diff options
Diffstat (limited to 'applications/threadx_demo/tx_initialize_low_level.c')
| -rw-r--r-- | applications/threadx_demo/tx_initialize_low_level.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/applications/threadx_demo/tx_initialize_low_level.c b/applications/threadx_demo/tx_initialize_low_level.c new file mode 100644 index 0000000..f709cb2 --- /dev/null +++ b/applications/threadx_demo/tx_initialize_low_level.c @@ -0,0 +1,116 @@ +/* + * Copyright (c) 2020-2021 Arm Limited. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/**************************************************************************** + * Includes + ****************************************************************************/ +#include "tx_api.h" +#include <stdio.h> + +/**************************************************************************** + * Defines + ****************************************************************************/ +#define SYSTEM_CLOCK 6000000 +#define SYSTICK_CYCLES ((SYSTEM_CLOCK / 100) - 1) + +/**************************************************************************** + * Externs + ****************************************************************************/ +void _tx_timer_interrupt(void); + +/**************************************************************************** + * Functions + ****************************************************************************/ + +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_initialize_low_level Cortex-M4/GNU */ +/* 6.1 */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for any low-level processor */ +/* initialization, including setting up interrupt vectors, setting */ +/* up a periodic timer interrupt source, saving the system stack */ +/* pointer for use in ISR processing later, and finding the first */ +/* available RAM memory address for tx_application_define. */ +/* this function has an empty implementation in this example. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* _tx_initialize_kernel_enter ThreadX entry function */ +/* */ +/**************************************************************************/ +VOID _tx_initialize_low_level(VOID) { + __asm__ volatile( + /* Disable interrupts during ThreadX initialization. */ + " CPSID i\n" + /* Enable the cycle count register. */ + " LDR r0, =0xE0001000\n" // Build address of DWT register + " LDR r1, [r0]\n" // Pickup the current value + " ORR r1, r1, #1\n" // Set the CYCCNTENA bit + " STR r1, [r0]\n" // Enable the cycle count register + /* Configure SysTick for 100Hz clock, or 16384 cycles if no reference. */ + " MOV r0, #0xE000E000\n" // Build address of NVIC registers + " LDR r1, =59999\n" // 59,999 = SYSTICK_CYCLES = ((6,000,000 / 100) -1) + " STR r1, [r0, #0x14]\n" // Setup SysTick Reload Value + " MOV r1, #0x7\n" // Build SysTick Control Enable Value + " STR r1, [r0, #0x10]\n" // Setup SysTick Control + /* Configure handler priorities. */ + " LDR r1, =0x00000000\n" // Rsrv, UsgF, BusF, MemM + " STR r1, [r0, #0xD18]\n" // Setup System Handlers 4-7 Priority Registers + " LDR r1, =0xFF000000\n" // SVCl, Rsrv, Rsrv, Rsrv + " STR r1, [r0, #0xD1C]\n" // Setup System Handlers 8-11 Priority Registers + // Note: SVC must be lowest priority, which is 0xFF + " LDR r1, =0x40FF0000\n" // SysT, PnSV, Rsrv, DbgM + " STR r1, [r0, #0xD20]\n" // Setup System Handlers 12-15 Priority Registers + // Note: PnSV must be lowest priority, which is 0xFF + /* Return to caller. */ + " BX lr\n"); +} + +/* SysTick_Handler has a generic interrupt handler template. */ +/* to implement a new handler, replace the call to */ +/* _tx_timer_interrupt to some other c function */ +VOID SysTick_Handler(VOID) { +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + _tx_execution_isr_enter(); // Call the ISR enter function +#endif + + _tx_timer_interrupt(); + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + _tx_execution_isr_exit(); // Call the ISR exit function +#endif + + return; +} |