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/*
* 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)
* for 32-bit CPUs which has a process ID register(CP15).
*
*/
#include <linux/config.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/mach-types.h>
#include <asm/procinfo.h>
#include <asm/ptrace.h>
#include <asm/constants.h>
#include <asm/system.h>
#define PROCINFO_INITFUNC 12
/*
* 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.
*
*/
__INIT
.type stext, %function
ENTRY(stext)
msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
@ and irqs disabled
mrc p15, 0, r9, c0, c0 @ get processor id
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?
beq __error_p @ yes, error 'p'
bl __lookup_machine_type @ r5=machinfo
movs r8, r5 @ invalid machine (r5=0)?
beq __error_a @ yes, error 'a'
ldr r13, __switch_data @ address to jump to after
@ the initialization is done
adr lr, __after_proc_init @ return (PIC) address
add pc, r10, #PROCINFO_INITFUNC
/*
* Set the Control Register and Read the process ID.
*/
.type __after_proc_init, %function
__after_proc_init:
mrc p15, 0, r0, c1, c0, 0 @ read control reg
#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
mcr p15, 0, r0, c1, c0, 0 @ write control reg
mov pc, r13 @ clear the BSS and jump
@ to start_kernel
#include "head-common.S"
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