arch/mips/powertv/init.c

   1 /*
   2  * Copyright (C) 1999, 2000, 2004, 2005  MIPS Technologies, Inc.
   3  *      All rights reserved.
   4  *      Authors: Carsten Langgaard <carstenl@mips.com>
   5  *               Maciej W. Rozycki <macro@mips.com>
   6  * Portions copyright (C) 2009 Cisco Systems, Inc.
   7  *
   8  *  This program is free software; you can distribute it and/or modify it
   9  *  under the terms of the GNU General Public License (Version 2) as
  10  *  published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope it will be useful, but WITHOUT
  13  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  *  for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License along
  18  *  with this program; if not, write to the Free Software Foundation, Inc.,
  19  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  20  *
  21  * PROM library initialisation code.
  22  */
  23 #include <linux/init.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26
  27 #include <asm/bootinfo.h>
  28 #include <linux/io.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/traps.h>
  31
  32 #include <asm/mips-boards/prom.h>
  33 #include <asm/mips-boards/generic.h>
  34 #include <asm/mach-powertv/asic.h>
  35
  36 static int *_prom_envp;
  37 unsigned long _prom_memsize;
  38
  39 /*
  40  * YAMON (32-bit PROM) pass arguments and environment as 32-bit pointer.
  41  * This macro take care of sign extension, if running in 64-bit mode.
  42  */
  43 #define prom_envp(index) ((char *)(long)_prom_envp[(index)])
  44
  45 char *prom_getenv(char *envname)
  46 {
  47         char *result = NULL;
  48
  49         if (_prom_envp != NULL) {
  50                 /*
  51                  * Return a pointer to the given environment variable.
  52                  * In 64-bit mode: we're using 64-bit pointers, but all pointers
  53                  * in the PROM structures are only 32-bit, so we need some
  54                  * workarounds, if we are running in 64-bit mode.
  55                  */
  56                 int i, index = 0;
  57
  58                 i = strlen(envname);
  59
  60                 while (prom_envp(index)) {
  61                         if (strncmp(envname, prom_envp(index), i) == 0) {
  62                                 result = prom_envp(index + 1);
  63                                 break;
  64                         }
  65                         index += 2;
  66                 }
  67         }
  68
  69         return result;
  70 }
  71
  72 void __init prom_init(void)
  73 {
  74         int prom_argc;
  75         char *prom_argv;
  76
  77         prom_argc = fw_arg0;
  78         prom_argv = (char *) fw_arg1;
  79         _prom_envp = (int *) fw_arg2;
  80         _prom_memsize = (unsigned long) fw_arg3;
  81
  82         if (prom_argc == 1) {
  83                 strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
  84                 strlcat(arcs_cmdline, prom_argv, COMMAND_LINE_SIZE);
  85         }
  86
  87         configure_platform();
  88         prom_meminit();
  89
  90 #ifndef CONFIG_BOOTLOADER_DRIVER
  91         pr_info("\nBootloader driver isn't loaded...\n");
  92 #endif
  93 }