/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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/RT 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 ARMCM3/chcore.h
* @brief ARM Cortex-M3 architecture port macros and structures.
*
* @addtogroup ARMCM3_CORE
* @{
*/
#ifndef _CHCORE_H_
#define _CHCORE_H_
#include "nvic.h"
/*===========================================================================*/
/* Port constants. */
/*===========================================================================*/
/**
* @brief Port implementing a exception mode context switching.
* @details This macro can be used to differentiate this port from the other
* Cortex-Mx port which defines @p CORTEX_PORT_MODE_EXOSWITCH.
*/
#define CORTEX_PORT_MODE_ENDOSWITCH
#define CORTEX_M0 0 /**< @brief Cortex-M0 variant. */
#define CORTEX_M1 1 /**< @brief Cortex-M1 variant. */
#define CORTEX_M3 3 /**< @brief Cortex-M3 variant. */
#define CORTEX_M4 4 /**< @brief Cortex-M4 variant. */
/* Inclusion of the Cortex-Mx implementation specific parameters.*/
#include "cmparams.h"
/* Cortex model check, only M3 right now.*/
#if (CORTEX_MODEL == CORTEX_M3)
#else
#error "unknown or unsupported Cortex-M model"
#endif
/*===========================================================================*/
/* Port derived parameters. */
/*===========================================================================*/
/**
* @brief Priority masking support.
*/
#if defined(CH_ARCHITECTURE_ARM_v7M) || defined(__DOXYGEN__)
#define CORTEX_SUPPORTS_BASEPRI TRUE
#else
#define CORTEX_SUPPORTS_BASEPRI FALSE
#endif
/**
* @brief Total priority levels.
*/
#define CORTEX_PRIORITY_LEVELS (1 << CORTEX_PRIORITY_BITS)
/**
* @brief Minimum priority level.
* @details This minimum priority level is calculated from the number of
* priority bits supported by the specific Cortex-Mx implementation.
*/
#define CORTEX_MINIMUM_PRIORITY (CORTEX_PRIORITY_LEVELS - 1)
/**
* @brief Maximum priority level.
* @details The maximum allowed priority level is always zero.
*/
#define CORTEX_MAXIMUM_PRIORITY 0
/*===========================================================================*/
/* Port macros. */
/*===========================================================================*/
/**
* @brief Priority level verification macro.
*/
#define CORTEX_IS_VALID_PRIORITY(n) \
(((n) >= 0) && ((n) < CORTEX_PRIORITY_LEVELS))
/**
* @brief Priority level to priority mask conversion macro.
*/
#define CORTEX_PRIORITY_MASK(n) ((n) << (8 - CORTEX_PRIORITY_BITS))
/*===========================================================================*/
/* Port configurable parameters. */
/*===========================================================================*/
/**
* @brief Enables the use of the WFI instruction in the idle thread loop.
*/
#ifndef CORTEX_ENABLE_WFI_IDLE
#define CORTEX_ENABLE_WFI_IDLE FALSE
#endif
/**
* @brief SYSTICK handler priority.
* @note The default is calculated as the priority level in the middle
* of the priority range.
*/
#ifndef CORTEX_PRIORITY_SYSTICK
#define CORTEX_PRIORITY_SYSTICK (CORTEX_PRIORITY_LEVELS >> 1)
#else
/* If it is externally redefined then better perform a validity check on it.*/
#if !CORTEX_IS_VALID_PRIORITY(CORTEX_PRIORITY_SYSTICK)
#error "invalid priority level specified for CORTEX_PRIORITY_SYSTICK"
#endif
#endif
/**
* @brief BASEPRI user level.
*/
#ifndef CORTEX_BASEPRI_USER
#define CORTEX_BASEPRI_USER 0
#endif
/**
* @brief BASEPRI level within kernel lock.
* @details Priority levels higher than this one (lower values) are unaffected
* by the OS activity and can be classified as fast interrupt sources,
* see @ref interrupt_classes.
*/
#ifndef CORTEX_BASEPRI_KERNEL
#define CORTEX_BASEPRI_KERNEL CORTEX_PRIORITY_MASK(CORTEX_MAXIMUM_PRIORITY+4)
#endif
/**
* @brief PENDSV handler priority.
* @note This priority must always be the lowest one.
* @note It is recommended, but not mandatory, to leave this priority level
* for this handler alone.
*/
#ifndef CORTEX_PRIORITY_PENDSV
#define CORTEX_PRIORITY_PENDSV CORTEX_MINIMUM_PRIORITY
#endif
/**
* @brief SVCALL handler priority.
* @note This priority must always be one level above the
* @p CORTEX_MAXIMUM_PRIORITY value.
* @note It is recommended, but not mandatory, to leave this priority level
* for this handler alone.
