sim/ppc/hw_register.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright 1994, 1995, 1996, 2003 Andrew Cagney
   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 3 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, see <http://www.gnu.org/licenses/>.
  17
  18     */
  19
  20
  21 #ifndef _HW_REGISTER_C_
  22 #define _HW_REGISTER_C_
  23
  24 #include "device_table.h"
  25 #include <stdlib.h>
  26 #include "psim.h"
  27
  28 /* DEVICE
  29
  30
  31    register - dummy device to initialize processor registers
  32
  33
  34    DESCRIPTION
  35
  36    The properties of this device are used, during initialization, to
  37    specify the initial value of various processor registers.  The
  38    property name specifying the register to be initialized with the
  39    special form <cpu-nr>.<register> being used to initialize a
  40    specific processor's register (eg 0.pc).
  41
  42    Because, when the device tree is created, overriding properties are
  43    entered into the tree before any default values, this device must
  44    initialize registers in newest (default) to oldest (overriding)
  45    property order.
  46
  47    The actual registers (for a given target) are defined in the file
  48    registers.c.
  49
  50    This device is normally a child of the /openprom/init node.
  51
  52
  53    EXAMPLES
  54
  55
  56    Given a device tree containing the entry:
  57
  58    |    /openprom/init/register/pc 0xfff00cf0
  59
  60    then specifying the command line option:
  61
  62    |    -o '/openprom/init/register/pc 0x0'
  63
  64    would override the initial value of processor zero's program
  65    counter.  The resultant device tree tree containing:
  66
  67    |    /openprom/init/register/0.pc 0x0
  68    |    /openprom/init/register/pc 0xfff00cf0
  69
  70    and would be processed last to first resulting in the sequence: set
  71    all program counters to 0xfff00cf0; set processor zero's program
  72    counter to zero.
  73
  74    */
  75
  76 static void
  77 do_register_init(device *me,
  78                  const device_property *prop)
  79 {
  80   psim *system = device_system(me);
  81   if (prop != NULL) {
  82     const char *name = prop->name;
  83     unsigned32 value = device_find_integer_property(me, name);
  84     int processor;
  85
  86     do_register_init(me, device_next_property(prop));
  87
  88     if (strchr(name, '.') == NULL) {
  89       processor = -1;
  90       DTRACE(register, ("%s=0x%lx\n", name, (unsigned long)value));
  91     }
  92     else {
  93       char *end;
  94       processor = strtoul(name, &end, 0);
  95       ASSERT(end[0] == '.');
  96       name = end+1;
  97       DTRACE(register, ("%d.%s=0x%lx\n", processor, name,
  98                         (unsigned long)value));
  99     }
 100     if (psim_write_register(system, processor, /* all processors */
 101                             &value,
 102                             name,
 103                             cooked_transfer) <= 0)
 104       error("Invalid register name %s\n", name);
 105   }
 106 }
 107
 108
 109 static void
 110 register_init_data_callback(device *me)
 111 {
 112   const device_property *prop = device_find_property(me, NULL);
 113   do_register_init(me, prop);
 114 }
 115
 116
 117 static device_callbacks const register_callbacks = {
 118   { NULL, register_init_data_callback, },
 119   { NULL, }, /* address */
 120   { NULL, }, /* IO */
 121   { NULL, }, /* DMA */
 122   { NULL, }, /* interrupt */
 123   { NULL, }, /* unit */
 124 };
 125
 126 const device_descriptor hw_register_device_descriptor[] = {
 127   { "register", NULL, &register_callbacks },
 128   { NULL },
 129 };
 130
 131 #endif /* _HW_REGISTER_C_ */