1/* 2 * linux/arch/arm/kernel/head-nommu.S 3 * 4 * Copyright (C) 1994-2002 Russell King 5 * Copyright (C) 2003-2006 Hyok S. Choi 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * Common kernel startup code (non-paged MM) 12 * 13 */ 14#include <linux/linkage.h> 15#include <linux/init.h> 16 17#include <asm/assembler.h> 18#include <asm/mach-types.h> 19#include <asm/procinfo.h> 20#include <asm/ptrace.h> 21#include <asm/asm-offsets.h> 22#include <asm/thread_info.h> 23#include <asm/system.h> 24 25/* 26 * Kernel startup entry point. 27 * --------------------------- 28 * 29 * This is normally called from the decompressor code. The requirements 30 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, 31 * r1 = machine nr. 32 * 33 * See linux/arch/arm/tools/mach-types for the complete list of machine 34 * numbers for r1. 35 * 36 */ 37 __INIT 38 .type stext, %function 39ENTRY(stext) 40 msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode 41 @ and irqs disabled 42#ifndef CONFIG_CPU_CP15 43 ldr r9, =CONFIG_PROCESSOR_ID 44#else 45 mrc p15, 0, r9, c0, c0 @ get processor id 46#endif 47 bl __lookup_processor_type @ r5=procinfo r9=cpuid 48 movs r10, r5 @ invalid processor (r5=0)? 49 beq __error_p @ yes, error 'p' 50 bl __lookup_machine_type @ r5=machinfo 51 movs r8, r5 @ invalid machine (r5=0)? 52 beq __error_a @ yes, error 'a' 53 54 ldr r13, __switch_data @ address to jump to after 55 @ the initialization is done 56 adr lr, __after_proc_init @ return (PIC) address 57 add pc, r10, #PROCINFO_INITFUNC 58 59/* 60 * Set the Control Register and Read the process ID. 61 */ 62 .type __after_proc_init, %function 63__after_proc_init: 64#ifdef CONFIG_CPU_CP15 65 mrc p15, 0, r0, c1, c0, 0 @ read control reg 66#ifdef CONFIG_ALIGNMENT_TRAP 67 orr r0, r0, #CR_A 68#else 69 bic r0, r0, #CR_A 70#endif 71#ifdef CONFIG_CPU_DCACHE_DISABLE 72 bic r0, r0, #CR_C 73#endif 74#ifdef CONFIG_CPU_BPREDICT_DISABLE 75 bic r0, r0, #CR_Z 76#endif 77#ifdef CONFIG_CPU_ICACHE_DISABLE 78 bic r0, r0, #CR_I 79#endif 80 mcr p15, 0, r0, c1, c0, 0 @ write control reg 81#endif /* CONFIG_CPU_CP15 */ 82 83 mov pc, r13 @ clear the BSS and jump 84 @ to start_kernel 85 .ltorg 86 87#include "head-common.S" 88