboration diagram for Core Port Implementation:

Detailed Description

AVR specific port code, structures and macros.

Data Structures
struct	extctx
	Interrupt saved context. More...
struct	intctx
	System saved context. More...
struct	context
	Platform dependent part of the `Thread` structure. More...
Functions
void	port_switch (Thread ntp, Thread otp)
	Performs a context switch between two threads.
void	port_halt (void)
	Halts the system.
void	_port_thread_start (void)
	Start a thread by invoking its work function.
Defines
#define	ENABLE_WFI_IDLE 0
	If enabled allows the idle thread to enter a low power mode.
#define	CH_ARCHITECTURE_AVR
	Macro defining the AVR architecture.
#define	CH_ARCHITECTURE_NAME "AVR"
	Name of the implemented architecture.
#define	CH_CORE_VARIANT_NAME "MegaAVR"
	Name of the architecture variant (optional).
#define	CH_COMPILER_NAME "GCC " __VERSION__
	Name of the compiler supported by this port.
#define	CH_PORT_INFO "None"
	Port-specific information string.
#define	SETUP_CONTEXT(workspace, wsize, pf, arg)
	Platform dependent part of the `chThdCreateI()` API.
#define	PORT_IDLE_THREAD_STACK_SIZE 8
	Stack size for the system idle thread.
#define	PORT_INT_REQUIRED_STACK 32
	Per-thread stack overhead for interrupts servicing.
#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.
#define	WORKING_AREA(s, n) stkalign_t s[THD_WA_SIZE(n) / sizeof(stkalign_t)]
	Static working area allocation.
#define	PORT_IRQ_PROLOGUE()
	IRQ prologue code.
#define	PORT_IRQ_EPILOGUE()
	IRQ epilogue code.
#define	PORT_IRQ_HANDLER(id) ISR(id)
	IRQ handler function declaration.
#define	port_init()
	Port-related initialization code.
#define	port_lock() asm volatile ("cli" : : : "memory")
	Kernel-lock action.
#define	port_unlock() asm volatile ("sei" : : : "memory")
	Kernel-unlock action.
#define	port_lock_from_isr()
	Kernel-lock action from an interrupt handler.
#define	port_unlock_from_isr()
	Kernel-unlock action from an interrupt handler.
#define	port_disable() asm volatile ("cli" : : : "memory")
	Disables all the interrupt sources.
#define	port_suspend() asm volatile ("cli" : : : "memory")
	Disables the interrupt sources below kernel-level priority.
#define	port_enable() asm volatile ("sei" : : : "memory")
	Enables all the interrupt sources.
#define	port_wait_for_interrupt()
	Enters an architecture-dependent IRQ-waiting mode.
#define	INLINE inline
	Inline function modifier.
#define	ROMCONST const
	ROM constant modifier.
#define	PACK_STRUCT_STRUCT __attribute__((packed))
	Packed structure modifier (within).
#define	PACK_STRUCT_BEGIN
	Packed structure modifier (before).
#define	PACK_STRUCT_END
	Packed structure modifier (after).
Typedefs
typedef uint8_t	stkalign_t
	8 bits stack and memory alignment enforcement.
typedef bool	bool_t
typedef uint8_t	tmode_t
typedef uint8_t	tstate_t
typedef uint8_t	trefs_t
typedef uint8_t	tslices_t
typedef uint8_t	tprio_t
typedef int16_t	msg_t
typedef uint8_t	eventid_t
typedef uint8_t	eventmask_t
typedef uint8_t	flagsmask_t
typedef uint16_t	systime_t
typedef int8_t	cnt_t

Function Documentation

void port_switch	(	Thread *	ntp,
		Thread *	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.; The function is declared as a weak symbol, it is possible to redefine it in your application code.

Parameters:

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

Definition at line 53 of file ports/GCC/AVR/chcore.c.

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.

Definition at line 119 of file ports/GCC/AVR/chcore.c.

References port_disable(), and TRUE.

Here is the call graph for this function:

void _port_thread_start ( void )

Start a thread by invoking its work function.

