arch/mips/sibyte/sb1250/prom.c

   1 /*
   2  * Copyright (C) 2000, 2001 Broadcom Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/blkdev.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/smp.h>
  26
  27 #include <asm/bootinfo.h>
  28 #include <asm/reboot.h>
  29
  30 #ifdef CONFIG_EMBEDDED_RAMDISK
  31 /* These are symbols defined by the ramdisk linker script */
  32 extern unsigned char __rd_start;
  33 extern unsigned char __rd_end;
  34 #endif
  35
  36 #define MAX_RAM_SIZE ((CONFIG_SIBYTE_STANDALONE_RAM_SIZE * 1024 * 1024) - 1)
  37
  38 static __init void prom_meminit(void)
  39 {
  40 #ifdef CONFIG_BLK_DEV_INITRD
  41         unsigned long initrd_pstart;
  42         unsigned long initrd_pend;
  43
  44 #ifdef CONFIG_EMBEDDED_RAMDISK
  45         /* If we're using an embedded ramdisk, then __rd_start and __rd_end
  46            are defined by the linker to be on either side of the ramdisk
  47            area.  Otherwise, initrd_start should be defined by kernel command
  48            line arguments */
  49         if (initrd_start == 0) {
  50                 initrd_start = (unsigned long)&__rd_start;
  51                 initrd_end = (unsigned long)&__rd_end;
  52         }
  53 #endif
  54
  55         initrd_pstart = __pa(initrd_start);
  56         initrd_pend = __pa(initrd_end);
  57         if (initrd_start &&
  58             ((initrd_pstart > MAX_RAM_SIZE)
  59              || (initrd_pend > MAX_RAM_SIZE))) {
  60                 panic("initrd out of addressable memory");
  61         }
  62
  63         add_memory_region(0, initrd_pstart,
  64                           BOOT_MEM_RAM);
  65         add_memory_region(initrd_pstart, initrd_pend - initrd_pstart,
  66                           BOOT_MEM_RESERVED);
  67         add_memory_region(initrd_pend,
  68                           (CONFIG_SIBYTE_STANDALONE_RAM_SIZE * 1024 * 1024) - initrd_pend,
  69                           BOOT_MEM_RAM);
  70 #else
  71         add_memory_region(0, CONFIG_SIBYTE_STANDALONE_RAM_SIZE * 1024 * 1024,
  72                           BOOT_MEM_RAM);
  73 #endif
  74 }
  75
  76 void prom_cpu0_exit(void *unused)
  77 {
  78         while (1) ;
  79 }
  80
  81 static void prom_linux_exit(void)
  82 {
  83 #ifdef CONFIG_SMP
  84         if (smp_processor_id()) {
  85                 smp_call_function(prom_cpu0_exit,NULL,1,1);
  86         }
  87 #endif
  88         while(1);
  89 }
  90
  91 /*
  92  * prom_init is called just after the cpu type is determined, from setup_arch()
  93  */
  94 void __init prom_init(void)
  95 {
  96         _machine_restart   = (void (*)(char *))prom_linux_exit;
  97         _machine_halt      = prom_linux_exit;
  98         _machine_power_off = prom_linux_exit;
  99
 100         strcpy(arcs_cmdline, "root=/dev/ram0 ");
 101
 102         mips_machgroup = MACH_GROUP_SIBYTE;
 103         prom_meminit();
 104 }
 105
 106 unsigned long __init prom_free_prom_memory(void)
 107 {
 108         /* Not sure what I'm supposed to do here.  Nothing, I think */
 109         return 0;
 110 }
 111
 112 void prom_putchar(char c)
 113 {
 114 }