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/*
ChibiOS/NIL - Copyright (C) 2013,2014 Giovanni Di Sirio.
This file is part of ChibiOS/NIL.
ChibiOS/NIL 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/NIL 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 <http://www.gnu.org/licenses/>.
*/
/**
* @file chcore_v6m.h
* @brief ARMv6-M architecture port macros and structures.
*
* @addtogroup ARMCMx_V6M_CORE
* @{
*/
#ifndef _CHCORE_V6M_H_
#define _CHCORE_V6M_H_
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
/**
* @name Architecture and Compiler
* @{
*/
#if (CORTEX_MODEL == CORTEX_M0) || defined(__DOXYGEN__)
/**
* @brief Macro defining the specific ARM architecture.
*/
#define PORT_ARCHITECTURE_ARM_v6M
/**
* @brief Name of the implemented architecture.
*/
#define PORT_ARCHITECTURE_NAME "ARMv6-M"
/**
* @brief Name of the architecture variant.
*/
#define PORT_CORE_VARIANT_NAME "Cortex-M0"
#elif (CORTEX_MODEL == CORTEX_M0PLUS)
#define PORT_ARCHITECTURE_ARM_v6M
#define PORT_ARCHITECTURE_NAME "ARMv6-M"
#define PORT_CORE_VARIANT_NAME "Cortex-M0+"
#endif
/**
* @brief Port-specific information string.
*/
#if !CORTEX_ALTERNATE_SWITCH || defined(__DOXYGEN__)
#define PORT_INFO "Preemption through NMI"
#else
#define PORT_INFO "Preemption through PendSV"
#endif
/** @} */
/**
* @brief This port does not support a realtime counter.
*/
#define PORT_SUPPORTS_RT FALSE
/**
* @brief PendSV priority level.
* @note This priority is enforced to be equal to @p 0,
* this handler always has the highest priority that cannot preempt
* the kernel.
*/
#define CORTEX_PRIORITY_PENDSV 0
/*===========================================================================*/
/* 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.
* @note In this port it is set to 16 because the idle thread does have
* a stack frame when compiling without optimizations. You may
* reduce this value to zero when compiling with optimizations.
*/
#if !defined(PORT_IDLE_THREAD_STACK_SIZE)
#define PORT_IDLE_THREAD_STACK_SIZE 16
#endif
/**
* @brief Per-thread stack overhead for interrupts servicing.
* @details This constant is used in the calculation of the correct working
* area size.
* @note In this port this value is conservatively set to 32 because the
* function @p chSchDoReschedule() can have a stack frame, especially
* with compiler optimizations disabled. The value can be reduced
* when compiler optimizations are enabled.
*/
#if !defined(PORT_INT_REQUIRED_STACK)
#define PORT_INT_REQUIRED_STACK 32
#endif
/**
* @brief Enables the use of the WFI instruction in the idle thread loop.
*/
#if !defined(CORTEX_ENABLE_WFI_IDLE)
#define CORTEX_ENABLE_WFI_IDLE FALSE
#endif
/**
* @brief Alternate preemption method.
* @details Activating this option will make the Kernel use the PendSV
* handler for preemption instead of the NMI handler.
*/
#ifndef CORTEX_ALTERNATE_SWITCH
#define CORTEX_ALTERNATE_SWITCH FALSE
#endif
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/**
* @brief Maximum usable priority for normal ISRs.
*/
#if CORTEX_ALTERNATE_SWITCH || defined(__DOXYGEN__)
#define CORTEX_MAX_KERNEL_PRIORITY 1
#else
#define CORTEX_MAX_KERNEL_PRIORITY 0
#endif
/*===========================================================================*/
/* Module data structures and types. */
/*===========================================================================*/
#if !defined(_FROM_ASM_)
/* The documentation of the following declarations is in chconf.h in order
to not have duplicated structure names into the documentation.*/
#if !defined(__DOXYGEN__)
struct port_extctx {
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;
};
struct port_intctx {
regarm_t r8;
regarm_t r9;
regarm_t r10;
regarm_t r11;
regarm_t r4;
regarm_t r5;
regarm_t r6;
regarm_t r7;
regarm_t lr;
};
#endif /* !defined(__DOXYGEN__) */
/*===========================================================================*/
/* Module macros. */
/*===========================================================================*/
/**
* @brief Platform dependent thread stack setup.
