1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
;/*
; * FreeRTOS V202112.00
; * 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
|
