release/src-rt-6.x.4708/linux/linux-2.6.36/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/system.h>
  30 #include <asm/cacheflush.h>
  31 #include <asm/traps.h>
  32
  33 #include <asm/mips-boards/prom.h>
  34 #include <asm/mips-boards/generic.h>
  35 #include <asm/mach-powertv/asic.h>
  36
  37 static int *_prom_envp;
  38 unsigned long _prom_memsize;
  39
  40 /*
  41  * YAMON (32-bit PROM) pass arguments and environment as 32-bit pointer.
  42  * This macro take care of sign extension, if running in 64-bit mode.
  43  */
  44 #define prom_envp(index) ((char *)(long)_prom_envp[(index)])
  45
  46 char *prom_getenv(char *envname)
  47 {
  48         char *result = NULL;
  49
  50         if (_prom_envp != NULL) {
  51                 /*
  52                  * Return a pointer to the given environment variable.
  53                  * In 64-bit mode: we're using 64-bit pointers, but all pointers
  54                  * in the PROM structures are only 32-bit, so we need some
  55                  * workarounds, if we are running in 64-bit mode.
  56                  */
  57                 int i, index = 0;
  58
  59                 i = strlen(envname);
  60
  61                 while (prom_envp(index)) {
  62                         if (strncmp(envname, prom_envp(index), i) == 0) {
  63                                 result = prom_envp(index + 1);
  64                                 break;
  65                         }
  66                         index += 2;
  67                 }
  68         }
  69
  70         return result;
  71 }
  72
  73 /* TODO: Verify on linux-mips mailing list that the following two  */
  74 /* functions are correct                                           */
  75 /* TODO: Copy NMI and EJTAG exception vectors to memory from the   */
  76 /* BootROM exception vectors. Flush their cache entries. test it.  */
  77
  78 static void __init mips_nmi_setup(void)
  79 {
  80         void *base;
  81 #if defined(CONFIG_CPU_MIPS32_R1)
  82         base = cpu_has_veic ?
  83                 (void *)(CAC_BASE + 0xa80) :
  84                 (void *)(CAC_BASE + 0x380);
  85 #elif defined(CONFIG_CPU_MIPS32_R2)
  86         base = (void *)0xbfc00000;
  87 #else
  88 #error NMI exception handler address not defined
  89 #endif
  90 }
  91
  92 static void __init mips_ejtag_setup(void)
  93 {
  94         void *base;
  95
  96 #if defined(CONFIG_CPU_MIPS32_R1)
  97         base = cpu_has_veic ?
  98                 (void *)(CAC_BASE + 0xa00) :
  99                 (void *)(CAC_BASE + 0x300);
 100 #elif defined(CONFIG_CPU_MIPS32_R2)
 101         base = (void *)0xbfc00480;
 102 #else
 103 #error EJTAG exception handler address not defined
 104 #endif
 105 }
 106
 107 void __init prom_init(void)
 108 {
 109         int prom_argc;
 110         char *prom_argv;
 111
 112         prom_argc = fw_arg0;
 113         prom_argv = (char *) fw_arg1;
 114         _prom_envp = (int *) fw_arg2;
 115         _prom_memsize = (unsigned long) fw_arg3;
 116
 117         board_nmi_handler_setup = mips_nmi_setup;
 118         board_ejtag_handler_setup = mips_ejtag_setup;
 119
 120         if (prom_argc == 1) {
 121                 strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
 122                 strlcat(arcs_cmdline, prom_argv, COMMAND_LINE_SIZE);
 123         }
 124
 125         configure_platform();
 126         prom_meminit();
 127
 128 #ifndef CONFIG_BOOTLOADER_DRIVER
 129         pr_info("\nBootloader driver isn't loaded...\n");
 130 #endif
 131 }