61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
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/*
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* mbx-inbyte.c -- inbyte function for targets using the eppcbug monitor
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*
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* Copyright (c) 1998 Cygnus Support
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*
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* The authors hereby grant permission to use, copy, modify, distribute,
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* and license this software and its documentation for any purpose, provided
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* that existing copyright notices are retained in all copies and that this
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* notice is included verbatim in any distributions. No written agreement,
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* license, or royalty fee is required for any of the authorized uses.
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* Modifications to this software may be copyrighted by their authors
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* and need not follow the licensing terms described here, provided that
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* the new terms are clearly indicated on the first page of each file where
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* they apply.
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*/
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#include "ppc-asm.h"
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int inbyte(void)
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{
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struct {
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unsigned clun;
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unsigned dlun;
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char *data;
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unsigned len;
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unsigned rsrvd;
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char buf[4];
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} ipb, *inpb;
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struct {
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int status;
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int cnt;
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} opb, *outpb;
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inpb = &ipb;
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outpb = &opb;
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do {
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inpb->clun = 0;
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inpb->dlun = 0;
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inpb->data = ipb.buf;
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inpb->len = 1;
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inpb->rsrvd = 0;
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asm volatile (
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"mr 3,%0\n"
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"mr 4,%1\n"
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"li 10,0x200\n"
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"sc"
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: /* no outputs */
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: "r" (inpb), "r" (outpb)
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: "3", "4", "10"
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);
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} while (outpb->status == 0 && outpb->cnt == 0);
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if (outpb->status == 0)
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return ipb.buf[0] & 0xff;
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return -1;
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}
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