kernel-ark/arch/arm/vfp/entry.S
Russell King 5d4cae5fe2 [ARM] VFP: fix section mismatch error
Fix a real section mismatch issue; the test code is thrown away after
initialisation, but if we do not detect the VFP hardware, it is left
hooked into the exception handler.  Any VFP instructions which are
subsequently executed risk calling the discarded exception handler.

Introduce a new "null" handler which returns to the "unrecognised
fault" return address.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-06-10 12:22:20 +01:00

53 lines
1.2 KiB
ArmAsm

/*
* linux/arch/arm/vfp/entry.S
*
* Copyright (C) 2004 ARM Limited.
* Written by Deep Blue Solutions Limited.
*
* 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.
*
* Basic entry code, called from the kernel's undefined instruction trap.
* r0 = faulted instruction
* r5 = faulted PC+4
* r9 = successful return
* r10 = thread_info structure
* lr = failure return
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/vfpmacros.h>
.globl do_vfp
do_vfp:
enable_irq
ldr r4, .LCvfp
ldr r11, [r10, #TI_CPU] @ CPU number
add r10, r10, #TI_VFPSTATE @ r10 = workspace
ldr pc, [r4] @ call VFP entry point
ENTRY(vfp_null_entry)
mov pc, lr
ENDPROC(vfp_null_entry)
.LCvfp:
.word vfp_vector
@ This code is called if the VFP does not exist. It needs to flag the
@ failure to the VFP initialisation code.
__INIT
.globl vfp_testing_entry
vfp_testing_entry:
ldr r0, VFP_arch_address
str r5, [r0] @ known non-zero value
mov pc, r9 @ we have handled the fault
VFP_arch_address:
.word VFP_arch
__FINIT