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