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/module.h>
14 #include <linux/mm.h>
15 #include <linux/console.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/memblock.h>
19 #include <linux/seq_file.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/root_dev.h>
23 #include <linux/rtc.h>
24
25 #include <asm/setup.h>
26 #include <asm/irq.h>
27 #include <asm/machdep.h>
28 #include <asm/sections.h>
29 #include <asm/bootinfo.h>
30
31 /*
32 * parse_uboot_commandline
33 *
34 * Copies u-boot commandline arguments and store them in the proper linux
35 * variables.
36 *
37 * Assumes:
38 * _init_sp global contains the address in the stack pointer when the
39 * kernel starts (see head.S::_start)
40 *
41 * U-Boot calling convention:
42 * (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
43 *
44 * _init_sp can be parsed as such
45 *
46 * _init_sp+00 = u-boot cmd after jsr into kernel (skip)
47 * _init_sp+04 = &kernel board_info (residual data)
48 * _init_sp+08 = &initrd_start
49 * _init_sp+12 = &initrd_end
50 * _init_sp+16 = &cmd_start
51 * _init_sp+20 = &cmd_end
52 *
53 * This also assumes that the memory locations pointed to are still
54 * unmodified. U-boot places them near the end of external SDRAM.
55 *
56 * Argument(s):
57 * commandp = the linux commandline arg container to fill.
58 * size = the sizeof commandp.
59 *
60 * Returns:
61 */
parse_uboot_commandline(char * commandp,int size)62 static void __init parse_uboot_commandline(char *commandp, int size)
63 {
64 extern unsigned long _init_sp;
65 unsigned long *sp;
66 unsigned long uboot_cmd_start, uboot_cmd_end;
67 #if defined(CONFIG_BLK_DEV_INITRD)
68 unsigned long uboot_initrd_start, uboot_initrd_end;
69 #endif /* if defined(CONFIG_BLK_DEV_INITRD) */
70
71 sp = (unsigned long *)_init_sp;
72 uboot_cmd_start = sp[4];
73 uboot_cmd_end = sp[5];
74
75 if (uboot_cmd_start && uboot_cmd_end)
76 strncpy(commandp, (const char *)uboot_cmd_start, size);
77
78 #if defined(CONFIG_BLK_DEV_INITRD)
79 uboot_initrd_start = sp[2];
80 uboot_initrd_end = sp[3];
81
82 if (uboot_initrd_start && uboot_initrd_end &&
83 (uboot_initrd_end > uboot_initrd_start)) {
84 initrd_start = uboot_initrd_start;
85 initrd_end = uboot_initrd_end;
86 ROOT_DEV = Root_RAM0;
87 pr_info("initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
88 }
89 #endif /* if defined(CONFIG_BLK_DEV_INITRD) */
90 }
91
process_uboot_commandline(char * commandp,int size)92 __init void process_uboot_commandline(char *commandp, int size)
93 {
94 int len, n;
95
96 n = strnlen(commandp, size);
97 commandp += n;
98 len = size - n;
99 if (len) {
100 /* Add the whitespace separator */
101 *commandp++ = ' ';
102 len--;
103 }
104
105 parse_uboot_commandline(commandp, len);
106 commandp[len - 1] = 0;
107 }
108