*/
#ifndef CORTEX_PRIORITY_SVCALL
#define CORTEX_PRIORITY_SVCALL (CORTEX_MAXIMUM_PRIORITY + 3)
#endif
/*===========================================================================*/
/* Port exported info. */
/*===========================================================================*/
#if defined(__DOXYGEN__)
/**
* @brief Macro defining the ARM architecture.
*/
#define CH_ARCHITECTURE_ARM_vxm
/**
* @brief Name of the implemented architecture.
*/
#define CH_ARCHITECTURE_NAME "ARMvx-M"
/**
* @brief Name of the architecture variant (optional).
*/
#define CH_CORE_VARIANT_NAME "Cortex-Mx"
#elif CORTEX_MODEL == CORTEX_M4
#define CH_ARCHITECTURE_ARM_v7M
#define CH_ARCHITECTURE_NAME "ARMv7-M"
#define CH_CORE_VARIANT_NAME "Cortex-M4"
#elif CORTEX_MODEL == CORTEX_M3
#define CH_ARCHITECTURE_ARM_v7M
#define CH_ARCHITECTURE_NAME "ARMv7-M"
#define CH_CORE_VARIANT_NAME "Cortex-M3"
#elif CORTEX_MODEL == CORTEX_M1
#define CH_ARCHITECTURE_ARM_v6M
#define CH_ARCHITECTURE_NAME "ARMv6-M"
#define CH_CORE_VARIANT_NAME "Cortex-M1"
#elif CORTEX_MODEL == CORTEX_M0
#define CH_ARCHITECTURE_ARM_v6M
#define CH_ARCHITECTURE_NAME "ARMv6-M"
#define CH_CORE_VARIANT_NAME "Cortex-M0"
#endif
/*===========================================================================*/
/* Port implementation part. */
/*===========================================================================*/
/**
* @brief 32 bits stack and memory alignment enforcement.
*/
typedef uint32_t stkalign_t;
/**
* @brief Generic ARM register.
*/
typedef void *regarm_t;
#if !defined(__DOXYGEN__)
/**
* @brief Interrupt saved context.
* @details This structure represents the stack frame saved during a
* preemption-capable interrupt handler.
* @note This structure is empty in this port.
*/
struct extctx {
};
#endif
#if !defined(__DOXYGEN__)
/**
* @brief System saved context.
* @details This structure represents the inner stack frame during a context
* switching.
*/
struct intctx {
regarm_t basepri;
regarm_t r4;
regarm_t r5;
regarm_t r6;
#ifndef CH_CURRP_REGISTER_CACHE
regarm_t r7;
#endif
regarm_t r8;
regarm_t r9;
regarm_t r10;
regarm_t r11;
regarm_t lr_exc;
/* Start of the hardware saved frame.*/
regarm_t r0;
regarm_t r1;
regarm_t r2;
regarm_t r3;
regarm_t r12;
regarm_t lr_thd;
regarm_t pc;
regarm_t xpsr;
};
#endif
#if !defined(__DOXYGEN__)
/**
* @brief Platform dependent part of the @p Thread structure.
* @details In the Cortex-M3 port this structure just holds a pointer to the
* @p intctx structure representing the stack pointer at the time
* of the context switch.
*/
struct context {
struct intctx *r13;
};
#endif
/**
* @brief Platform dependent part of the @p chThdInit() API.
* @details This code usually setup the context switching frame represented
* by an @p intctx structure.
*/
#define SETUP_CONTEXT(workspace, wsize, pf, arg) { \
tp->p_ctx.r13 = (struct intctx *)((uint8_t *)workspace + \
wsize - \
sizeof(struct intctx)); \
tp->p_ctx.r13->basepri = CORTEX_BASEPRI_USER; \
tp->p_ctx.r13->lr_exc = (regarm_t)0xFFFFFFFD; \
tp->p_ctx.r13->r0 = arg; \
tp->p_ctx.r13->lr_thd = chThdExit; \
tp->p_ctx.r13->pc = pf; \
tp->p_ctx.r13->xpsr = (regarm_t)0x01000000; \
}
/**
* @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 INT_REQUIRED_STACK.
* @note In this port it is set to 4 because the idle thread does have
* a stack frame when compiling without optimizations.
*/
#ifndef IDLE_THREAD_STACK_SIZE
#define IDLE_THREAD_STACK_SIZE 4
#endif
/**
* @brief Per-thread stack overhead for interrupts servicing.
* @details 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 @p intctx and
* @p extctx is known to be zero.
* @note This port requires no extra stack space for interrupt handling.
*/
#ifndef INT_REQUIRED_STACK
#define INT_REQUIRED_STACK 0
#endif
/**
* @brief Enforces a correct alignment for a stack area size value.
*/
#define STACK_ALIGN(n) ((((n) - 1) | (sizeof(stkalign_t) - 1)) + 1)
/**
* @brief Computes the thread working area global size.