* @details This code usually setup the context switching frame represented
* by an @p port_intctx structure.
*/
#define PORT_SETUP_CONTEXT(tp, wend, pf, arg) { \
(tp)->ctxp = (struct port_intctx *)(((uint8_t *)(wend)) - \
sizeof(struct port_intctx)); \
(tp)->ctxp->r4 = (regarm_t)(pf); \
(tp)->ctxp->r5 = (regarm_t)(arg); \
(tp)->ctxp->lr = (regarm_t)(_port_thread_start); \
}
/**
* @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) + \
sizeof(struct port_extctx) + \
(n) + (PORT_INT_REQUIRED_STACK))
/**
* @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() \
regarm_t _saved_lr; \
asm volatile ("mov %0, lr" : "=r" (_saved_lr) : : "memory")
/**
* @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() _port_irq_epilogue(_saved_lr)
/**
* @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 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) void id(void)
/**
* @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 <b>directly</b> 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
*/
#if !NIL_CFG_ENABLE_STACK_CHECK || defined(__DOXYGEN__)
#define port_switch(ntp, otp) _port_switch(ntp, otp)
#else
#define port_switch(ntp, otp) { \
struct port_intctx *r13 = (struct port_intctx *)__get_PSP(); \
if ((stkalign_t *)(r13 - 1) < (otp)->stklim) \
chSysHalt("stack overflow"); \
_port_switch(ntp, otp); \
}
#endif
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#ifdef __cplusplus
extern "C" {
#endif
void _port_irq_epilogue(regarm_t lr);
void _port_switch_from_isr(void);
void _port_exit_from_isr(void);
void _port_switch(thread_t *ntp, thread_t *otp);
void _port_thread_start(void);
#ifdef __cplusplus
}
#endif
/*===========================================================================*/
/* Module inline functions. */
/*===========================================================================*/
/**
* @brief Port-related initialization code.
*/
static inline void port_init(void) {
NVIC_SetPriority(PendSV_IRQn, CORTEX_PRIORITY_PENDSV);
}
/**
* @brief Returns a word encoding the current interrupts status.
*
* @return The interrupts status.
*/
static inline syssts_t port_get_irq_status(void) {
return (syssts_t)__get_PRIMASK();
}
/**
* @brief Checks the interrupt status.
*
* @param[in] sts the interrupt status word
*
* @return The interrupt status.
* @retvel false the word specified a disabled interrupts status.
* @retvel true the word specified an enabled interrupts status.
*/
static inline bool port_irq_enabled(syssts_t sts) {
return (sts & 1) == 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 (bool)((__get_IPSR() & 0x1FF) != 0);
}
/**
* @brief Kernel-lock action.
* @details In this port this function disables interrupts globally.
*/
static inline void port_lock(void) {
__disable_irq();
}
/**
* @brief Kernel-unlock action.
* @details In this port this function enables interrupts globally.
*/
static inline void port_unlock(void) {
__enable_irq();
}
/**
* @brief Kernel-lock action from an interrupt handler.
* @details In this port this function disables interrupts globally.
* @note Same as @p port_lock() in this port.
*/
static inline void port_lock_from_isr(void) {
port_lock();
}
/**
* @brief Kernel-unlock action from an interrupt handler.
* @details In this port this function enables interrupts globally.
* @note Same as @p port_lock() in this port.
*/
static inline void port_unlock_from_isr(void) {
port_unlock();
}
/**
* @brief Disables all the interrupt sources.
*/
static inline void port_disable(void) {
__disable_irq();
}
/**
* @brief Disables the interrupt sources below kernel-level priority.
*/
static inline void port_suspend(void) {
__disable_irq();
}
/**
* @brief Enables all the interrupt sources.
*/
static inline void port_enable(void) {
__enable_irq();
}
/**
* @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.
*/
static inline void port_wait_for_interrupt(void) {
#if CORTEX_ENABLE_WFI_IDLE
__WFI;
#endif
}
#endif /* _FROM_ASM_ */
#endif /* _CHCORE_V6M_H_ */
/** @} */
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