;/* ; * FreeRTOS Kernel V10.3.0 ; * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. ; * ; * 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. ; * ; * http://www.FreeRTOS.org ; * http://aws.amazon.com/freertos ; * ; * 1 tab == 4 spaces! ; */ INCLUDE portmacro.inc ;The UART interrupt entry point is defined within an assembly wrapper ;within this file. This takes care of the task context saving before it ;calls the main handler (vUART_ISRHandler()) which is written in C within ;serial.c. The execution of the handler can unblock tasks that were blocked ;waiting for UART events. Once the handler completes the asm wrapper ;finishes off by restoring the context of whichever task is now selected to ;enter the RUNNING state (which might now be a different task to that which ;was originally interrupted. IMPORT vUART_ISRHandler EXPORT vUART_ISREntry ;/* Interrupt entry must always be in ARM mode. */ ARM AREA |.text|, CODE, READONLY vUART_ISREntry PRESERVE8 ; Save the context of the interrupted task. portSAVE_CONTEXT ; Call the C handler function - defined within serial.c. LDR R0, =vUART_ISRHandler MOV LR, PC BX R0 ; Finish off by restoring the context of the task that has been chosen to ; run next - which might be a different task to that which was originally ; interrupted. portRESTORE_CONTEXT END