/*
ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
/**
* @file chcore.h
* @brief AVR port macros and structures.
*
* @addtogroup AVR_CORE
* @{
*/
#ifndef CHCORE_H
#define CHCORE_H
#include
#include
extern bool __avr_in_isr;
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
/**
* @name Port Capabilities and Constants
* @{
*/
/**
* @brief This port supports a realtime counter.
*/
#define PORT_SUPPORTS_RT FALSE
/**
* @brief Natural alignment constant.
* @note It is the minimum alignment for pointer-size variables.
*/
#define PORT_NATURAL_ALIGN 1U
/**
* @brief Stack alignment constant.
* @note It is the alignement required for the stack pointer.
*/
#define PORT_STACK_ALIGN 1U
/**
* @brief Working Areas alignment constant.
* @note It is the alignment to be enforced for thread working areas.
*/
#define PORT_WORKING_AREA_ALIGN 1U
/** @} */
/**
* @name Architecture and Compiler
* @{
*/
/**
* @brief Macro defining an AVR architecture.
*/
#define PORT_ARCHITECTURE_AVR
/**
* @brief Macro defining the specific AVR architecture.
*/
#define PORT_ARCHITECTURE_AVR_MEGAAVR
/**
* @brief Name of the implemented architecture.
*/
#define PORT_ARCHITECTURE_NAME "MegaAVR"
/**
* @brief Compiler name and version.
*/
#if defined(__GNUC__) || defined(__DOXYGEN__)
#define PORT_COMPILER_NAME "GCC " __VERSION__
#else
#error "unsupported compiler"
#endif
/**
* @brief Port-specific information string.
*/
#define PORT_INFO "None"
/** @} */
/*===========================================================================*/
/* Module pre-compile time settings. */
/*===========================================================================*/
/**
* @brief Stack size for the system idle thread.
* @details This size depends on the idle thread implementation, usually
* the idle thread should take no more space than those reserved
* by @p PORT_INT_REQUIRED_STACK.
*/
#if !defined(PORT_IDLE_THREAD_STACK_SIZE) || defined(__DOXYGEN__)
#define PORT_IDLE_THREAD_STACK_SIZE 8
#endif
/**
* @brief Per-thread stack overhead for interrupts servicing.
* @details This constant is used in the calculation of the correct working
* area size.
*/
#if !defined(PORT_INT_REQUIRED_STACK) || defined(__DOXYGEN__)
#define PORT_INT_REQUIRED_STACK 32
#endif
/**
* @brief Enables an alternative timer implementation.
* @details Usually the port uses a timer interface defined in the file
* @p chcore_timer.h, if this option is enabled then the file
* @p chcore_timer_alt.h is included instead.
*/
#if !defined(PORT_USE_ALT_TIMER) || defined(__DOXYGEN__)
#define PORT_USE_ALT_TIMER FALSE
#endif
/**
* @brief Enables a "wait for interrupt" instruction in the idle loop.
*/
#if !defined(PORT_AVR_WFI_SLEEP_IDLE) || defined(__DOXYGEN__)
#define PORT_AVR_WFI_SLEEP_IDLE FALSE
#endif
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Module data structures and types. */
/*===========================================================================*/
/* The following code is not processed when the file is included from an
asm module.*/
#if !defined(_FROM_ASM_)
/**
* @brief Type of stack and memory alignment enforcement.
* @note In this architecture the stack alignment is enforced to 8 bits.
*/
typedef uint8_t stkalign_t;
/**
* @brief Interrupt saved context.
* @details This structure represents the stack frame saved during a
* preemption-capable interrupt handler.
* @note R2 and R13 are not saved because those are assumed to be immutable
* during the system life cycle.
*/
struct port_extctx {
uint8_t _next;
uint8_t r31;
uint8_t r30;
uint8_t r27;
uint8_t r26;
uint8_t r25;
uint8_t r24;
uint8_t r23;
uint8_t r22;
uint8_t r21;
uint8_t r20;
uint8_t r19;
uint8_t r18;
uint8_t sr;
uint8_t r1;
uint8_t r0;
#if defined(__AVR_3_BYTE_PC__)
uint8_t pcx;
#endif
uint16_t pc;
};
/**
* @brief System saved context.
* @details This structure represents the inner stack frame during a context
* switching.
* @note R2 and R13 are not saved because those are assumed to be immutable
* during the system life cycle.
* @note LR is stored in the caller context so it is not present in this
* structure.