*/
#define THD_WA_SIZE(n) STACK_ALIGN(sizeof(Thread) + \
sizeof(struct intctx) + \
sizeof(struct extctx) + \
(n) + (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.
*/
#define WORKING_AREA(s, n) stkalign_t s[THD_WA_SIZE(n) / sizeof(stkalign_t)];
/**
* @brief IRQ prologue code.
* @details This macro must be inserted at the start of all IRQ handlers
* enabled to invoke system APIs.
*/
#define PORT_IRQ_PROLOGUE()
/**
* @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() { \
chSysLockFromIsr(); \
if (chSchIsRescRequiredI()) \
SCB_ICSR = ICSR_PENDSVSET; \
chSysUnlockFromIsr(); \
}
/**
* @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) void id(void)
/**
* @brief Port-related initialization code.
*/
#define port_init() { \
SCB_AIRCR = AIRCR_VECTKEY | AIRCR_PRIGROUP(0); \
NVICSetSystemHandlerPriority(HANDLER_SVCALL, \
CORTEX_PRIORITY_MASK(CORTEX_PRIORITY_SVCALL)); \
NVICSetSystemHandlerPriority(HANDLER_PENDSV, \
CORTEX_PRIORITY_MASK(CORTEX_PRIORITY_PENDSV)); \
NVICSetSystemHandlerPriority(HANDLER_SYSTICK, \
CORTEX_PRIORITY_MASK(CORTEX_PRIORITY_SYSTICK)); \
}
/**
* @brief Kernel-lock action.
* @details Usually this function just disables interrupts but may perform
* more actions.
* @note In this port this it raises the base priority to kernel level.
*/
#if CH_OPTIMIZE_SPEED
#define port_lock() { \
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_KERNEL; \
asm volatile ("msr BASEPRI, %0" : : "r" (tmp)); \
}
#else
#define port_lock() { \
asm volatile ("bl _port_lock" : : : "r3", "lr"); \
}
#endif
/**
* @brief Kernel-unlock action.
* @details Usually this function just disables interrupts but may perform
* more actions.
* @note In this port this it lowers the base priority to kernel level.
*/
#if CH_OPTIMIZE_SPEED
#define port_unlock() { \
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_USER; \
asm volatile ("msr BASEPRI, %0" : : "r" (tmp)); \
}
#else
#define port_unlock() { \
asm volatile ("bl _port_unlock" : : : "r3", "lr"); \
}
#endif
/**
* @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 Same as @p port_lock() in this port.
*/
#define port_lock_from_isr() port_lock()
/**
* @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 Same as @p port_unlock() in this port.
*/
#define port_unlock_from_isr() port_unlock()
/**
* @brief Disables all the interrupt sources.
* @note Of course non maskable interrupt sources are not included.
* @note In this port it disables all the interrupt sources by raising
* the priority mask to level 0.
*/
#define port_disable() asm volatile ("cpsid i")
/**
* @brief Disables the interrupt sources below kernel-level priority.
* @note Interrupt sources above kernel level remains enabled.
* @note In this port it raises/lowers the base priority to kernel level.
*/
#define port_suspend() { \
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_KERNEL; \
asm volatile ("msr BASEPRI, %0 \n\t" \
"cpsie i" : : "r" (tmp)); \
}
/**
* @brief Enables all the interrupt sources.
* @note In this port it lowers the base priority to user level.
*/
#define port_enable() { \
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_USER; \
asm volatile ("msr BASEPRI, %0 \n\t" \
"cpsie i" : : "r" (tmp)); \
}
/**
* @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.
* @note Implemented as an inlined @p WFI instruction.
*/
#if CORTEX_ENABLE_WFI_IDLE || defined(__DOXYGEN__)
#define port_wait_for_interrupt() { \
asm volatile ("wfi"); \
}
#else
#define port_wait_for_interrupt()
#endif
/**
* @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.
* @note Implemented as inlined code for performance reasons.
*
* @param[in] ntp the thread to be switched in
* @param[in] otp the thread to be switched out
*/
static INLINE Thread *port_switch(Thread *ntp, Thread *otp) {
register Thread *_ntp asm ("r0") = (ntp);
register Thread *_otp asm ("r1") = (otp);
#if CH_DBG_ENABLE_STACK_CHECK
register char *sp asm ("sp");
if (sp - sizeof(struct intctx) - sizeof(Thread) < (char *)_otp)
asm volatile ("movs r0, #0 \n\t"
"b chDbgPanic");
#endif /* CH_DBG_ENABLE_STACK_CHECK */
asm volatile ("svc #0" : : "r" (_otp), "r" (_ntp) : "memory");
return _otp;
}
#ifdef __cplusplus
extern "C" {
#endif
void port_halt(void);
#if !CH_OPTIMIZE_SPEED
void _port_lock(void);
void _port_unlock(void);
#endif
#ifdef __cplusplus
}
#endif
#endif /* _CHCORE_H_ */
/** @} */