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

Definition at line 131 of file ports/GCC/AVR/chcore.c.

References chSysUnlock.

Define Documentation

#define ENABLE_WFI_IDLE 0

If enabled allows the idle thread to enter a low power mode.

Definition at line 50 of file ports/GCC/AVR/chcore.h.

#define CH_ARCHITECTURE_AVR

Macro defining the AVR architecture.

Definition at line 56 of file ports/GCC/AVR/chcore.h.

#define CH_ARCHITECTURE_NAME "AVR"

Name of the implemented architecture.

Definition at line 61 of file ports/GCC/AVR/chcore.h.

#define CH_CORE_VARIANT_NAME "MegaAVR"

Name of the architecture variant (optional).

Definition at line 66 of file ports/GCC/AVR/chcore.h.

#define CH_COMPILER_NAME "GCC " __VERSION__

Name of the compiler supported by this port.

Definition at line 71 of file ports/GCC/AVR/chcore.h.

#define CH_PORT_INFO "None"

Port-specific information string.

Definition at line 76 of file ports/GCC/AVR/chcore.h.

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

Value:

{                          \
  tp->p_ctx.sp = (struct intctx*)((uint8_t *)workspace + wsize  -           \
                                  sizeof(struct intctx));                   \
  tp->p_ctx.sp->r2  = (int)pf;                                              \
  tp->p_ctx.sp->r3  = (int)pf >> 8;                                         \
  tp->p_ctx.sp->r4  = (int)arg;                                             \
  tp->p_ctx.sp->r5  = (int)arg >> 8;                                        \
  tp->p_ctx.sp->pcl = (int)_port_thread_start >> 8;                         \
  tp->p_ctx.sp->pch = (int)_port_thread_start;                              \
}

Platform dependent part of the chThdCreateI() API.

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

Definition at line 156 of file ports/GCC/AVR/chcore.h.

#define PORT_IDLE_THREAD_STACK_SIZE 8

Stack size for the system idle thread.

This size depends on the idle thread implementation, usually the idle thread should take no more space than those reserved by PORT_INT_REQUIRED_STACK.

Note:: In this port it is set to 8.

Definition at line 175 of file ports/GCC/AVR/chcore.h.

#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. This value can be zero on those architecture where there is a separate interrupt stack and the stack space between intctx and extctx is known to be zero.

Note:: In this port the default is 32 bytes per thread.

Definition at line 188 of file ports/GCC/AVR/chcore.h.

#define STACK_ALIGN ( n ) ((((n) - 1) | (sizeof(stkalign_t) - 1)) + 1)

Enforces a correct alignment for a stack area size value.

Definition at line 194 of file ports/GCC/AVR/chcore.h.

#define THD_WA_SIZE ( n )

Value:

STACK_ALIGN(sizeof(Thread) +                         \
                                   (sizeof(struct intctx) - 1) +            \
                                   (sizeof(struct extctx) - 1) +            \
                                   (n) + (PORT_INT_REQUIRED_STACK))

Computes the thread working area global size.

Definition at line 199 of file ports/GCC/AVR/chcore.h.

#define 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.

Definition at line 209 of file ports/GCC/AVR/chcore.h.

#define PORT_IRQ_PROLOGUE ( )

Value:

{                                               \
  asm ("" : : : "r18", "r19", "r20", "r21", "r22", "r23", "r24",            \
                "r25", "r26", "r27", "r30", "r31");                         \
}

IRQ prologue code.

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

Note:: This code tricks the compiler to save all the specified registers by "touching" them.

Definition at line 218 of file ports/GCC/AVR/chcore.h.

#define PORT_IRQ_EPILOGUE ( )

Value:

{                                               \
  dbg_check_lock();                                                         \
  if (chSchIsPreemptionRequired())                                          \
    chSchDoReschedule();                                                    \
  dbg_check_unlock();                                                       \
}

IRQ epilogue code.

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

Definition at line 228 of file ports/GCC/AVR/chcore.h.

#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.

Definition at line 240 of file ports/GCC/AVR/chcore.h.

