sample/hello.c

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2002-2008 H. Peter Anvin - All Rights Reserved
 *
 *   This program 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, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * hello.c
 *
 * Simple COM32 image
 */

#include <com32.h>

#define NULL ((void *)0)

static inline void memset(void *buf, int ch, unsigned int len)
{
    asm volatile ("cld; rep; stosb":"+D" (buf), "+c"(len):"a"(ch):"memory");
}

int __start(void)
{
    const char *msg = "Hello, World!\r\n";
    com32sys_t inreg;
    const char *p;

    memset(&inreg, 0, sizeof inreg);

    for (p = msg; *p; p++) {
	inreg.edx.b[0] = *p;
	inreg.eax.b[1] = 0x02;	/* Write Character */
	__com32.cs_intcall(0x21, &inreg, NULL);
    }

    return 0;
}