sys/arch/alpha/stand/common/prom.c

   1 /* $NetBSD: prom.c,v 1.13 2009/03/14 21:04:03 dsl 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@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(void)
  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(int *xc)
  67 {
  68         prom_return_t ret;
  69
  70         ret.bits = prom_dispatch(PROM_R_GETC, console);
  71         *xc = ret.u.retval;
  72         return ret.u.status == 0 || ret.u.status == 1;
  73 }
  74 #endif
  75
  76 #if !defined(NO_GETCHAR)
  77 int
  78 getchar(void)
  79 {
  80         int c;
  81
  82         for (;;) {
  83                 if (test_getchar(&c)) {
  84                         if (c == 3)
  85                                 halt();
  86                         return c;
  87                 }
  88         }
  89 }
  90 #endif
  91
  92 static void
  93 putonechar(int c)
  94 {
  95         prom_return_t ret;
  96         char cbuf = c;
  97
  98         do {
  99                 ret.bits = prom_dispatch(PROM_R_PUTS, console, &cbuf, 1);
 100         } while ((ret.u.retval & 1) == 0);
 101 }
 102
 103 void
 104 putchar(int c)
 105 {
 106 #if !defined(NO_PUTCHAR_HALT)
 107         int typed_c;
 108 #endif
 109
 110         if (c == '\r' || c == '\n') {
 111                 putonechar('\r');
 112                 c = '\n';
 113         }
 114         putonechar(c);
 115 #if !defined(NO_PUTCHAR_HALT)
 116         if (test_getchar(&typed_c))
 117                 if (typed_c == 3)
 118                         halt();
 119 #endif
 120 }
 121
 122 int
 123 prom_getenv(int id, char *buf, int len)
 124 {
 125         /*
 126          * On at least some systems, the GETENV call requires a
 127          * 8-byte-aligned buffer, or it bails out with a "kernel stack
 128          * not valid halt". Provide a local, aligned buffer here and
 129          * then copy to the caller's buffer.
 130          */
 131         static char abuf[128] __attribute__((aligned (8)));
 132         prom_return_t ret;
 133
 134         ret.bits = prom_dispatch(PROM_R_GETENV, id, abuf, 128);
 135         if (ret.u.status & 0x4)
 136                 ret.u.retval = 0;
 137         len = min(len - 1, ret.u.retval);
 138         memcpy(buf, abuf, len);
 139         buf[len] = '\0';
 140
 141         return (len);
 142 }