| ;/* |
| ; * 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 |
| ; * |
| ; */ |
| |
| .thumb |
| |
| .ref pxCurrentTCB |
| .ref vTaskSwitchContext |
| .ref ulMaxSyscallInterruptPriority |
| |
| .def xPortPendSVHandler |
| .def ulPortGetIPSR |
| .def vPortSVCHandler |
| .def vPortStartFirstTask |
| |
| NVICOffsetConst: .word 0xE000ED08 |
| CPACRConst: .word 0xE000ED88 |
| pxCurrentTCBConst: .word pxCurrentTCB |
| ulMaxSyscallInterruptPriorityConst: .word ulMaxSyscallInterruptPriority |
| |
| ; ----------------------------------------------------------- |
| |
| .align 4 |
| ulPortGetIPSR: .asmfunc |
| mrs r0, ipsr |
| bx r14 |
| .endasmfunc |
| ; ----------------------------------------------------------- |
| |
| .align 4 |
| vPortSetInterruptMask: .asmfunc |
| push {r0} |
| ldr r0, ulMaxSyscallInterruptPriorityConst |
| msr basepri, r0 |
| pop {r0} |
| bx r14 |
| .endasmfunc |
| ; ----------------------------------------------------------- |
| |
| .align 4 |
| xPortPendSVHandler: .asmfunc |
| mrs r0, psp |
| isb |
| |
| ;/* Get the location of the current TCB. */ |
| ldr r3, pxCurrentTCBConst |
| ldr r2, [r3] |
| |
| ;/* Save the core registers. */ |
| stmdb r0!, {r4-r11} |
| |
| ;/* Save the new top of stack into the first member of the TCB. */ |
| str r0, [r2] |
| |
| stmdb sp!, {r3, r14} |
| ldr r0, ulMaxSyscallInterruptPriorityConst |
| ldr r1, [r0] |
| msr basepri, r1 |
| dsb |
| isb |
| bl vTaskSwitchContext |
| mov r0, #0 |
| msr basepri, r0 |
| ldmia sp!, {r3, r14} |
| |
| ;/* The first item in pxCurrentTCB is the task top of stack. */ |
| ldr r1, [r3] |
| ldr r0, [r1] |
| |
| ;/* Pop the core registers. */ |
| ldmia r0!, {r4-r11} |
| |
| msr psp, r0 |
| isb |
| bx r14 |
| .endasmfunc |
| |
| ; ----------------------------------------------------------- |
| |
| .align 4 |
| vPortSVCHandler: .asmfunc |
| ;/* Get the location of the current TCB. */ |
| ldr r3, pxCurrentTCBConst |
| ldr r1, [r3] |
| ldr r0, [r1] |
| ;/* Pop the core registers. */ |
| ldmia r0!, {r4-r11} |
| msr psp, r0 |
| isb |
| mov r0, #0 |
| msr basepri, r0 |
| orr r14, #0xd |
| bx r14 |
| .endasmfunc |
| |
| ; ----------------------------------------------------------- |
| |
| .align 4 |
| vPortStartFirstTask: .asmfunc |
| ;/* Use the NVIC offset register to locate the stack. */ |
| ldr r0, NVICOffsetConst |
| ldr r0, [r0] |
| ldr r0, [r0] |
| ;/* Set the msp back to the start of the stack. */ |
| msr msp, r0 |
| ;/* Clear the bit that indicates the FPU is in use in case the FPU was used |
| ;before the scheduler was started - which would otherwise result in the |
| ;unnecessary leaving of space in the SVC stack for lazy saving of FPU |
| ;registers. */ |
| mov r0, #0 |
| msr control, r0 |
| ;/* Call SVC to start the first task. */ |
| cpsie i |
| cpsie f |
| dsb |
| isb |
| svc #0 |
| .endasmfunc |
| |
| ; ----------------------------------------------------------- |