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/*
* FreeRTOS Kernel V10.5.0
* 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
*
*/
/* 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
*/
.macro portSAVE_CONTEXT
SEL RB0
/* Save AX Register to stack. */
PUSH AX
PUSH HL
/* Save CS register. */
MOV A, CS
XCH A, X
/* Save ES register. */
MOV A, ES
PUSH AX
/* Save the remaining general purpose registers from bank 0. */
PUSH DE
PUSH BC
/* Save the other register banks - only necessary in the GCC port. */
SEL RB1
PUSH AX
PUSH BC
PUSH DE
PUSH HL
SEL RB2
PUSH AX
PUSH BC
PUSH DE
PUSH HL
/* Registers in bank 3 are for ISR use only so don't need saving. */
SEL RB0
/* Save the usCriticalNesting value. */
MOVW AX, !_usCriticalNesting
PUSH AX
/* Save the Stack pointer. */
MOVW AX, !_pxCurrentTCB
MOVW HL, AX
MOVW AX, SP
MOVW [HL], AX
/* Switch stack pointers. */
movw sp,#_stack /* Set stack pointer */
.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
*/
.macro portRESTORE_CONTEXT MACRO
SEL RB0
/* Restore the Stack pointer. */
MOVW AX, !_pxCurrentTCB
MOVW HL, AX
MOVW AX, [HL]
MOVW SP, AX
/* Restore usCriticalNesting value. */
POP AX
MOVW !_usCriticalNesting, AX
/* Restore the alternative register banks - only necessary in the GCC
port. Register bank 3 is dedicated for interrupts use so is not saved or
restored. */
SEL RB2
POP HL
POP DE
POP BC
POP AX
SEL RB1
POP HL
POP DE
POP BC
POP AX
SEL RB0
/* Restore the necessary general purpose registers. */
POP BC
POP DE
/* Restore the ES register. */
POP AX
MOV ES, A
/* Restore the CS register. */
XCH A, X
MOV CS, A
/* Restore general purpose register HL. */
POP HL
/* Restore AX. */
POP AX
.endm
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