#ident "$Id$" /* ----------------------------------------------------------------------- * * * Copyright 2002 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, * Bostom MA 02111-1307, USA; either version 2 of the License, or * (at your option) any later version; incorporated herein by reference. * * ----------------------------------------------------------------------- */ /* * hello2.c * * Simple COM32 image * * This version shows how to use the bounce buffer for data transfer * to the BIOS or COMBOOT system calls. */ #include #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"); } static inline void memcpy(void *dst, const void *src, unsigned int len) { asm volatile("cld; rep; movsb" : "+D" (dst), "+S" (src), "+c" (len) : : "memory"); } int __start(void) { const char msg[] = "Hello, World!\r\n"; com32sys_t inreg, outreg; const char *p; memset(&inreg, 0, sizeof inreg); /* Bounce buffer is at least 64K in size */ memcpy(__com32.cs_bounce, msg, sizeof msg); inreg.eax.w[0] = 0x0002; /* Write string */ inreg.ebx.w[0] = OFFS(__com32.cs_bounce); inreg.es = SEG(__com32.cs_bounce); __com32.cs_syscall(0x22, &inreg, NULL); return 0; }