*/
struct port_intctx {
uint8_t _next;
uint8_t r29;
uint8_t r28;
uint8_t r17;
uint8_t r16;
uint8_t r15;
uint8_t r14;
uint8_t r13;
uint8_t r12;
uint8_t r11;
uint8_t r10;
uint8_t r9;
uint8_t r8;
uint8_t r7;
uint8_t r6;
uint8_t r5;
uint8_t r4;
uint8_t r3;
uint8_t r2;
#if defined(__AVR_3_BYTE_PC__)
uint8_t pcx;
#endif
uint8_t pcl;
uint8_t pch;
};
/**
* @brief Platform dependent part of the @p thread_t structure.
* @details This structure usually contains just the saved stack pointer
* defined as a pointer to a @p port_intctx structure.
*/
struct port_context {
struct port_intctx *sp;
};
#endif /* !defined(_FROM_ASM_) */
/*===========================================================================*/
/* Module macros. */
/*===========================================================================*/
/**
* @brief Platform dependent part of the @p chThdCreateI() API.
* @details This code usually setup the context switching frame represented
* by an @p port_intctx structure.
*/
#if defined(__AVR_3_BYTE_PC__) || defined(__DOXYGEN__)
#define PORT_SETUP_CONTEXT(tp, wbase, wtop, pf, arg) { \
tp->ctx.sp = (struct port_intctx *)((uint8_t *)(wtop) - \
sizeof(struct port_intctx)); \
tp->ctx.sp->r2 = (uint8_t)(0xff & (uint16_t)pf); \
tp->ctx.sp->r3 = (uint8_t)((uint16_t)(pf) >> 8); \
tp->ctx.sp->r4 = (uint8_t)(0xff & (uint16_t)arg); \
tp->ctx.sp->r5 = (uint8_t)((uint16_t)(arg) >> 8); \
tp->ctx.sp->pcx = (uint8_t)0; \
tp->ctx.sp->pcl = (uint16_t)_port_thread_start >> 8; \
tp->ctx.sp->pch = (uint8_t)(0xff & (uint16_t)_port_thread_start); \
}
#else /* !__AVR_3_BYTE_PC__ */
#define PORT_SETUP_CONTEXT(tp, wbase, wtop, pf, arg) { \
tp->ctx.sp = (struct port_intctx *)((uint8_t *)(wtop) - \
sizeof(struct port_intctx)); \
tp->ctx.sp->r2 = (uint8_t)(0xff & (uint16_t)pf); \
tp->ctx.sp->r3 = (uint8_t)((uint16_t)(pf) >> 8); \
tp->ctx.sp->r4 = (uint8_t)(0xff & (uint16_t)arg); \
tp->ctx.sp->r5 = (uint8_t)((uint16_t)(arg) >> 8); \
tp->ctx.sp->pcl = (uint16_t)_port_thread_start >> 8; \
tp->ctx.sp->pch = (uint8_t)(0xff & (uint16_t)_port_thread_start); \
}
#endif /* !__AVR_3_BYTE_PC__ */
/**
* @brief Computes the thread working area global size.
* @note There is no need to perform alignments in this macro.
*/
#define PORT_WA_SIZE(n) ((sizeof(struct port_intctx) - 1) + \
(sizeof(struct port_extctx) - 1) + \
((size_t)(n)) + ((size_t)(PORT_INT_REQUIRED_STACK)))
/**
* @brief Static working area allocation.
* @details This macro is used to allocate a static thread working area
* aligned as both position and size.
*
* @param[in] s the name to be assigned to the stack array
* @param[in] n the stack size to be assigned to the thread
*/
#define PORT_WORKING_AREA(s, n) \
stkalign_t s[THD_WORKING_AREA_SIZE(n) / sizeof (stkalign_t)]
/**
* @brief Priority level verification macro.
*/
#define PORT_IRQ_IS_VALID_PRIORITY(n) false
/**
* @brief Priority level verification macro.
*/
#define PORT_IRQ_IS_VALID_KERNEL_PRIORITY(n) false
/**
* @brief IRQ prologue code.
* @details 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.
*/
#define PORT_IRQ_PROLOGUE() { \
asm ("" : : : "r18", "r19", "r20", "r21", "r22", "r23", "r24", \
"r25", "r26", "r27", "r30", "r31"); \
__avr_in_isr = true; \
}
/**
* @brief IRQ epilogue code.
* @details This macro must be inserted at the end of all IRQ handlers
* enabled to invoke system APIs.
*/
#define PORT_IRQ_EPILOGUE() { \
__avr_in_isr = false; \
_dbg_check_lock(); \
if (chSchIsPreemptionRequired()) \
chSchDoReschedule(); \
_dbg_check_unlock(); \
}
/**
* @brief IRQ handler function declaration.
