| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* $Id: head.S,v 1.7 2003/09/01 17:58:19 lethal Exp $ |
| 2 | * |
| 3 | * arch/sh/kernel/head.S |
| 4 | * |
| 5 | * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima |
| 6 | * |
| 7 | * This file is subject to the terms and conditions of the GNU General Public |
| 8 | * License. See the file "COPYING" in the main directory of this archive |
| 9 | * for more details. |
| 10 | * |
| 11 | * Head.S contains the SH exception handlers and startup code. |
| 12 | */ |
| 13 | #include <linux/linkage.h> |
| 14 | |
| 15 | .section .empty_zero_page, "aw" |
| 16 | ENTRY(empty_zero_page) |
| 17 | .long 1 /* MOUNT_ROOT_RDONLY */ |
| 18 | .long 0 /* RAMDISK_FLAGS */ |
| 19 | .long 0x0200 /* ORIG_ROOT_DEV */ |
| 20 | .long 1 /* LOADER_TYPE */ |
| 21 | .long 0x00360000 /* INITRD_START */ |
| 22 | .long 0x000a0000 /* INITRD_SIZE */ |
| 23 | .long 0 |
| 24 | .balign 4096,0,4096 |
| 25 | |
| 26 | .text |
| 27 | /* |
| 28 | * Condition at the entry of _stext: |
| 29 | * |
| 30 | * BSC has already been initialized. |
| 31 | * INTC may or may not be initialized. |
| 32 | * VBR may or may not be initialized. |
| 33 | * MMU may or may not be initialized. |
| 34 | * Cache may or may not be initialized. |
| 35 | * Hardware (including on-chip modules) may or may not be initialized. |
| 36 | * |
| 37 | */ |
| 38 | ENTRY(_stext) |
| 39 | ! Initialize Status Register |
| 40 | mov.l 1f, r0 ! MD=1, RB=0, BL=0, IMASK=0xF |
| 41 | ldc r0, sr |
| 42 | ! Initialize global interrupt mask |
| 43 | mov #0, r0 |
| 44 | ldc r0, r6_bank |
| 45 | ! |
| 46 | mov.l 2f, r0 |
| 47 | mov r0, r15 ! Set initial r15 (stack pointer) |
| 48 | mov #0x20, r1 ! |
| 49 | shll8 r1 ! r1 = 8192 |
| 50 | sub r1, r0 ! |
| 51 | ldc r0, r7_bank ! ... and initial thread_info |
| 52 | ! |
| 53 | ! Additional CPU initialization |
| 54 | mov.l 6f, r0 |
| 55 | jsr @r0 |
| 56 | nop |
| 57 | ! Clear BSS area |
| 58 | mov.l 3f, r1 |
| 59 | add #4, r1 |
| 60 | mov.l 4f, r2 |
| 61 | mov #0, r0 |
| 62 | 9: cmp/hs r2, r1 |
| 63 | bf/s 9b ! while (r1 < r2) |
| 64 | mov.l r0,@-r2 |
| 65 | ! Start kernel |
| 66 | mov.l 5f, r0 |
| 67 | jmp @r0 |
| 68 | nop |
| 69 | |
| 70 | .balign 4 |
| 71 | 1: .long 0x400080F0 ! MD=1, RB=0, BL=0, FD=1, IMASK=0xF |
| 72 | 2: .long stack |
| 73 | 3: .long __bss_start |
| 74 | 4: .long _end |
| 75 | 5: .long start_kernel |
| 76 | 6: .long sh_cpu_init |