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/memblock.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/sections.h>
30#include <asm/bootinfo.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_cmd_start, uboot_cmd_end;
68#if defined(CONFIG_BLK_DEV_INITRD)
69	unsigned long uboot_initrd_start, uboot_initrd_end;
70#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
71
72	sp = (unsigned long *)_init_sp;
73	uboot_cmd_start = sp[4];
74	uboot_cmd_end = sp[5];
75
76	if (uboot_cmd_start && uboot_cmd_end)
77		strncpy(commandp, (const char *)uboot_cmd_start, size);
78
79#if defined(CONFIG_BLK_DEV_INITRD)
80	uboot_initrd_start = sp[2];
81	uboot_initrd_end = sp[3];
82
83	if (uboot_initrd_start && uboot_initrd_end &&
84	    (uboot_initrd_end > uboot_initrd_start)) {
85		initrd_start = uboot_initrd_start;
86		initrd_end = uboot_initrd_end;
87		ROOT_DEV = Root_RAM0;
88		pr_info("initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
89	}
90#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
91}
92
93__init void process_uboot_commandline(char *commandp, int size)
94{
95	int len, n;
96
97	n = strnlen(commandp, size);
98	commandp += n;
99	len = size - n;
100	if (len) {
101		/* Add the whitespace separator */
102		*commandp++ = ' ';
103		len--;
104	}
105
106	parse_uboot_commandline(commandp, len);
107	commandp[len - 1] = 0;
108}
109