62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
#ident "$Id: hello2.c,v 1.4 2004/12/14 22:46:25 hpa Exp $"
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/* ----------------------------------------------------------------------- *
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*
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* Copyright 2002 H. Peter Anvin - All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
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* Boston MA 02111-1307, USA; either version 2 of the License, or
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* (at your option) any later version; incorporated herein by reference.
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*
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* ----------------------------------------------------------------------- */
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/*
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* hello2.c
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*
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* Simple COM32 image
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*
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* This version shows how to use the bounce buffer for data transfer
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* to the BIOS or COMBOOT system calls.
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*/
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#include <com32.h>
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#define NULL ((void *)0)
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static inline void memset(void *buf, int ch, unsigned int len)
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{
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asm volatile("cld; rep; stosb"
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: "+D" (buf), "+c" (len) : "a" (ch) : "memory");
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}
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static void strcpy(char *dst, const char *src)
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{
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while ( *src )
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*dst++ = *src++;
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*dst = '\0';
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}
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static void writemsg(const char *msg)
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{
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com32sys_t inreg;
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memset(&inreg, 0, sizeof inreg);
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strcpy(__com32.cs_bounce, msg);
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inreg.eax.w[0] = 0x0002; /* Write string */
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inreg.ebx.w[0] = OFFS(__com32.cs_bounce);
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inreg.es = SEG(__com32.cs_bounce);
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__com32.cs_intcall(0x22, &inreg, NULL);
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};
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int __start(void)
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{
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writemsg("Hello, World!\r\n"
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"cmdline = ");
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writemsg(__com32.cs_cmdline);
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writemsg("\r\n");
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return 0;
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}
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