blob: 7ceed2d599c9b8e75e391ea49bd6180a24e4ae0e [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
; *
; */
#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
;------------------------------------------------------------------------------