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AVR specific implementation of contiki multi-threating architecture

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(supporting per-thread stacks).
This commit is contained in:
barner 2006-12-22 16:55:53 +00:00
parent 265f45feba
commit 86f37e7c1b
2 changed files with 251 additions and 5 deletions
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230
cpu/avr/mtarch.c Normal file
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@ -0,0 +1,230 @@
/*
* Copyright (c) 2006, Technical University of Munich
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* \file AVR specific implementation of multithreading architecture
*
* \author Adam Dunkels <adam@sics.se>
* \author Simon Barner <barner@in.tum.de>
*
* @(#)$Id: mtarch.c,v 1.1 2006/12/22 16:55:53 barner Exp $
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdio.h>
#include "sys/mt.h"
#include "dev/rs232.h"
/*--------------------------------------------------------------------------*/
void
mtarch_init(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_start(struct mtarch_thread *t,
void (*function)(void *), void *data)
{
/* Initialize stack with number sequence (used for
* measuring stack usage */
uint8_t i;
for(i = 0; i < MTARCH_STACKSIZE; ++i) {
t->stack[i] = i;
}
/*
* Push pointer to mt_exit and the thread onto our stack:
* Caveats:
* - The stack is defined as an array of bytes, but pointers are 16 bit wide
* - Function pointers are 16-bit addresses in flash ROM, but e.g.
* avr-objdump displays byte addresses
* - Get the high and low byte of the addresses onto the stack in the
* right order
*/
/* Initialize stack. This is done in reverse order ("pushing") the
* pre-allocated array */
/* mt_exit function that is to be invoked if the thread dies */
t->stack[MTARCH_STACKSIZE - 1] = (unsigned char)((unsigned short)mt_exit) & 0xff;
t->stack[MTARCH_STACKSIZE - 2] = (unsigned char)((unsigned short)mt_exit >> 8) & 0xff;
/* The thread handler. Invoked when RET is called in mtarch_exec */
t->stack[MTARCH_STACKSIZE - 3] = (unsigned char)((unsigned short)function) & 0xff;
t->stack[MTARCH_STACKSIZE - 4] = (unsigned char)((unsigned short)function >> 8) & 0xff;
/* Register r0-r23 in t->stack[MTARCH_STACKSIZE - 5] to
* t->stack[MTARCH_STACKSIZE - 28].
*
* Per calling convention, the argument to the thread handler function
* (i.e. the 'data' pointer) is passed via r24-r25.
* See http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_reg_usage) */
t->stack[MTARCH_STACKSIZE - 29] = (unsigned char)((unsigned short)data) & 0xff;
t->stack[MTARCH_STACKSIZE - 30] = (unsigned char)((unsigned short)data >> 8) & 0xff;
/* Initialize stack pointer: Space for 2 2-byte-addresses and 32 registers,
* post-decrement POP / pre-increment PUSH scheme */
t->sp = &t->stack[MTARCH_STACKSIZE - 1 - 4 - 32];
}
/*--------------------------------------------------------------------------*/
static unsigned char *sptmp;
static struct mtarch_thread *running;
static void
sw(void)
{
/* Disable interrupts while we perform the context switch */
cli ();
/* Push 32 general purpuse registers */
__asm__("push r0");
__asm__("push r1");
__asm__("push r2");
__asm__("push r3");
__asm__("push r4");
__asm__("push r5");
__asm__("push r6");
__asm__("push r7");
__asm__("push r8");
__asm__("push r9");
__asm__("push r10");
__asm__("push r11");
__asm__("push r12");
__asm__("push r13");
__asm__("push r14");
__asm__("push r15");
__asm__("push r16");
__asm__("push r17");
__asm__("push r18");
__asm__("push r19");
__asm__("push r20");
__asm__("push r21");
__asm__("push r22");
__asm__("push r23");
__asm__("push r24");
__asm__("push r25");
__asm__("push r26");
__asm__("push r27");
__asm__("push r28");
__asm__("push r29");
__asm__("push r30");
__asm__("push r31");
/* Switch stack pointer */
sptmp = running->sp;
running->sp = (unsigned char*)SP;
SP = (unsigned short)sptmp;
/* Pop 32 general purpose registers */
__asm__("pop r31");
__asm__("pop r30");
__asm__("pop r29");
__asm__("pop r28");
__asm__("pop r27");
__asm__("pop r26");
__asm__("pop r25");
__asm__("pop r24");
__asm__("pop r23");
__asm__("pop r22");
__asm__("pop r21");
__asm__("pop r20");
__asm__("pop r19");
__asm__("pop r18");
__asm__("pop r17");
__asm__("pop r16");
__asm__("pop r15");
__asm__("pop r14");
__asm__("pop r13");
__asm__("pop r12");
__asm__("pop r11");
__asm__("pop r10");
__asm__("pop r9");
__asm__("pop r8");
__asm__("pop r7");
__asm__("pop r6");
__asm__("pop r5");
__asm__("pop r4");
__asm__("pop r3");
__asm__("pop r2");
__asm__("pop r1");
__asm__("pop r0");
/* Renable interrupts */
sei ();
}
/*--------------------------------------------------------------------------*/
void
mtarch_exec(struct mtarch_thread *t)
{
running = t;
sw();
running = NULL;
}
/*--------------------------------------------------------------------------*/
void
mtarch_remove(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_yield(void)
{
sw();
}
/*--------------------------------------------------------------------------*/
void
mtarch_pstop(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_pstart(void)
{
}
/*--------------------------------------------------------------------------*/
int
mtarch_stack_usage(struct mt_thread *t)
{
uint8_t i;
for(i = 0; i < MTARCH_STACKSIZE; ++i) {
if(t->thread.stack[i] != i) {
break;
}
}
return MTARCH_STACKSIZE - i;
}
/*--------------------------------------------------------------------------*/

26
cpu/avr/mtarch.h
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@ -27,17 +27,33 @@
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* @(#)$Id: mtarch.h,v 1.1 2006/06/20 21:23:09 adamdunkels Exp $
*/
/**
* \file
* AVR specific implementation of multithreading architecture
* \author
* Adam Dunkels <adam@sics.se>
* \author
* Simon Barner <barner@in.tum.de>
*
* @(#)$Id: mtarch.h,v 1.2 2006/12/22 16:55:53 barner Exp $
*/
#ifndef __MTARCH_H__
#define __MTARCH_H__
#define MTARCH_STACKSIZE 64
#include "contiki-conf.h"
#ifdef MTARCH_CONF_STACKSIZE
#define MTARCH_STACKSIZE MTARCH_CONF_STACKSIZE
#else
#define MTARCH_STACKSIZE 128
#endif
struct mtarch_thread {
unsigned short stack[MTARCH_STACKSIZE];
unsigned short *sp;
unsigned char stack[MTARCH_STACKSIZE];
unsigned char *sp;
};
#endif /* __MTARCH_H__ */