cooja_mtarch.c

/*
 * Copyright (c) 2005, Swedish Institute of Computer Science
 * 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.
 *
 */

#include <stddef.h>

#include <limits.h>
#include <stdio.h>
#include <string.h>
#include "sys/cooja_mt.h"

#if INTPTR_MAX == INT32_MAX
#define ON_64BIT_ARCH 0
#elif INTPTR_MAX == INT64_MAX
#define ON_64BIT_ARCH 1
#else
#error "Could not detect 32/64-bit environment."
#endif

struct frame {
  uintptr_t flags;
#if ON_64BIT_ARCH
  uintptr_t rbp;
  uintptr_t rdi;
  uintptr_t rsi;
  uintptr_t rdx;
  uintptr_t rcx;
  uintptr_t rbx;
  uintptr_t rax;
#else /* ON_64BIT_ARCH */
  uintptr_t ebp;
  uintptr_t edi;
  uintptr_t esi;
  uintptr_t edx;
  uintptr_t ecx;
  uintptr_t ebx;
  uintptr_t eax;
#endif /* ON_64BIT_ARCH */
  uintptr_t retaddr;
  uintptr_t retaddr2;
  uintptr_t data;
};

/*--------------------------------------------------------------------------*/
void
cooja_mtarch_start(struct cooja_mtarch_thread *t,
    void (*function)(void *), void *data)
{
  struct frame *f = (struct frame *)&t->stack[COOJA_MTARCH_STACKSIZE - sizeof(struct frame)/sizeof(uintptr_t)];
  int i;

  for(i = 0; i < COOJA_MTARCH_STACKSIZE; ++i) {
    t->stack[i] = i;
  }

  memset(f, 0, sizeof(struct frame));
  f->retaddr = (uintptr_t)function;
  f->data    = (uintptr_t)data;
  t->sp      = (uintptr_t)&f->flags;
#if ON_64BIT_ARCH
  f->rbp     = (uintptr_t)&f->rax;
#else /* ON_64BIT_ARCH */
  f->ebp     = (uintptr_t)&f->eax;
#endif /* ON_64BIT_ARCH */
}
/*--------------------------------------------------------------------------*/
static struct cooja_mtarch_thread *cooja_running_thread;
/*--------------------------------------------------------------------------*/
void cooja_sw(void)
{
  /* Store registers */
#if ON_64BIT_ARCH
  __asm__ (
      "pushq %rax\n\t"
      "pushq %rbx\n\t"
      "pushq %rcx\n\t"
      "pushq %rdx\n\t"
      "pushq %rsi\n\t"
      "pushq %rdi\n\t"
      "pushq %rbp\n\t"
      "pushq %rbp\n\t");
#else /* ON_64BIT_ARCH */
  __asm__ (
      "pushl %eax\n\t"
      "pushl %ebx\n\t"
      "pushl %ecx\n\t"
      "pushl %edx\n\t"
      "pushl %esi\n\t"
      "pushl %edi\n\t"
      "pushl %ebp\n\t"
      "pushl %ebp\n\t");
#endif /* ON_64BIT_ARCH */

  /* Switch stack pointer */
#if ON_64BIT_ARCH
  __asm__ ("movq %0, %%rax\n\t" : : "m" (cooja_running_thread));
  __asm__ (
      "movq (%rax), %rbx\n\t"
      "movq %rsp, (%rax)\n\t"
      "movq %rbx, %rsp\n\t"
  );
#else /* ON_64BIT_ARCH */
  __asm__ ("movl %0, %%eax\n\t" : : "m" (cooja_running_thread));
  __asm__ (
      "movl (%eax), %ebx\n\t"
      "movl %esp, (%eax)\n\t"
      "movl %ebx, %esp\n\t"
  );
#endif /* ON_64BIT_ARCH */

  /* Restore previous registers */
#if ON_64BIT_ARCH
  __asm__ (
      "popq %rbp\n\t"
      "popq %rbp\n\t"
      "popq %rdi\n\t"
      "popq %rsi\n\t"
      "popq %rdx\n\t"
      "popq %rcx\n\t"
      "popq %rbx\n\t"
      "popq %rax\n\t"

      "leave\n\t"
      "ret\n\t"
  );
#else /* ON_64BIT_ARCH */
  __asm__ (
      "popl %ebp\n\t"
      "popl %ebp\n\t"
      "popl %edi\n\t"
      "popl %esi\n\t"
      "popl %edx\n\t"
      "popl %ecx\n\t"
      "popl %ebx\n\t"
      "popl %eax\n\t"

      "leave\n\t"
      "ret\n\t"
  );
#endif /* ON_64BIT_ARCH */

}

/*--------------------------------------------------------------------------*/
void
cooja_mtarch_exec(struct cooja_mtarch_thread *t)
{
  cooja_running_thread = t;
  cooja_sw();
  cooja_running_thread = NULL;
}
/*--------------------------------------------------------------------------*/
void
cooja_mtarch_yield(void)
{
  cooja_sw();
}
/*--------------------------------------------------------------------------*/