| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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/bootmem.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/pgtable.h> |
| 30 | #include <asm/sections.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 | */ |
| 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_kbd; |
| 68 | unsigned long uboot_initrd_start, uboot_initrd_end; |
| 69 | unsigned long uboot_cmd_start, uboot_cmd_end; |
| 70 | |
| 71 | sp = (unsigned long *)_init_sp; |
| 72 | uboot_kbd = sp[1]; |
| 73 | uboot_initrd_start = sp[2]; |
| 74 | uboot_initrd_end = sp[3]; |
| 75 | uboot_cmd_start = sp[4]; |
| 76 | uboot_cmd_end = sp[5]; |
| 77 | |
| 78 | if (uboot_cmd_start && uboot_cmd_end) |
| 79 | strncpy(commandp, (const char *)uboot_cmd_start, size); |
| 80 | #if defined(CONFIG_BLK_DEV_INITRD) |
| 81 | if (uboot_initrd_start && uboot_initrd_end && |
| 82 | (uboot_initrd_end > uboot_initrd_start)) { |
| 83 | initrd_start = uboot_initrd_start; |
| 84 | initrd_end = uboot_initrd_end; |
| 85 | ROOT_DEV = Root_RAM0; |
| 86 | pr_info("initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end); |
| 87 | } |
| 88 | #endif /* if defined(CONFIG_BLK_DEV_INITRD) */ |
| 89 | } |
| 90 | |
| 91 | __init void process_uboot_commandline(char *commandp, int size) |
| 92 | { |
| 93 | int len, n; |
| 94 | |
| 95 | n = strnlen(commandp, size); |
| 96 | commandp += n; |
| 97 | len = size - n; |
| 98 | if (len) { |
| 99 | /* Add the whitespace separator */ |
| 100 | *commandp++ = ' '; |
| 101 | len--; |
| 102 | } |
| 103 | |
| 104 | parse_uboot_commandline(commandp, len); |
| 105 | commandp[size - 1] = 0; |
| 106 | } |