OpenRTX/rtos/uC-CPU/ARM-Cortex-M/ARMv6-M/cpu_a.s

149 lines
5.7 KiB
ArmAsm

@********************************************************************************************************
@ uC/CPU
@ CPU CONFIGURATION & PORT LAYER
@
@ Copyright 2004-2020 Silicon Laboratories Inc. www.silabs.com
@
@ SPDX-License-Identifier: APACHE-2.0
@
@ This software is subject to an open source license and is distributed by
@ Silicon Laboratories Inc. pursuant to the terms of the Apache License,
@ Version 2.0 available at www.apache.org/licenses/LICENSE-2.0.
@
@********************************************************************************************************
@********************************************************************************************************
@
@ CPU PORT FILE
@
@ ARMv6-M
@ GNU C Compiler
@
@ Filename : cpu_a.s
@ Version : v1.32.00
@********************************************************************************************************
@ Note(s) : This port supports the ARM Cortex-M0, and Cortex-M0+ architectures.
@********************************************************************************************************
@********************************************************************************************************
@ PUBLIC FUNCTIONS
@********************************************************************************************************
.global CPU_IntDis
.global CPU_IntEn
.global CPU_SR_Save
.global CPU_SR_Restore
.global CPU_WaitForInt
.global CPU_WaitForExcept
@********************************************************************************************************
@ CODE GENERATION DIRECTIVES
@********************************************************************************************************
.text
.align 2
.thumb
.syntax unified
@********************************************************************************************************
@ DISABLE and ENABLE INTERRUPTS
@
@ Description : Disable/Enable interrupts.
@
@ Prototypes : void CPU_IntDis(void);
@ void CPU_IntEn (void);
@********************************************************************************************************
.thumb_func
CPU_IntDis:
CPSID I
BX LR
.thumb_func
CPU_IntEn:
CPSIE I
BX LR
@********************************************************************************************************
@ CRITICAL SECTION FUNCTIONS
@
@ Description : Disable/Enable interrupts by preserving the state of interrupts. Generally speaking, the
@ state of the interrupt disable flag is stored in the local variable 'cpu_sr' & interrupts
@ are then disabled ('cpu_sr' is allocated in all functions that need to disable interrupts).
@ The previous interrupt state is restored by copying 'cpu_sr' into the CPU's status register.
@
@ Prototypes : CPU_SR CPU_SR_Save (void);
@ void CPU_SR_Restore(CPU_SR cpu_sr);
@
@ Note(s) : (1) These functions are used in general like this :
@
@ void Task (void *p_arg)
@ {
@ CPU_SR_ALLOC(); /* Allocate storage for CPU status register */
@ :
@ :
@ CPU_CRITICAL_ENTER(); /* cpu_sr = CPU_SR_Save(); */
@ :
@ :
@ CPU_CRITICAL_EXIT(); /* CPU_SR_Restore(cpu_sr); */
@ :
@ }
@********************************************************************************************************
.thumb_func
CPU_SR_Save:
MRS R0, PRIMASK @ Set prio int mask to mask all (except faults)
CPSID I
BX LR
.thumb_func
CPU_SR_Restore: @ See Note #2.
MSR PRIMASK, R0
BX LR
@********************************************************************************************************
@ WAIT FOR INTERRUPT
@
@ Description : Enters sleep state, which will be exited when an interrupt is received.
@
@ Prototypes : void CPU_WaitForInt (void)
@
@ Argument(s) : none.
@********************************************************************************************************
.thumb_func
CPU_WaitForInt:
WFI @ Wait for interrupt
BX LR
@********************************************************************************************************
@ WAIT FOR EXCEPTION
@
@ Description : Enters sleep state, which will be exited when an exception is received.
@
@ Prototypes : void CPU_WaitForExcept (void)
@
@ Argument(s) : none.
@********************************************************************************************************
.thumb_func
CPU_WaitForExcept:
WFE @ Wait for exception
BX LR
@********************************************************************************************************
@ CPU ASSEMBLY PORT FILE END
@********************************************************************************************************
.end