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/ptrace.h> 20#include <asm/asm-offsets.h> 21#include <asm/thread_info.h> 22#include <asm/system.h> 23 24/* 25 * Kernel startup entry point. 26 * --------------------------- 27 * 28 * This is normally called from the decompressor code. The requirements 29 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, 30 * r1 = machine nr. 31 * 32 * See linux/arch/arm/tools/mach-types for the complete list of machine 33 * numbers for r1. 34 * 35 */ 36 .section ".text.head", "ax" 37 .type stext, %function 38ENTRY(stext) 39 msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode 40 @ and irqs disabled 41#ifndef CONFIG_CPU_CP15 42 ldr r9, =CONFIG_PROCESSOR_ID 43#else 44 mrc p15, 0, r9, c0, c0 @ get processor id 45#endif 46 bl __lookup_processor_type @ r5=procinfo r9=cpuid 47 movs r10, r5 @ invalid processor (r5=0)? 48 beq __error_p @ yes, error 'p' 49 bl __lookup_machine_type @ r5=machinfo 50 movs r8, r5 @ invalid machine (r5=0)? 51 beq __error_a @ yes, error 'a' 52 53 ldr r13, __switch_data @ address to jump to after 54 @ the initialization is done 55 adr lr, __after_proc_init @ return (PIC) address 56 add pc, r10, #PROCINFO_INITFUNC 57 58/* 59 * Set the Control Register and Read the process ID. 60 */ 61 .type __after_proc_init, %function 62__after_proc_init: 63#ifdef CONFIG_CPU_CP15 64 mrc p15, 0, r0, c1, c0, 0 @ read control reg 65#ifdef CONFIG_ALIGNMENT_TRAP 66 orr r0, r0, #CR_A 67#else 68 bic r0, r0, #CR_A 69#endif 70#ifdef CONFIG_CPU_DCACHE_DISABLE 71 bic r0, r0, #CR_C 72#endif 73#ifdef CONFIG_CPU_BPREDICT_DISABLE 74 bic r0, r0, #CR_Z 75#endif 76#ifdef CONFIG_CPU_ICACHE_DISABLE 77 bic r0, r0, #CR_I 78#endif 79#ifdef CONFIG_CPU_HIGH_VECTOR 80 orr r0, r0, #CR_V 81#else 82 bic r0, r0, #CR_V 83#endif 84 mcr p15, 0, r0, c1, c0, 0 @ write control reg 85#endif /* CONFIG_CPU_CP15 */ 86 87 mov pc, r13 @ clear the BSS and jump 88 @ to start_kernel 89 .ltorg 90 91#include "head-common.S" 92