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 */
parse_uboot_commandline(char * commandp,int size)63 static 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
process_uboot_commandline(char * commandp,int size)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