#define port_init ( void )

Port-related initialization code.

Note:: This function is empty in this port.

Definition at line 246 of file ports/GCC/AVR/chcore.h.

#define port_lock ( void ) asm volatile ("cli" : : : "memory")

Kernel-lock action.

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

Note:: Implemented as global interrupt disable.

Definition at line 254 of file ports/GCC/AVR/chcore.h.

#define port_unlock ( void ) asm volatile ("sei" : : : "memory")

Kernel-unlock action.

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

Note:: Implemented as global interrupt enable.

Definition at line 262 of file ports/GCC/AVR/chcore.h.

#define port_lock_from_isr ( void )

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:: This function is empty in this port.

Definition at line 271 of file ports/GCC/AVR/chcore.h.

#define port_unlock_from_isr ( void )

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:: This function is empty in this port.

Definition at line 280 of file ports/GCC/AVR/chcore.h.

#define port_disable ( void ) asm volatile ("cli" : : : "memory")

Disables all the interrupt sources.

Note:: Of course non-maskable interrupt sources are not included.; Implemented as global interrupt disable.

Definition at line 287 of file ports/GCC/AVR/chcore.h.

#define port_suspend ( void ) asm volatile ("cli" : : : "memory")

Disables the interrupt sources below kernel-level priority.

Note:: Interrupt sources above kernel level remains enabled.; Same as port_disable() in this port, there is no difference between the two states.

Definition at line 295 of file ports/GCC/AVR/chcore.h.

#define port_enable ( void ) asm volatile ("sei" : : : "memory")

Enables all the interrupt sources.

Note:: Implemented as global interrupt enable.

Definition at line 301 of file ports/GCC/AVR/chcore.h.

#define port_wait_for_interrupt ( void )

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:: This port function is implemented as inlined code for performance reasons.

Definition at line 317 of file ports/GCC/AVR/chcore.h.

#define INLINE inline

Inline function modifier.

Definition at line 59 of file ports/GCC/AVR/chtypes.h.

#define ROMCONST const

ROM constant modifier.

Note:: It is set to use the "const" keyword in this port.

Definition at line 65 of file ports/GCC/AVR/chtypes.h.

#define PACK_STRUCT_STRUCT __attribute__((packed))

Packed structure modifier (within).

Note:: It uses the "packed" GCC attribute.

Definition at line 71 of file ports/GCC/AVR/chtypes.h.

#define PACK_STRUCT_BEGIN

Packed structure modifier (before).

Note:: Empty in this port.

Definition at line 77 of file ports/GCC/AVR/chtypes.h.

#define PACK_STRUCT_END

Packed structure modifier (after).

Note:: Empty in this port.

Definition at line 83 of file ports/GCC/AVR/chtypes.h.

Typedef Documentation

typedef uint8_t stkalign_t

8 bits stack and memory alignment enforcement.

Definition at line 81 of file ports/GCC/AVR/chcore.h.

typedef bool bool_t

Fast boolean type.

Definition at line 43 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t tmode_t

Thread flags.

Definition at line 44 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t tstate_t

Thread state.

Definition at line 45 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t trefs_t

Thread references counter.

Definition at line 46 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t tslices_t

Thread time slices counter.

Definition at line 47 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t tprio_t

Thread priority.

Definition at line 48 of file ports/GCC/AVR/chtypes.h.

typedef int16_t msg_t

Inter-thread message.

Definition at line 49 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t eventid_t

Event Id.

Definition at line 50 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t eventmask_t

Event mask.

Definition at line 51 of file ports/GCC/AVR/chtypes.h.

typedef uint8_t flagsmask_t

Event flags.

Definition at line 52 of file ports/GCC/AVR/chtypes.h.

typedef uint16_t systime_t

System time.

Definition at line 53 of file ports/GCC/AVR/chtypes.h.

typedef int8_t cnt_t

Resources counter.

Definition at line 54 of file ports/GCC/AVR/chtypes.h.

Detailed Description

Data Structures

Functions

Defines

Typedefs

Function Documentation

Define Documentation

Typedef Documentation