sim/ppc/hw_register.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19     */
  20
  21
  22 #ifndef _HW_REGISTER_C_
  23 #define _HW_REGISTER_C_
  24
  25 #include "device_table.h"
  26 #include <stdlib.h>
  27 #include "psim.h"
  28
  29 /* DEVICE
  30
  31    register - dummy device to initialize processor registers
  32
  33    DESCRIPTION
  34
  35    The properties of this device are used, during initialization, to
  36    specify the initial value of various processor registers.  The
  37    property name specifying the register to be initialized with the
  38    special form <cpu-nr>.<register> being used to initialize a
  39    specific processor's register (eg 0.pc).
  40
  41    Because, when the device tree is created, overriding properties are
  42    entered into the tree before any default values, this device must
  43    initialize registers in newest (default) to oldest (overriding)
  44    property order.
  45
  46    The actual registers (for a given target) are defined in the file
  47    registers.c.
  48
  49    This device is normally a child of the /openprom/init node.
  50
  51    EXAMPLE
  52
  53    Given a device tree containing the entry:
  54
  55    |    /openprom/init/register/pc 0xfff00cf0
  56
  57    then specifying the command line option:
  58
  59    |    -o '/openprom/init/register/pc 0x0'
  60
  61    would override the initial value of processor zero's program
  62    counter.  The resultant device tree tree containing:
  63
  64    |    /openprom/init/register/0.pc 0x0
  65    |    /openprom/init/register/pc 0xfff00cf0
  66
  67    and would be processed last to first resulting in the sequence: set
  68    all program counters to 0xfff00cf0; set processor zero's program
  69    counter to zero. */
  70
  71 static void
  72 do_register_init(device *me,
  73                  const device_property *prop)
  74 {
  75   psim *system = device_system(me);
  76   if (prop != NULL) {
  77     const char *name = prop->name;
  78     unsigned32 value = device_find_integer_property(me, name);
  79     int processor;
  80
  81     do_register_init(me, device_next_property(prop));
  82
  83     if (strchr(name, '.') == NULL) {
  84       processor = -1;
  85       DTRACE(register, ("%s=0x%lx\n", name, (unsigned long)value));
  86     }
  87     else {
  88       char *end;
  89       processor = strtoul(name, &end, 0);
  90       ASSERT(end[0] == '.');
  91       name = end+1;
  92       DTRACE(register, ("%d.%s=0x%lx\n", processor, name,
  93                         (unsigned long)value));
  94     }
  95     psim_write_register(system, processor, /* all processors */
  96                         &value,
  97                         name,
  98                         cooked_transfer);
  99   }
 100 }
 101
 102
 103 static void
 104 register_init_data_callback(device *me)
 105 {
 106   const device_property *prop = device_find_property(me, NULL);
 107   do_register_init(me, prop);
 108 }
 109
 110
 111 static device_callbacks const register_callbacks = {
 112   { NULL, register_init_data_callback, },
 113   { NULL, }, /* address */
 114   { NULL, }, /* IO */
 115   { NULL, }, /* DMA */
 116   { NULL, }, /* interrupt */
 117   { NULL, }, /* unit */
 118 };
 119
 120 const device_descriptor hw_register_device_descriptor[] = {
 121   { "register", NULL, &register_callbacks },
 122   { NULL },
 123 };
 124
 125 #endif _HW_REGISTER_C_