/* * linux/arch/arm/kernel/head-nommu.S * * Copyright (C) 1994-2002 Russell King * Copyright (C) 2003-2006 Hyok S. Choi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Common kernel startup code (non-paged MM) * */ #include <linux/linkage.h> #include <linux/init.h> #include <asm/assembler.h> #include <asm/ptrace.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> #include <asm/system.h> /* * Kernel startup entry point. * --------------------------- * * This is normally called from the decompressor code. The requirements * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, * r1 = machine nr. * * See linux/arch/arm/tools/mach-types for the complete list of machine * numbers for r1. * */ .arm __HEAD ENTRY(stext) THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. THUMB( bx r9 ) @ If this is a Thumb-2 kernel, THUMB( .thumb ) @ switch to Thumb now. THUMB(1: ) setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode @ and irqs disabled #ifndef CONFIG_CPU_CP15 ldr r9, =CONFIG_PROCESSOR_ID #else mrc p15, 0, r9, c0, c0 @ get processor id #endif bl __lookup_processor_type @ r5=procinfo r9=cpuid movs r10, r5 @ invalid processor (r5=0)? beq __error_p @ yes, error 'p' adr lr, BSYM(__after_proc_init) @ return (PIC) address ARM( add pc, r10, #PROCINFO_INITFUNC ) THUMB( add r12, r10, #PROCINFO_INITFUNC ) THUMB( mov pc, r12 ) ENDPROC(stext) /* * Set the Control Register and Read the process ID. */ __after_proc_init: #ifdef CONFIG_CPU_CP15 /* * CP15 system control register value returned in r0 from * the CPU init function. */ #ifdef CONFIG_ALIGNMENT_TRAP orr r0, r0, #CR_A #else bic r0, r0, #CR_A #endif #ifdef CONFIG_CPU_DCACHE_DISABLE bic r0, r0, #CR_C #endif #ifdef CONFIG_CPU_BPREDICT_DISABLE bic r0, r0, #CR_Z #endif #ifdef CONFIG_CPU_ICACHE_DISABLE bic r0, r0, #CR_I #endif #ifdef CONFIG_CPU_HIGH_VECTOR orr r0, r0, #CR_V #else bic r0, r0, #CR_V #endif mcr p15, 0, r0, c1, c0, 0 @ write control reg #endif /* CONFIG_CPU_CP15 */ b __mmap_switched @ clear the BSS and jump @ to start_kernel ENDPROC(__after_proc_init) .ltorg #include "head-common.S"