| /* |
| * 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 "msp430.h" |
| #include "FreeRTOSConfig.h" |
| #include "data_model.h" |
| |
| IMPORT xTaskIncrementTick |
| IMPORT vTaskSwitchContext |
| IMPORT vPortSetupTimerInterrupt |
| IMPORT pxCurrentTCB |
| IMPORT usCriticalNesting |
| |
| EXPORT vPortTickISR |
| EXPORT vPortYield |
| EXPORT xPortStartScheduler |
| |
| portSAVE_CONTEXT macro |
| |
| /* Save the remaining registers. */ |
| pushm_x #12, r15 |
| mov.w &usCriticalNesting, r14 |
| push_x r14 |
| mov_x &pxCurrentTCB, r12 |
| mov_x sp, 0( r12 ) |
| endm |
| /*-----------------------------------------------------------*/ |
| |
| portRESTORE_CONTEXT macro |
| |
| mov_x &pxCurrentTCB, r12 |
| mov_x @r12, sp |
| pop_x r15 |
| mov.w r15, &usCriticalNesting |
| popm_x #12, r15 |
| nop |
| pop.w sr |
| nop |
| reta |
| endm |
| /*-----------------------------------------------------------*/ |
| |
| |
| /* |
| * The RTOS tick ISR. |
| * |
| * If the cooperative scheduler is in use this simply increments the tick |
| * count. |
| * |
| * If the preemptive scheduler is in use a context switch can also occur. |
| */ |
| |
| RSEG CODE |
| EVEN |
| |
| vPortTickISR: |
| |
| /* The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs |
| to save it manually before it gets modified (interrupts get disabled). |
| Entering through this interrupt means the SR is already on the stack, but |
| this keeps the stack frames identical. */ |
| push.w sr |
| portSAVE_CONTEXT |
| |
| calla #xTaskIncrementTick |
| cmp.w #0x0, R12 |
| jeq SkipContextSwitch |
| calla #vTaskSwitchContext |
| SkipContextSwitch: |
| portRESTORE_CONTEXT |
| /*-----------------------------------------------------------*/ |
| |
| /* |
| * Manual context switch called by the portYIELD() macro. |
| */ |
| EVEN |
| |
| vPortYield: |
| |
| /* The sr needs saving before it is modified. */ |
| push.w sr |
| |
| /* Now the SR is stacked interrupts can be disabled. */ |
| dint |
| nop |
| |
| /* Save the context of the current task. */ |
| portSAVE_CONTEXT |
| |
| /* Select the next task to run. */ |
| calla #vTaskSwitchContext |
| |
| /* Restore the context of the new task. */ |
| portRESTORE_CONTEXT |
| /*-----------------------------------------------------------*/ |
| |
| |
| /* |
| * Start off the scheduler by initialising the RTOS tick timer, then restoring |
| * the context of the first task. |
| */ |
| EVEN |
| |
| xPortStartScheduler: |
| |
| /* Setup the hardware to generate the tick. Interrupts are disabled |
| when this function is called. */ |
| calla #vPortSetupTimerInterrupt |
| |
| /* Restore the context of the first task that is going to run. */ |
| portRESTORE_CONTEXT |
| /*-----------------------------------------------------------*/ |
| |
| END |