/* $Id: head.S,v 1.17 2000/03/06 12:44:24 gniibe Exp $ * * arch/sh/kernel/head.S * * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Head.S contains the SH exception handlers and startup code. */ #include .section .empty_zero_page, "aw" ENTRY(empty_zero_page) .long 1 /* MOUNT_ROOT_RDONLY */ .long 0 /* RAMDISK_FLAGS */ .long 0x0200 /* ORIG_ROOT_DEV */ .long 1 /* LOADER_TYPE */ .long 0x00360000 /* INITRD_START */ .long 0x000a0000 /* INITRD_SIZE */ .long 0 .text .balign 4096,0,4096 /* * Condition at the entry of _stext: * * BSC has already been initialized. * INTC may or may not be initialized. * VBR may or may not be initialized. * MMU may or may not be initialized. * Cache may or may not be initialized. * Hardware (including on-chip modules) may or may not be initialized. * */ ENTRY(_stext) ! Initialize Status Register mov.l 1f, $r0 ! MD=1, RB=0, BL=0, IMASK=0xF ldc $r0, $sr ! Initialize global interrupt mask mov #0, $r0 ldc $r0, $r6_bank ! mov.l 2f, $r0 mov $r0, $r15 ! Set initial r15 (stack pointer) mov #0x20, $r1 ! shll8 $r1 ! $r1 = 8192 sub $r1, $r0 ! ldc $r0, $r7_bank ! ... and init_task ! #if defined(__SH4__) ! Initialize fpu mov.l 7f, $r0 jsr @$r0 nop #endif ! Enable cache mov.l 6f, $r0 jsr @$r0 nop ! Clear BSS area mov.l 3f, $r1 add #4, $r1 mov.l 4f, $r2 mov #0, $r0 9: cmp/hs $r2, $r1 bf/s 9b ! while (r1 < r2) mov.l $r0,@-$r2 ! Start kernel mov.l 5f, $r0 jmp @$r0 nop .balign 4 1: .long 0x400000F0 ! MD=1, RB=0, BL=0, FD=0, IMASK=0xF 2: .long SYMBOL_NAME(stack) 3: .long SYMBOL_NAME(__bss_start) 4: .long SYMBOL_NAME(_end) 5: .long SYMBOL_NAME(start_kernel) 6: .long SYMBOL_NAME(cache_init) #if defined(__SH4__) 7: .long SYMBOL_NAME(fpu_init) #endif