/*
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_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 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 sizeof (void *)
/**
* @brief Stack alignment constant.
* @note It is the alignement required for the stack pointer.
*/
#define PORT_STACK_ALIGN sizeof (stkalign_t)
/**
* @brief Working Areas alignment constant.
* @note It is the alignment to be enforced for thread working areas.
*/
#define PORT_WORKING_AREA_ALIGN PORT_STACK_ALIGN
/** @} */
/**
* @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 64 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 64
#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. */
/*===========================================================================*/
#if !defined(CH_CUSTOMER_LIC_PORT_CM0)
#error "CH_CUSTOMER_LIC_PORT_CM0 not defined"
#endif
#if CH_CUSTOMER_LIC_PORT_CM0 == FALSE
#error "ChibiOS Cortex-M0 port not licensed"
#endif
/* Handling a GCC problem impacting ARMv6-M.*/
#if defined(__GNUC__) && !defined(PORT_IGNORE_GCC_VERSION_CHECK)
#if __GNUC__ > 5
#warning "This compiler has a know problem with Cortex-M0, see bugs: 88167, 88656."
#warning "*** Use GCC version 5 or below ***"
#endif
#endif
/**
* @name Architecture and Compiler
* @{
*/
#if ((CORTEX_MODEL == 0) && !defined(__CORE_CM0PLUS_H_DEPENDANT)) || \
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 == 0) && defined(__CORE_CM0PLUS_H_DEPENDANT)
#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 == FALSE) || defined(__DOXYGEN__)
#define PORT_INFO "Preemption through NMI"
#else
#define PORT_INFO "Preemption through PendSV"
#endif
/** @} */
/**
* @brief Maximum usable priority for normal ISRs.
*/
#if (CORTEX_ALTERNATE_SWITCH == TRUE) || 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 part of the @p chThdCreateI() API.
* @details This code usually setup the context switching frame represented
* by an @p port_intctx structure.
*/
#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->r4 = (regarm_t)(pf); \
(tp)->ctx.sp->r5 = (regarm_t)(arg); \
(tp)->ctx.sp->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) + \
((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 IRQ prologue code.
* @details This macro must be inserted at the start of all IRQ handlers
* enabled to invoke system APIs.
*/
#if defined(__GNUC__) || defined(__DOXYGEN__)
#define PORT_IRQ_PROLOGUE() \
regarm_t _saved_lr = (regarm_t)__builtin_return_address(0)
#elif defined(__ICCARM__)
#define PORT_IRQ_PROLOGUE() \
regarm_t _saved_lr = (regarm_t)__get_LR()
#elif defined(__CC_ARM)
#define PORT_IRQ_PROLOGUE() \
regarm_t _saved_lr = (regarm_t)__return_address()
#endif
/**
* @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.
*/
#ifdef __cplusplus
#define PORT_IRQ_HANDLER(id) extern "C" void id(void)
#else
#define PORT_IRQ_HANDLER(id) void id(void)
#endif
/**
* @brief Fast IRQ handler function declaration.
* @note @p id can be a function name or a vector number depending on the
* port implementation.
*/
#ifdef __cplusplus
#define PORT_FAST_IRQ_HANDLER(id) extern "C" void id(void)
#else
#define PORT_FAST_IRQ_HANDLER(id) void id(void)
#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.
*
* @param[in] ntp the thread to be switched in
* @param[in] otp the thread to be switched out
*/
#if (CH_DBG_ENABLE_STACK_CHECK == FALSE) || 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)->wabase) { \
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(thread_t *ntp, thread_t *otp);
void _port_thread_start(void);
void _port_switch_from_isr(void);
void _port_exit_from_isr(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.
* @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 (sts & (syssts_t)1) == (syssts_t)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() & 0x1FFU) != 0U);
}
/**
* @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 == TRUE
__WFI();
#endif
}
#endif /* _FROM_ASM_ */
#endif /* CHCORE_V6M_H */
/** @} */