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prom.c revision 1.10.22.1 
      1 /* $NetBSD: prom.c,v 1.10.22.1 2002/09/06 08:31:36 jdolecek Exp $ */
      2 
      3 /*
      4  * Mach Operating System
      5  * Copyright (c) 1992 Carnegie Mellon University
      6  * All Rights Reserved.
      7  *
      8  * Permission to use, copy, modify and distribute this software and its
      9  * documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
     16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie Mellon
     26  * the rights to redistribute these changes.
     27  */
     28 
     29 #include <lib/libkern/libkern.h>
     30 
     31 #include <sys/types.h>
     32 
     33 #include <machine/prom.h>
     34 #include <machine/rpb.h>
     35 
     36 #include "common.h"
     37 
     38 int console;
     39 
     40 #if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
     41 static int test_getchar(int *);
     42 #endif
     43 static void putonechar(int c);
     44 
     45 void
     46 init_prom_calls()
     47 {
     48 	extern struct prom_vec prom_dispatch_v;
     49 	struct rpb *r;
     50 	struct crb *c;
     51 	char buf[4];
     52 
     53 	r = (struct rpb *)HWRPB_ADDR;
     54 	c = (struct crb *)((u_int8_t *)r + r->rpb_crb_off);
     55 
     56 	prom_dispatch_v.routine_arg = c->crb_v_dispatch;
     57 	prom_dispatch_v.routine = c->crb_v_dispatch->entry_va;
     58 
     59 	/* Look for console tty. */
     60 	prom_getenv(PROM_E_TTY_DEV, buf, 4);
     61 	console = buf[0] - '0';
     62 }
     63 
     64 #if !defined(NO_GETCHAR) || !defined(NO_PUTCHAR_HALT)
     65 static int
     66 test_getchar(xc)
     67 	int *xc;
     68 {
     69 	prom_return_t ret;
     70 
     71 	ret.bits = prom_dispatch(PROM_R_GETC, console);
     72 	*xc = ret.u.retval;
     73 	return ret.u.status == 0 || ret.u.status == 1;
     74 }
     75 #endif
     76 
     77 #if !defined(NO_GETCHAR)
     78 int
     79 getchar()
     80 {
     81 	int c;
     82 
     83 	for (;;) {
     84 		if (test_getchar(&c)) {
     85 			if (c == 3)
     86 				halt();
     87 			return c;
     88 		}
     89 	}
     90 }
     91 #endif
     92 
     93 static void
     94 putonechar(c)
     95 	int c;
     96 {
     97 	prom_return_t ret;
     98 	char cbuf = c;
     99 
    100 	do {
    101 		ret.bits = prom_dispatch(PROM_R_PUTS, console, &cbuf, 1);
    102 	} while ((ret.u.retval & 1) == 0);
    103 }
    104 
    105 void
    106 putchar(c)
    107 	int c;
    108 {
    109 #if !defined(NO_PUTCHAR_HALT)
    110 	int typed_c;
    111 #endif
    112 
    113 	if (c == '\r' || c == '\n') {
    114 		putonechar('\r');
    115 		c = '\n';
    116 	}
    117 	putonechar(c);
    118 #if !defined(NO_PUTCHAR_HALT)
    119 	if (test_getchar(&typed_c))
    120 		if (typed_c == 3)
    121 			halt();
    122 #endif
    123 }
    124 
    125 int
    126 prom_getenv(id, buf, len)
    127 	int id, len;
    128 	char *buf;
    129 {
    130 	/*
    131 	 * On at least some systems, the GETENV call requires a
    132 	 * 8-byte-aligned buffer, or it bails out with a "kernel stack
    133 	 * not valid halt". Provide a local, aligned buffer here and
    134 	 * then copy to the caller's buffer.
    135 	 */
    136 	static char abuf[128] __attribute__((aligned (8)));
    137 	prom_return_t ret;
    138 
    139 	ret.bits = prom_dispatch(PROM_R_GETENV, id, abuf, 128);
    140 	if (ret.u.status & 0x4)
    141 		ret.u.retval = 0;
    142 	len = min(len - 1, ret.u.retval);
    143 	memcpy(buf, abuf, len);
    144 	buf[len] = '\0';
    145 
    146 	return (len);
    147 }
    148