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Diffstat (limited to 'libgloss/rs6000/mbx-inbyte.c')
-rw-r--r-- | libgloss/rs6000/mbx-inbyte.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/libgloss/rs6000/mbx-inbyte.c b/libgloss/rs6000/mbx-inbyte.c new file mode 100644 index 000000000..bd06aa04d --- /dev/null +++ b/libgloss/rs6000/mbx-inbyte.c @@ -0,0 +1,60 @@ +/* + * mbx-inbyte.c -- inbyte function for targets using the eppcbug monitor + * + * Copyright (c) 1998 Cygnus Support + * + * The authors hereby grant permission to use, copy, modify, distribute, + * and license this software and its documentation for any purpose, provided + * that existing copyright notices are retained in all copies and that this + * notice is included verbatim in any distributions. No written agreement, + * license, or royalty fee is required for any of the authorized uses. + * Modifications to this software may be copyrighted by their authors + * and need not follow the licensing terms described here, provided that + * the new terms are clearly indicated on the first page of each file where + * they apply. + */ + +#include "ppc-asm.h" + +int inbyte(void) +{ + struct { + unsigned clun; + unsigned dlun; + char *data; + unsigned len; + unsigned rsrvd; + char buf[4]; + } ipb, *inpb; + + struct { + int status; + int cnt; + } opb, *outpb; + + inpb = &ipb; + outpb = &opb; + + do { + inpb->clun = 0; + inpb->dlun = 0; + inpb->data = ipb.buf; + inpb->len = 1; + inpb->rsrvd = 0; + + asm volatile ( + "mr 3,%0\n" + "mr 4,%1\n" + "li 10,0x200\n" + "sc" + : /* no outputs */ + : "r" (inpb), "r" (outpb) + : "3", "4", "10" + ); + } while (outpb->status == 0 && outpb->cnt == 0); + + if (outpb->status == 0) + return ipb.buf[0] & 0xff; + + return -1; +} |