| ;/* |
| ; * 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 |
| ; * |
| ; */ |
| |
| #include "FreeRTOSConfig.h" |
| |
| ; Variables used by scheduler |
| ;------------------------------------------------------------------------------ |
| EXTERN pxCurrentTCB |
| EXTERN usCriticalNesting |
| |
| ;------------------------------------------------------------------------------ |
| ; portSAVE_CONTEXT MACRO |
| ; Saves the context of the general purpose registers, CS and ES (only in far |
| ; memory mode) registers the usCriticalNesting Value and the Stack Pointer |
| ; of the active Task onto the task stack |
| ;------------------------------------------------------------------------------ |
| portSAVE_CONTEXT MACRO |
| |
| PUSH AX ; Save AX Register to stack. |
| PUSH HL |
| MOV A, CS ; Save CS register. |
| XCH A, X |
| MOV A, ES ; Save ES register. |
| PUSH AX |
| PUSH DE ; Save the remaining general purpose registers. |
| PUSH BC |
| MOVW AX, usCriticalNesting ; Save the usCriticalNesting value. |
| PUSH AX |
| MOVW AX, pxCurrentTCB ; Save the Stack pointer. |
| MOVW HL, AX |
| MOVW AX, SP |
| MOVW [HL], AX |
| ENDM |
| ;------------------------------------------------------------------------------ |
| |
| ;------------------------------------------------------------------------------ |
| ; portRESTORE_CONTEXT MACRO |
| ; Restores the task Stack Pointer then use this to restore usCriticalNesting, |
| ; general purpose registers and the CS and ES (only in far memory mode) |
| ; of the selected task from the task stack |
| ;------------------------------------------------------------------------------ |
| portRESTORE_CONTEXT MACRO |
| MOVW AX, pxCurrentTCB ; Restore the Stack pointer. |
| MOVW HL, AX |
| MOVW AX, [HL] |
| MOVW SP, AX |
| POP AX ; Restore usCriticalNesting value. |
| MOVW usCriticalNesting, AX |
| POP BC ; Restore the necessary general purpose registers. |
| POP DE |
| POP AX ; Restore the ES register. |
| MOV ES, A |
| XCH A, X ; Restore the CS register. |
| MOV CS, A |
| POP HL ; Restore general purpose register HL. |
| POP AX ; Restore AX. |
| ENDM |
| ;------------------------------------------------------------------------------ |