| Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Startup code for use with the u-boot bootloader. |
| 3 | * |
| 4 | * Copyright (C) 2004-2006 Atmel Corporation |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | #include <asm/setup.h> |
| 11 | |
| 12 | /* |
| 13 | * The kernel is loaded where we want it to be and all caches |
| 14 | * have just been flushed. We get two parameters from u-boot: |
| 15 | * |
| 16 | * r12 contains a magic number (ATAG_MAGIC) |
| 17 | * r11 points to a tag table providing information about |
| 18 | * the system. |
| 19 | */ |
| 20 | .section .init.text,"ax" |
| 21 | .global _start |
| 22 | _start: |
| 23 | /* Check if the boot loader actually provided a tag table */ |
| 24 | lddpc r0, magic_number |
| 25 | cp.w r12, r0 |
| 26 | brne no_tag_table |
| 27 | |
| 28 | /* Initialize .bss */ |
| 29 | lddpc r2, bss_start_addr |
| 30 | lddpc r3, end_addr |
| 31 | mov r0, 0 |
| 32 | mov r1, 0 |
| 33 | 1: st.d r2++, r0 |
| 34 | cp r2, r3 |
| 35 | brlo 1b |
| 36 | |
| 37 | /* |
| 38 | * Save the tag table address for later use. This must be done |
| 39 | * _after_ .bss has been initialized... |
| 40 | */ |
| 41 | lddpc r0, tag_table_addr |
| 42 | st.w r0[0], r11 |
| 43 | |
| 44 | /* Jump to loader-independent setup code */ |
| 45 | rjmp kernel_entry |
| 46 | |
| 47 | .align 2 |
| 48 | magic_number: |
| 49 | .long ATAG_MAGIC |
| 50 | tag_table_addr: |
| 51 | .long bootloader_tags |
| 52 | bss_start_addr: |
| 53 | .long __bss_start |
| 54 | end_addr: |
| 55 | .long _end |
| 56 | |
| 57 | no_tag_table: |
| 58 | sub r12, pc, (. - 2f) |
| 59 | bral panic |
| 60 | 2: .asciz "Boot loader didn't provide correct magic number\n" |