uboot.c
/*
* uboot.c -- uboot arguments support
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/memblock.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/root_dev.h>
#include <linux/rtc.h>
#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
/*
* parse_uboot_commandline
*
* Copies u-boot commandline arguments and store them in the proper linux
* variables.
*
* Assumes:
* _init_sp global contains the address in the stack pointer when the
* kernel starts (see head.S::_start)
*
* U-Boot calling convention:
* (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
*
* _init_sp can be parsed as such
*
* _init_sp+00 = u-boot cmd after jsr into kernel (skip)
* _init_sp+04 = &kernel board_info (residual data)
* _init_sp+08 = &initrd_start
* _init_sp+12 = &initrd_end
* _init_sp+16 = &cmd_start
* _init_sp+20 = &cmd_end
*
* This also assumes that the memory locations pointed to are still
* unmodified. U-boot places them near the end of external SDRAM.
*
* Argument(s):
* commandp = the linux commandline arg container to fill.
* size = the sizeof commandp.
*
* Returns:
*/
static void __init parse_uboot_commandline(char *commandp, int size)
{
extern unsigned long _init_sp;
unsigned long *sp;
unsigned long uboot_kbd;
unsigned long uboot_initrd_start, uboot_initrd_end;
unsigned long uboot_cmd_start, uboot_cmd_end;
sp = (unsigned long *)_init_sp;
uboot_kbd = sp[1];
uboot_initrd_start = sp[2];
uboot_initrd_end = sp[3];
uboot_cmd_start = sp[4];
uboot_cmd_end = sp[5];
if (uboot_cmd_start && uboot_cmd_end)
strncpy(commandp, (const char *)uboot_cmd_start, size);
#if defined(CONFIG_BLK_DEV_INITRD)
if (uboot_initrd_start && uboot_initrd_end &&
(uboot_initrd_end > uboot_initrd_start)) {
initrd_start = uboot_initrd_start;
initrd_end = uboot_initrd_end;
ROOT_DEV = Root_RAM0;
pr_info("initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
}
#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
}
__init void process_uboot_commandline(char *commandp, int size)
{
int len, n;
n = strnlen(commandp, size);
commandp += n;
len = size - n;
if (len) {
/* Add the whitespace separator */
*commandp++ = ' ';
len--;
}
parse_uboot_commandline(commandp, len);
commandp[len - 1] = 0;
}