6afd6fae1d
In nommu mode, the exception vector location depends on the platforms. Some of the implementations may have some special exception control forwarding method in their ROM/flash and for some of them has its own re-mapping mechanism by the h/w. This patch introduces a special configuration CONFIG_CPU_HIGH_VECTOR which turns on the CR_V bit in nommu mode. The CR_V bit is turned off by default. This feature depends on CP15 and does not supported by ARM740. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
92 lines
2.3 KiB
ArmAsm
92 lines
2.3 KiB
ArmAsm
/*
|
|
* 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/mach-types.h>
|
|
#include <asm/procinfo.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.
|
|
*
|
|
*/
|
|
__INIT
|
|
.type stext, %function
|
|
ENTRY(stext)
|
|
msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ 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'
|
|
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:
|
|
#ifdef CONFIG_CPU_CP15
|
|
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
|
|
#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 */
|
|
|
|
mov pc, r13 @ clear the BSS and jump
|
|
@ to start_kernel
|
|
.ltorg
|
|
|
|
#include "head-common.S"
|