1 ;/* 2 ; * FreeRTOS Kernel V10.6.2 3 ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. 4 ; * 5 ; * SPDX-License-Identifier: MIT 6 ; * 7 ; * Permission is hereby granted, free of charge, to any person obtaining a copy of 8 ; * this software and associated documentation files (the "Software"), to deal in 9 ; * the Software without restriction, including without limitation the rights to 10 ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of 11 ; * the Software, and to permit persons to whom the Software is furnished to do so, 12 ; * subject to the following conditions: 13 ; * 14 ; * The above copyright notice and this permission notice shall be included in all 15 ; * copies or substantial portions of the Software. 16 ; * 17 ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS 19 ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR 20 ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 21 ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 ; * 24 ; * https://www.FreeRTOS.org 25 ; * https://github.com/FreeRTOS 26 ; * 27 ; */ 28 29 #include "FreeRTOSConfig.h" 30 31 ; Variables used by scheduler 32 ;------------------------------------------------------------------------------ 33 EXTERN pxCurrentTCB 34 EXTERN usCriticalNesting 35 36 ;------------------------------------------------------------------------------ 37 ; portSAVE_CONTEXT MACRO 38 ; Saves the context of the general purpose registers, CS and ES (only in far 39 ; memory mode) registers the usCriticalNesting Value and the Stack Pointer 40 ; of the active Task onto the task stack 41 ;------------------------------------------------------------------------------ 42 portSAVE_CONTEXT MACRO 43 44 PUSH AX ; Save AX Register to stack. 45 PUSH HL 46 MOV A, CS ; Save CS register. 47 XCH A, X 48 MOV A, ES ; Save ES register. 49 PUSH AX 50 PUSH DE ; Save the remaining general purpose registers. 51 PUSH BC 52 MOVW AX, usCriticalNesting ; Save the usCriticalNesting value. 53 PUSH AX 54 MOVW AX, pxCurrentTCB ; Save the Stack pointer. 55 MOVW HL, AX 56 MOVW AX, SP 57 MOVW [HL], AX 58 ENDM 59 ;------------------------------------------------------------------------------ 60 61 ;------------------------------------------------------------------------------ 62 ; portRESTORE_CONTEXT MACRO 63 ; Restores the task Stack Pointer then use this to restore usCriticalNesting, 64 ; general purpose registers and the CS and ES (only in far memory mode) 65 ; of the selected task from the task stack 66 ;------------------------------------------------------------------------------ 67 portRESTORE_CONTEXT MACRO 68 MOVW AX, pxCurrentTCB ; Restore the Stack pointer. 69 MOVW HL, AX 70 MOVW AX, [HL] 71 MOVW SP, AX 72 POP AX ; Restore usCriticalNesting value. 73 MOVW usCriticalNesting, AX 74 POP BC ; Restore the necessary general purpose registers. 75 POP DE 76 POP AX ; Restore the ES register. 77 MOV ES, A 78 XCH A, X ; Restore the CS register. 79 MOV CS, A 80 POP HL ; Restore general purpose register HL. 81 POP AX ; Restore AX. 82 ENDM 83 ;------------------------------------------------------------------------------ 84
