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 */ 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 strscpy(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 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