LXR linux/arch/m68k/kernel/uboot.c

   1/*
   2 * uboot.c -- uboot arguments support
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file COPYING in the main directory of this archive
   6 * for more details.
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/sched.h>
  11#include <linux/delay.h>
  12#include <linux/interrupt.h>
  13#include <linux/fb.h>
  14#include <linux/module.h>
  15#include <linux/mm.h>
  16#include <linux/console.h>
  17#include <linux/errno.h>
  18#include <linux/string.h>
  19#include <linux/bootmem.h>
  20#include <linux/seq_file.h>
  21#include <linux/init.h>
  22#include <linux/initrd.h>
  23#include <linux/root_dev.h>
  24#include <linux/rtc.h>
  25
  26#include <asm/setup.h>
  27#include <asm/irq.h>
  28#include <asm/machdep.h>
  29#include <asm/pgtable.h>
  30#include <asm/sections.h>
  31
  32/*
  33 * parse_uboot_commandline
  34 *
  35 * Copies u-boot commandline arguments and store them in the proper linux
  36 * variables.
  37 *
  38 * Assumes:
  39 *      _init_sp global contains the address in the stack pointer when the
  40 *      kernel starts (see head.S::_start)
  41 *
  42 *      U-Boot calling convention:
  43 *      (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
  44 *
  45 *      _init_sp can be parsed as such
  46 *
  47 *      _init_sp+00 = u-boot cmd after jsr into kernel (skip)
  48 *      _init_sp+04 = &kernel board_info (residual data)
  49 *      _init_sp+08 = &initrd_start
  50 *      _init_sp+12 = &initrd_end
  51 *      _init_sp+16 = &cmd_start
  52 *      _init_sp+20 = &cmd_end
  53 *
  54 *      This also assumes that the memory locations pointed to are still
  55 *      unmodified. U-boot places them near the end of external SDRAM.
  56 *
  57 * Argument(s):
  58 *      commandp = the linux commandline arg container to fill.
  59 *      size     = the sizeof commandp.
  60 *
  61 * Returns:
  62 */
  63static void __init parse_uboot_commandline(char *commandp, int size)
  64{
  65        extern unsigned long _init_sp;
  66        unsigned long *sp;
  67        unsigned long uboot_kbd;
  68        unsigned long uboot_initrd_start, uboot_initrd_end;
  69        unsigned long uboot_cmd_start, uboot_cmd_end;
  70
  71        sp = (unsigned long *)_init_sp;
  72        uboot_kbd = sp[1];
  73        uboot_initrd_start = sp[2];
  74        uboot_initrd_end = sp[3];
  75        uboot_cmd_start = sp[4];
  76        uboot_cmd_end = sp[5];
  77
  78        if (uboot_cmd_start && uboot_cmd_end)
  79                strncpy(commandp, (const char *)uboot_cmd_start, size);
  80#if defined(CONFIG_BLK_DEV_INITRD)
  81        if (uboot_initrd_start && uboot_initrd_end &&
  82            (uboot_initrd_end > uboot_initrd_start)) {
  83                initrd_start = uboot_initrd_start;
  84                initrd_end = uboot_initrd_end;
  85                ROOT_DEV = Root_RAM0;
  86                pr_info("initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
  87        }
  88#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
  89}
  90
  91__init void process_uboot_commandline(char *commandp, int size)
  92{
  93        int len, n;
  94
  95        n = strnlen(commandp, size);
  96        commandp += n;
  97        len = size - n;
  98        if (len) {
  99                /* Add the whitespace separator */
 100                *commandp++ = ' ';
 101                len--;
 102        }
 103
 104        parse_uboot_commandline(commandp, len);
 105        commandp[size - 1] = 0;
 106}
 107