nes-proj/cpu/6502/mtarch.c

125 lines
4.7 KiB
C
Raw Normal View History

/*
* Copyright (c) 2004, Adam Dunkels.
* 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.
*
* Author: Adam Dunkels <adam@sics.se>
*
* $Id: mtarch.c,v 1.2 2007/08/10 10:45:35 oliverschmidt Exp $
*/
#include <string.h>
#include "mtarch.h"
unsigned char mtarch_asm_threadspreg;
unsigned char *mtarch_asm_threadzp;
unsigned char *mtarch_asm_threadstack;
void mtarch_asm_start(void);
void mtarch_asm_yield(void);
void mtarch_asm_exec(void);
/*--------------------------------------------------------------------------*/
void
mtarch_init(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_remove(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_start(struct mtarch_thread *thread,
void (* function)(void *data),
void *data)
{
memset(thread->cpustack, 0, sizeof(thread->cpustack));
memset(thread->cstack, 0, sizeof(thread->cstack));
/* Copy current zero page content as template. */
mtarch_asm_threadzp = &(thread->zp);
mtarch_asm_start();
/* Create a CPU stack frame with the appropriate values. */
thread->cpustack[MTARCH_CPUSTACKSIZE - 2] = ((unsigned short)function) / 0x100; /* high byte of return address */
thread->cpustack[MTARCH_CPUSTACKSIZE - 3] = ((unsigned short)function) % 0x100; /* low byte of return address */
thread->cpustack[MTARCH_CPUSTACKSIZE - 4] = 0x21; /* processor flags */
thread->cpustack[MTARCH_CPUSTACKSIZE - 5] = /* a register */
thread->cpustack[MTARCH_CPUSTACKSIZE - 6] = /* x register */
thread->cpustack[MTARCH_CPUSTACKSIZE - 7] = 0x00; /* y register */
thread->spreg = MTARCH_CPUSTACKSIZE - 8;
/* Setup the C stack with the data pointer. */
thread->cstack[MTARCH_CSTACKSIZE - 2] = ((unsigned short)data) / 0x100; /* high byte of data pointer */
thread->cstack[MTARCH_CSTACKSIZE - 3] = ((unsigned short)data) % 0x100; /* low byte of data pointer */
/* Setup the C stack pointer. */
thread->zp[1] = ((size_t)&thread->cstack[MTARCH_CSTACKSIZE - 3]) / 0x100; /* high byte of C stack pointer */
thread->zp[0] = ((size_t)&thread->cstack[MTARCH_CSTACKSIZE - 3]) % 0x100; /* low byte of C stack pointer */
}
/*--------------------------------------------------------------------------*/
void
mtarch_yield(void)
{
mtarch_asm_yield();
}
/*--------------------------------------------------------------------------*/
void
mtarch_exec(struct mtarch_thread *thread)
{
/* Switch processor stack. The call to mtarch_asm_switch() will not
return until the process that we switch to calls yield(). */
mtarch_asm_threadspreg = thread->spreg;
mtarch_asm_threadstack = thread->cpustack;
mtarch_asm_threadzp = thread->zp;
mtarch_asm_exec();
thread->spreg = mtarch_asm_threadspreg;
}
/*--------------------------------------------------------------------------*/
void
mtarch_stop(struct mtarch_thread *thread)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_pstart(void)
{
}
/*--------------------------------------------------------------------------*/
void
mtarch_pstop(void)
{
}
/*--------------------------------------------------------------------------*/