* @note @p id can be a function name or a vector number depending on the
* port implementation.
*/
#define PORT_IRQ_HANDLER(id) ISR(id)
/**
* @brief Fast IRQ handler function declaration.
* @note @p id can be a function name or a vector number depending on the
* port implementation.
*/
#define PORT_FAST_IRQ_HANDLER(id) ISR(id)
/**
* @brief Performs a context switch between two threads.
* @details 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.
*
* @param[in] ntp the thread to be switched in
* @param[in] otp the thread to be switched out
*/
#define port_switch(ntp, otp) { \
_port_switch(ntp, otp); \
asm volatile ("" : : : "memory"); \
}
/**
* @brief Port-related initialization code.
* @note This function is empty in this port.
*/
#define port_init() { \
__avr_in_isr = true; \
}
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
/* The following code is not processed when the file is included from an
asm module.*/
#if !defined(_FROM_ASM_)
#ifdef __cplusplus
extern "C" {
#endif
void _port_switch(thread_t *ntp, thread_t *otp);
void _port_thread_start(void);
#ifdef __cplusplus
}
#endif
#endif /* !defined(_FROM_ASM_) */
/*===========================================================================*/
/* Module inline functions. */
/*===========================================================================*/
/* The following code is not processed when the file is included from an
asm module.*/
#if !defined(_FROM_ASM_)
/**
* @brief Returns a word encoding the current interrupts status.
*
* @return The interrupts status.
*/
static inline syssts_t port_get_irq_status(void) {
return SREG;
}
/**
* @brief Checks the interrupt status.
*
* @param[in] sts the interrupt status word
*
* @return The interrupt status.
* @retval false the word specified a disabled interrupts status.
* @retval true the word specified an enabled interrupts status.
*/
static inline bool port_irq_enabled(syssts_t sts) {
return (bool)((sts & 0x80) != 0);
}
/**
* @brief Determines the current execution context.
*
* @return The execution context.
* @retval false not running in ISR mode.
* @retval true running in ISR mode.
*/
static inline bool port_is_isr_context(void) {
return __avr_in_isr;
}
/**
* @brief Kernel-lock action.
* @details Usually this function just disables interrupts but may perform more
* actions.
*/
static inline void port_lock(void) {
asm volatile ("cli" : : : "memory");
}
/**
* @brief Kernel-unlock action.
* @details Usually this function just enables interrupts but may perform more
* actions.
*/
static inline void port_unlock(void) {
asm volatile ("sei" : : : "memory");
}
/**
* @brief Kernel-lock action from an interrupt handler.
* @details 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.
*/
static inline void port_lock_from_isr(void) {
}
/**
* @brief Kernel-unlock action from an interrupt handler.
* @details 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.
*/
static inline void port_unlock_from_isr(void) {
}
/**
* @brief Disables all the interrupt sources.
* @note Of course non-maskable interrupt sources are not included.
*/
static inline void port_disable(void) {
asm volatile ("cli" : : : "memory");
}
/**
* @brief Disables the interrupt sources below kernel-level priority.
* @note Interrupt sources above kernel level remains enabled.
*/
static inline void port_suspend(void) {
asm volatile ("cli" : : : "memory");
}
/**
* @brief Enables all the interrupt sources.
*/
static inline void port_enable(void) {
asm volatile ("sei" : : : "memory");
}
/**
* @brief Enters an architecture-dependent IRQ-waiting mode.
* @details 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.
*/
static inline void port_wait_for_interrupt(void) {
#if PORT_AVR_WFI_SLEEP_IDLE
asm volatile ("sleep" : : : "memory");
#endif
}
/**
* @brief Returns the current value of the realtime counter.
*
* @return The realtime counter value.
*/
static inline rtcnt_t port_rt_get_counter_value(void) {
return 0;
}
#endif /* !defined(_FROM_ASM_) */
/*===========================================================================*/
/* Module late inclusions. */
/*===========================================================================*/
/* The following code is not processed when the file is included from an
asm module.*/
#if !defined(_FROM_ASM_)
#if CH_CFG_ST_TIMEDELTA > 0
#if !PORT_USE_ALT_TIMER
#include "chcore_timer.h"
#else /* PORT_USE_ALT_TIMER */
#include "chcore_timer_alt.h"
#endif /* PORT_USE_ALT_TIMER */
#endif /* CH_CFG_ST_TIMEDELTA > 0 */
#endif /* !defined(_FROM_ASM_) */
#endif /* CHCORE_H */
/** @} */