lib_m68k/bootm.c

   1 /*
   2  * (C) Copyright 2003
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  */
  23
  24 #include <common.h>
  25 #include <command.h>
  26 #include <image.h>
  27 #include <zlib.h>
  28 #include <bzlib.h>
  29 #include <watchdog.h>
  30 #include <environment.h>
  31 #include <asm/byteorder.h>
  32 #ifdef CONFIG_SHOW_BOOT_PROGRESS
  33 # include <status_led.h>
  34 #endif
  35
  36 DECLARE_GLOBAL_DATA_PTR;
  37
  38 #define PHYSADDR(x) x
  39
  40 #define LINUX_MAX_ENVS          256
  41 #define LINUX_MAX_ARGS          256
  42
  43 static ulong get_sp (void);
  44 static void set_clocks_in_mhz (bd_t *kbd);
  45
  46 int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
  47 {
  48         ulong sp;
  49
  50         ulong rd_len;
  51         ulong initrd_start, initrd_end;
  52         int ret;
  53
  54         ulong cmd_start, cmd_end;
  55         ulong bootmap_base;
  56         bd_t  *kbd;
  57         void  (*kernel) (bd_t *, ulong, ulong, ulong, ulong);
  58         struct lmb *lmb = &images->lmb;
  59
  60         bootmap_base = getenv_bootm_low();
  61
  62         /*
  63          * Booting a (Linux) kernel image
  64          *
  65          * Allocate space for command line and board info - the
  66          * address should be as high as possible within the reach of
  67          * the kernel (see CONFIG_SYS_BOOTMAPSZ settings), but in unused
  68          * memory, which means far enough below the current stack
  69          * pointer.
  70          */
  71         sp = get_sp();
  72         debug ("## Current stack ends at 0x%08lx ", sp);
  73
  74         /* adjust sp by 1K to be safe */
  75         sp -= 1024;
  76         lmb_reserve(lmb, sp, (CONFIG_SYS_SDRAM_BASE + gd->ram_size - sp));
  77
  78         /* allocate space and init command line */
  79         ret = boot_get_cmdline (lmb, &cmd_start, &cmd_end, bootmap_base);
  80         if (ret) {
  81                 puts("ERROR with allocation of cmdline\n");
  82                 goto error;
  83         }
  84
  85         /* allocate space for kernel copy of board info */
  86         ret = boot_get_kbd (lmb, &kbd, bootmap_base);
  87         if (ret) {
  88                 puts("ERROR with allocation of kernel bd\n");
  89                 goto error;
  90         }
  91         set_clocks_in_mhz(kbd);
  92
  93         kernel = (void (*)(bd_t *, ulong, ulong, ulong, ulong))images->ep;
  94
  95         rd_len = images->rd_end - images->rd_start;
  96         ret = boot_ramdisk_high (lmb, images->rd_start, rd_len,
  97                         &initrd_start, &initrd_end);
  98         if (ret)
  99                 goto error;
 100
 101         debug("## Transferring control to Linux (at address %08lx) ...\n",
 102               (ulong) kernel);
 103
 104         show_boot_progress (15);
 105
 106         /*
 107          * Linux Kernel Parameters (passing board info data):
 108          *   r3: ptr to board info data
 109          *   r4: initrd_start or 0 if no initrd
 110          *   r5: initrd_end - unused if r4 is 0
 111          *   r6: Start of command line string
 112          *   r7: End   of command line string
 113          */
 114         (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
 115         /* does not return */
 116 error:
 117         return 1;
 118 }
 119
 120 static ulong get_sp (void)
 121 {
 122         ulong sp;
 123
 124         asm("movel %%a7, %%d0\n"
 125             "movel %%d0, %0\n": "=d"(sp): :"%d0");
 126
 127         return sp;
 128 }
 129
 130 static void set_clocks_in_mhz (bd_t *kbd)
 131 {
 132         char *s;
 133
 134         if ((s = getenv("clocks_in_mhz")) != NULL) {
 135                 /* convert all clock information to MHz */
 136                 kbd->bi_intfreq /= 1000000L;
 137                 kbd->bi_busfreq /= 1000000L;
 138         }
 139 }