| Lior Dekel | 489e40b | 2021-08-02 12:03:55 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2020-2021 Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: Apache-2.0 |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the License); you may |
| 7 | * not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| 14 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | /**************************************************************************** |
| 20 | * Includes |
| 21 | ****************************************************************************/ |
| 22 | #include "tx_api.h" |
| 23 | #include <stdio.h> |
| 24 | |
| 25 | /**************************************************************************** |
| 26 | * Defines |
| 27 | ****************************************************************************/ |
| 28 | #define SYSTEM_CLOCK 6000000 |
| 29 | #define SYSTICK_CYCLES ((SYSTEM_CLOCK / 100) - 1) |
| 30 | |
| 31 | /**************************************************************************** |
| 32 | * Externs |
| 33 | ****************************************************************************/ |
| 34 | void _tx_timer_interrupt(void); |
| 35 | |
| 36 | /**************************************************************************** |
| 37 | * Functions |
| 38 | ****************************************************************************/ |
| 39 | |
| 40 | /**************************************************************************/ |
| 41 | /* */ |
| 42 | /* FUNCTION RELEASE */ |
| 43 | /* */ |
| 44 | /* _tx_initialize_low_level Cortex-M4/GNU */ |
| 45 | /* 6.1 */ |
| 46 | /* */ |
| 47 | /* DESCRIPTION */ |
| 48 | /* */ |
| 49 | /* This function is responsible for any low-level processor */ |
| 50 | /* initialization, including setting up interrupt vectors, setting */ |
| 51 | /* up a periodic timer interrupt source, saving the system stack */ |
| 52 | /* pointer for use in ISR processing later, and finding the first */ |
| 53 | /* available RAM memory address for tx_application_define. */ |
| 54 | /* this function has an empty implementation in this example. */ |
| 55 | /* */ |
| 56 | /* INPUT */ |
| 57 | /* */ |
| 58 | /* None */ |
| 59 | /* */ |
| 60 | /* OUTPUT */ |
| 61 | /* */ |
| 62 | /* None */ |
| 63 | /* */ |
| 64 | /* CALLS */ |
| 65 | /* */ |
| 66 | /* None */ |
| 67 | /* */ |
| 68 | /* CALLED BY */ |
| 69 | /* */ |
| 70 | /* _tx_initialize_kernel_enter ThreadX entry function */ |
| 71 | /* */ |
| 72 | /**************************************************************************/ |
| 73 | VOID _tx_initialize_low_level(VOID) { |
| 74 | __asm__ volatile( |
| 75 | /* Disable interrupts during ThreadX initialization. */ |
| 76 | " CPSID i\n" |
| 77 | /* Enable the cycle count register. */ |
| 78 | " LDR r0, =0xE0001000\n" // Build address of DWT register |
| 79 | " LDR r1, [r0]\n" // Pickup the current value |
| 80 | " ORR r1, r1, #1\n" // Set the CYCCNTENA bit |
| 81 | " STR r1, [r0]\n" // Enable the cycle count register |
| 82 | /* Configure SysTick for 100Hz clock, or 16384 cycles if no reference. */ |
| 83 | " MOV r0, #0xE000E000\n" // Build address of NVIC registers |
| 84 | " LDR r1, =59999\n" // 59,999 = SYSTICK_CYCLES = ((6,000,000 / 100) -1) |
| 85 | " STR r1, [r0, #0x14]\n" // Setup SysTick Reload Value |
| 86 | " MOV r1, #0x7\n" // Build SysTick Control Enable Value |
| 87 | " STR r1, [r0, #0x10]\n" // Setup SysTick Control |
| 88 | /* Configure handler priorities. */ |
| 89 | " LDR r1, =0x00000000\n" // Rsrv, UsgF, BusF, MemM |
| 90 | " STR r1, [r0, #0xD18]\n" // Setup System Handlers 4-7 Priority Registers |
| 91 | " LDR r1, =0xFF000000\n" // SVCl, Rsrv, Rsrv, Rsrv |
| 92 | " STR r1, [r0, #0xD1C]\n" // Setup System Handlers 8-11 Priority Registers |
| 93 | // Note: SVC must be lowest priority, which is 0xFF |
| 94 | " LDR r1, =0x40FF0000\n" // SysT, PnSV, Rsrv, DbgM |
| 95 | " STR r1, [r0, #0xD20]\n" // Setup System Handlers 12-15 Priority Registers |
| 96 | // Note: PnSV must be lowest priority, which is 0xFF |
| 97 | /* Return to caller. */ |
| 98 | " BX lr\n"); |
| 99 | } |
| 100 | |
| 101 | /* SysTick_Handler has a generic interrupt handler template. */ |
| 102 | /* to implement a new handler, replace the call to */ |
| 103 | /* _tx_timer_interrupt to some other c function */ |
| 104 | VOID SysTick_Handler(VOID) { |
| 105 | #ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY |
| 106 | _tx_execution_isr_enter(); // Call the ISR enter function |
| 107 | #endif |
| 108 | |
| 109 | _tx_timer_interrupt(); |
| 110 | |
| 111 | #ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY |
| 112 | _tx_execution_isr_exit(); // Call the ISR exit function |
| 113 | #endif |
| 114 | |
| 115 | return; |
| 116 | } |