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/*
ChibiOS/RT - Copyright (C) 2006-2007 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 <http://www.gnu.org/licenses/>.
*/
/**
* @addtogroup AVR_CORE
* @{
*/
#ifndef _CHCORE_H_
#define _CHCORE_H_
#include <avr/io.h>
#include <avr/interrupt.h>
/**
* If enabled allows the idle thread to enter a low power mode.
*/
#ifndef ENABLE_WFI_IDLE
#define ENABLE_WFI_IDLE 0
#endif
/**
* Macro defining the AVR architecture.
*/
#define CH_ARCHITECTURE_AVR
/**
* 8 bit stack alignment.
*/
typedef uint8_t stkalign_t;
/** @cond never */
/**
* Interrupt saved context.
* @note The field @p _next is not part of the context, it represents the
* offset of the structure relative to the stack pointer.
*/
struct 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;
uint16_t pc;
};
/** @endcond */
/** @cond never */
/**
* System saved context.
* @note The field @p _next is not part of the context, it represents the
* offset of the structure relative to the stack pointer.
*/
struct 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;
#ifndef CH_CURRP_REGISTER_CACHE
uint8_t r9;
uint8_t r8;
#endif
uint8_t r7;
uint8_t r6;
uint8_t r5;
uint8_t r4;
uint8_t r3;
uint8_t r2;
uint8_t pcl;
uint8_t pch;
};
/** @endcond */
/** @cond never */
/**
* In the AVR 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 *sp;
};
/** @endcond */
/**
* Platform dependent part of the @p chThdInit() API.
* This code usually setup the context switching frame represented by a
* @p intctx structure.
*/
#define SETUP_CONTEXT(workspace, wsize, pf, arg) { \
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)threadstart >> 8; \
tp->p_ctx.sp->pch = (int)threadstart; \
}
/**
* The default idle thread implementation requires no extra stack space in
* this port.
*/
#ifndef IDLE_THREAD_STACK_SIZE
#define IDLE_THREAD_STACK_SIZE 8
#endif
/**
* Per-thread stack overhead for interrupts servicing, it is used in the
* calculation of the correct working area size. In this port the default is
* 32 bytes per thread.
*/
#ifndef INT_REQUIRED_STACK
#define INT_REQUIRED_STACK 32
#endif
/**
* Enforces a correct alignment for a stack area size value.
*/
#define STACK_ALIGN(n) ((((n) - 1) | sizeof(stkalign_t)) + 1)
/**
* Computes the thread working area global size.
*/
#define THD_WA_SIZE(n) STACK_ALIGN(sizeof(Thread) + \
(sizeof(struct intctx) - 1) + \
(sizeof(struct extctx) - 1) + \
(n) + (INT_REQUIRED_STACK))
/**
* Macro used to allocate a thread working area aligned as both position and
* size.
*/
#define WORKING_AREA(s, n) stkalign_t s[THD_WA_SIZE(n) / sizeof(stkalign_t)];
/**
* IRQ prologue code, inserted at the start of all IRQ handlers enabled to
* invoke system APIs.
* 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"); \
}
/**
* IRQ epilogue code, inserted at the end of all IRQ handlers enabled to
* invoke system APIs.
*/
#define PORT_IRQ_EPILOGUE() { \
if (chSchRescRequiredI()) \
chSchDoRescheduleI(); \
}
/**
* IRQ handler function modifier. Note, it just aliases the WinAVR "ISR"
* macro.
*/
#define PORT_IRQ_HANDLER ISR
/**
* This function is empty in this port.
*/
#define port_init()
/**
* Implemented as global interrupt disable.
*/
#define port_lock() asm volatile ("cli")
/**
* Implemented as global interrupt enable.
*/
#define port_unlock() asm volatile ("sei")
/**
* This function is empty in this port.
*/
#define port_lock_from_isr()
/**
* This function is empty in this port.
*/
#define port_unlock_from_isr()
/**
* Implemented as global interrupt disable.
*/
#define port_disable() asm volatile ("cli")
/**
* Same as @p port_disable() in this port, there is no difference between the
* two states.
*/
#define port_suspend() asm volatile ("cli")
/**
* Implemented as global interrupt enable.
*/
#define port_enable() asm volatile ("sei")
/**
* This port function is implemented as inlined code for performance reasons.
*/
#if ENABLE_WFI_IDLE != 0
#define port_wait_for_interrupt() { \
asm volatile ("sleep"); \
}
#else
#define port_wait_for_interrupt()
#endif
#ifdef __cplusplus
extern "C" {
#endif
void port_puts(char *msg);
void port_switch(Thread *otp, Thread *ntp);
void port_halt(void);
void threadstart(void);
#ifdef __cplusplus
}
#endif
#endif /* _CHCORE_H_ */
/** @} */
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