From 86f37e7c1b5749a4beff5b6cd0844b3d8d6a63a9 Mon Sep 17 00:00:00 2001 From: barner Date: Fri, 22 Dec 2006 16:55:53 +0000 Subject: [PATCH] AVR specific implementation of contiki multi-threating architecture (supporting per-thread stacks). --- cpu/avr/mtarch.c | 230 +++++++++++++++++++++++++++++++++++++++++++++++ cpu/avr/mtarch.h | 26 ++++-- 2 files changed, 251 insertions(+), 5 deletions(-) create mode 100644 cpu/avr/mtarch.c diff --git a/cpu/avr/mtarch.c b/cpu/avr/mtarch.c new file mode 100644 index 000000000..d9bcd35ec --- /dev/null +++ b/cpu/avr/mtarch.c @@ -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 + * \author Simon Barner + * + * @(#)$Id: mtarch.c,v 1.1 2006/12/22 16:55:53 barner Exp $ + */ + +#include +#include +#include +#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; +} +/*--------------------------------------------------------------------------*/ diff --git a/cpu/avr/mtarch.h b/cpu/avr/mtarch.h index 8b46fd786..eeed5a46d 100644 --- a/cpu/avr/mtarch.h +++ b/cpu/avr/mtarch.h @@ -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 + * \author + * Simon Barner + * + * @(#)$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__ */