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- /*
- * FreeRTOS Kernel V10.4.6
- * 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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