zephyr/arch/arm/core/fault_s.S

117 lines
2.9 KiB
ArmAsm

/*
* Copyright (c) 2013-2014 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief Fault handlers for ARM Cortex-M
*
* Fault handlers for ARM Cortex-M processors.
*/
#define _ASMLANGUAGE
#include <toolchain.h>
#include <sections.h>
#include <arch/cpu.h>
_ASM_FILE_PROLOGUE
GTEXT(_Fault)
GTEXT(__hard_fault)
#if !defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
GTEXT(__mpu_fault)
GTEXT(__bus_fault)
GTEXT(__usage_fault)
GTEXT(__debug_monitor)
#endif
GTEXT(__reserved)
/**
*
* @brief Fault handler installed in the fault and reserved vectors
*
* Entry point for the hard fault, MPU fault, bus fault, usage fault, debug
* monitor and reserved exceptions.
*
* Save the values of the MSP and PSP in r0 and r1 respectively, so the first
* and second parameters to the _Fault() C function that will handle the rest.
* This has to be done because at this point we do not know if the fault
* happened while handling an exception or not, and thus the ESF could be on
* either stack. _Fault() will find out where the ESF resides.
*
* Provides these symbols:
*
* __hard_fault
* __mpu_fault
* __bus_fault
* __usage_fault
* __debug_monitor
* __reserved
*/
SECTION_SUBSEC_FUNC(TEXT,__fault,__hard_fault)
#if !defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
SECTION_SUBSEC_FUNC(TEXT,__fault,__mpu_fault)
SECTION_SUBSEC_FUNC(TEXT,__fault,__bus_fault)
SECTION_SUBSEC_FUNC(TEXT,__fault,__usage_fault)
SECTION_SUBSEC_FUNC(TEXT,__fault,__debug_monitor)
#endif
SECTION_SUBSEC_FUNC(TEXT,__fault,__reserved)
#if defined(CONFIG_CPU_CORTEX_M0_M0PLUS)
/* force unlock interrupts */
cpsie i
/* Use EXC_RETURN state to find out if stack frame is on the
* MSP or PSP
*/
ldr r0, =0x4
mov r1, lr
tst r1, r0
beq _stack_frame_msp
mrs r0, PSP
bne _stack_frame_endif
_stack_frame_msp:
mrs r0, MSP
_stack_frame_endif:
#else /* CONFIG_CPU_CORTEX_M3_M4 */
/* force unlock interrupts */
eors.n r0, r0
msr BASEPRI, r0
/* this reimplements _ScbIsNestedExc() */
ldr ip, =_SCS_ICSR
ldr ip, [ip]
ands.w ip, #_SCS_ICSR_RETTOBASE
ite eq /* is the RETTOBASE bit zero ? */
mrseq r0, MSP /* if so, we're not returning to thread mode,
* thus this is a nested exception: the stack
* frame is on the MSP */
mrsne r0, PSP /* if not, we are returning to thread mode, thus
* this is not a nested exception: the stack
* frame is on the PSP */
#endif /* CONFIG_CPU_CORTEX_M0_M0PLUS */
push {lr}
bl _Fault
pop {pc}
.end