blob: f9dcc6c6a5a17868bd00abe6d8a3fc496974b47a [file] [log] [blame]
;/*
; * FreeRTOS Kernel <DEVELOPMENT BRANCH>
; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
; *
; * SPDX-License-Identifier: MIT
; *
; * Permission is hereby granted, free of charge, to any person obtaining a copy of
; * this software and associated documentation files (the "Software"), to deal in
; * the Software without restriction, including without limitation the rights to
; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
; * the Software, and to permit persons to whom the Software is furnished to do so,
; * subject to the following conditions:
; *
; * The above copyright notice and this permission notice shall be included in all
; * copies or substantial portions of the Software.
; *
; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
; *
; * https://www.FreeRTOS.org
; * https://github.com/FreeRTOS
; *
; */
; * The definition of the "register test" tasks, as described at the top of
; * main.c
.include data_model.h
.global xTaskIncrementTick
.global vTaskSwitchContext
.global vPortSetupTimerInterrupt
.global pxCurrentTCB
.global usCriticalNesting
.def vPortPreemptiveTickISR
.def vPortCooperativeTickISR
.def vPortYield
.def xPortStartScheduler
;-----------------------------------------------------------
portSAVE_CONTEXT .macro
;Save the remaining registers.
pushm_x #12, r15
mov.w &usCriticalNesting, r14
push_x r14
mov_x &pxCurrentTCB, r12
mov_x sp, 0( r12 )
.endm
;-----------------------------------------------------------
portRESTORE_CONTEXT .macro
mov_x &pxCurrentTCB, r12
mov_x @r12, sp
pop_x r15
mov.w r15, &usCriticalNesting
popm_x #12, r15
nop
pop.w sr
nop
ret_x
.endm
;-----------------------------------------------------------
;*
;* The RTOS tick ISR.
;*
;* If the cooperative scheduler is in use this simply increments the tick
;* count.
;*
;* If the preemptive scheduler is in use a context switch can also occur.
;*/
.text
.align 2
vPortPreemptiveTickISR: .asmfunc
; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
;to save it manually before it gets modified (interrupts get disabled).
push.w sr
portSAVE_CONTEXT
call_x #xTaskIncrementTick
call_x #vTaskSwitchContext
portRESTORE_CONTEXT
.endasmfunc
;-----------------------------------------------------------
.align 2
vPortCooperativeTickISR: .asmfunc
; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
;to save it manually before it gets modified (interrupts get disabled).
push.w sr
portSAVE_CONTEXT
call_x #xTaskIncrementTick
portRESTORE_CONTEXT
.endasmfunc
;-----------------------------------------------------------
;
; Manual context switch called by the portYIELD() macro.
;
.align 2
vPortYield: .asmfunc
; The sr needs saving before it is modified.
push.w sr
; Now the SR is stacked we can disable interrupts.
dint
nop
; Save the context of the current task.
portSAVE_CONTEXT
; Select the next task to run.
call_x #vTaskSwitchContext
; Restore the context of the new task.
portRESTORE_CONTEXT
.endasmfunc
;-----------------------------------------------------------
;
; Start off the scheduler by initialising the RTOS tick timer, then restoring
; the context of the first task.
;
.align 2
xPortStartScheduler: .asmfunc
; Setup the hardware to generate the tick. Interrupts are disabled
; when this function is called.
call_x #vPortSetupTimerInterrupt
; Restore the context of the first task that is going to run.
portRESTORE_CONTEXT
.endasmfunc
;-----------------------------------------------------------
.end