Firmware2/buildroot/share/PlatformIO/variants/MARLIN_ARTILLERY_RUBY/startup.S
2022-12-16 14:09:09 -06:00

125 lines
4.4 KiB
ArmAsm

/**
******************************************************************************
* @file startup_stm32f401xc.s
* @author MCD Application Team
* @version V2.4.2
* @date 13-November-2015
* @brief STM32F401xCxx Devices vector table for GCC based toolchains.
* This module performs:
* - Set the initial SP
* - Set the initial PC == Reset_Handler,
* - Set the vector table entries with the exceptions ISR address
* - Branches to main in the C library (which eventually
* calls main()).
* After Reset the Cortex-M4 processor is in Thread mode,
* priority is Privileged, and the Stack is set to Main.
******************************************************************************
* @attention
*
* Copyright (c) 2015 STMicroelectronics
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
*/
.syntax unified
.cpu cortex-m4
.fpu softvfp
.thumb
/**
* @brief This is the code that gets called when the processor first
* starts execution following a reset event. Only the absolutely
* necessary set is performed, after which the application
* supplied main() routine is called.
* @param None
* @retval : None
*/
.section .text.Reset_Handler
.globl Reset_Handler
.type Reset_Handler, %function
Reset_Handler:
/* Check for magic code at the end of SRAM to detemine whether to jump to DFU */
ldr r0, =0x2000FFF0 // End of SRAM for your CPU
ldr r1, =0xDEADBEEF
ldr r2, [r0, #0]
str r0, [r0, #0] // Invalidate
cmp r2, r1
beq Jump_To_DFU
/* Original Reset_Handler code */
ldr sp, =_estack /* set stack pointer */
/* Copy the data segment initializers from flash to SRAM */
movs r1, #0
b LoopCopyDataInit
CopyDataInit:
ldr r3, =_sidata
ldr r3, [r3, r1]
str r3, [r0, r1]
adds r1, r1, #4
LoopCopyDataInit:
ldr r0, =_sdata
ldr r3, =_edata
adds r2, r0, r1
cmp r2, r3
bcc CopyDataInit
ldr r2, =_sbss
b LoopFillZerobss
/* Zero fill the bss segment. */
FillZerobss:
movs r3, #0
str r3, [r2], #4
LoopFillZerobss:
ldr r3, = _ebss
cmp r2, r3
bcc FillZerobss
/* Call the clock system intitialization function.*/
bl SystemInit
/* Call static constructors */
bl __libc_init_array
/* Call the application's entry point.*/
bl main
bx lr
Jump_To_DFU:
ldr r0, =0x40023844 // RCC_APB2ENR
ldr r1, =0x00004000 // ENABLE SYSCFG CLOCK
str r1, [r0, #0]
ldr r0, =0x40013800 // SYSCFG_MEMRMP
ldr r1, =0x00000001 // MAP ROM AT ZERO
str r1, [r0, #0]
ldr r0, =0x1FFF0000 // ROM BASE
ldr sp, [r0, #0] // SP @ +0
ldr r0, [r0, #4] // PC @ +4
bx r0
.size Reset_Handler, .-Reset_Handler
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/