/**
  ******************************************************************************
  * @file      startup_stm32g0b0xx.s
  * @author    MCD Application Team
  * @brief     STM32G0b0xx devices vector table GCC toolchain.
  *            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-M0+ processor is in Thread mode,
  *            priority is Privileged, and the Stack is set to Main.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2018-2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

.syntax unified
.cpu cortex-m0plus
.fpu softvfp
.thumb

.global g_pfnVectors
.global Default_Handler

/* start address for the initialization values of the .data section.
defined in linker script */
.word _sidata
/* start address for the .data section. defined in linker script */
.word _sdata
/* end address for the .data section. defined in linker script */
.word _edata
/* start address for the .bss section. defined in linker script */
.word _sbss
/* end address for the .bss section. defined in linker script */
.word _ebss

/**
 * @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
  .weak Reset_Handler
  .type Reset_Handler, %function
Reset_Handler:
  ldr   r0, =_estack
  mov   sp, r0          /* set stack pointer */

/* Call the clock system initialization function.*/
  bl  SystemInit

/* Copy the data segment initializers from flash to SRAM */
  ldr r0, =_sdata
  ldr r1, =_edata
  ldr r2, =_sidata
  movs r3, #0
  b LoopCopyDataInit

CopyDataInit:
  ldr r4, [r2, r3]
  str r4, [r0, r3]
  adds r3, r3, #4

LoopCopyDataInit:
  adds r4, r0, r3
  cmp r4, r1
  bcc CopyDataInit

/* Zero fill the bss segment. */
  ldr r2, =_sbss
  ldr r4, =_ebss
  movs r3, #0
  b LoopFillZerobss

FillZerobss:
  str  r3, [r2]
  adds r2, r2, #4

LoopFillZerobss:
  cmp r2, r4
  bcc FillZerobss

/* Call static constructors */
  bl __libc_init_array
/* Call the application s entry point.*/
  bl main

LoopForever:
  b LoopForever

.size Reset_Handler, .-Reset_Handler

/**
 * @brief  This is the code that gets called when the processor receives an
 *         unexpected interrupt.  This simply enters an infinite loop, preserving
 *         the system state for examination by a debugger.
 *
 * @param  None
 * @retval None
*/
  .section .text.Default_Handler,"ax",%progbits
Default_Handler:
Infinite_Loop:
  b Infinite_Loop
  .size Default_Handler, .-Default_Handler

/******************************************************************************
*
* The minimal vector table for a Cortex M0.  Note that the proper constructs
* must be placed on this to ensure that it ends up at physical address
* 0x0000.0000.
*
******************************************************************************/
  .section .isr_vector,"a",%progbits
  .type g_pfnVectors, %object
  .size g_pfnVectors, .-g_pfnVectors

g_pfnVectors:
  .word _estack
  .word Reset_Handler
  .word NMI_Handler
  .word HardFault_Handler
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word 0
  .word SVC_Handler
  .word 0
  .word 0
  .word PendSV_Handler
  .word SysTick_Handler
  .word WWDG_IRQHandler                   /* Window WatchDog              */
  .word  0                                /* reserved                     */
  .word RTC_TAMP_IRQHandler               /* RTC through the EXTI line    */
  .word FLASH_IRQHandler                  /* FLASH                        */
  .word RCC_IRQHandler                    /* RCC                          */
  .word EXTI0_1_IRQHandler                /* EXTI Line 0 and 1            */
  .word EXTI2_3_IRQHandler                /* EXTI Line 2 and 3            */
  .word EXTI4_15_IRQHandler               /* EXTI Line 4 to 15            */
  .word USB_IRQHandler                    /* USB                          */
  .word DMA1_Channel1_IRQHandler          /* DMA1 Channel 1               */
  .word DMA1_Channel2_3_IRQHandler        /* DMA1 Channel 2 and Channel 3 */
  .word DMA1_Ch4_7_DMA2_Ch1_5_DMAMUX1_OVR_IRQHandler /* DMA1 Ch4 to Ch7, DMA2 Ch1 to Ch5, DMAMUX1 overrun */
  .word ADC1_IRQHandler                   /* ADC1                         */
  .word TIM1_BRK_UP_TRG_COM_IRQHandler    /* TIM1 Break, Update, Trigger and Commutation */
  .word TIM1_CC_IRQHandler                /* TIM1 Capture Compare         */
  .word  0                                /* reserved                     */
  .word TIM3_TIM4_IRQHandler              /* TIM3, TIM4                   */
  .word TIM6_IRQHandler                   /* TIM6                         */
  .word TIM7_IRQHandler                   /* TIM7                         */
  .word TIM14_IRQHandler                  /* TIM14                        */
  .word TIM15_IRQHandler                  /* TIM15                        */
  .word TIM16_IRQHandler                  /* TIM16                        */
  .word TIM17_IRQHandler                  /* TIM17                        */
  .word I2C1_IRQHandler                   /* I2C1                         */
  .word I2C2_3_IRQHandler                 /* I2C2, I2C3                   */
  .word SPI1_IRQHandler                   /* SPI1                         */
  .word SPI2_3_IRQHandler                 /* SPI2, SPI3                   */
  .word USART1_IRQHandler                 /* USART1                       */
  .word USART2_IRQHandler                 /* USART2                       */
  .word USART3_4_5_6_IRQHandler           /* USART3, USART4, USART5, USART6 */

/*******************************************************************************
*
* Provide weak aliases for each Exception handler to the Default_Handler.
* As they are weak aliases, any function with the same name will override
* this definition.
*
*******************************************************************************/

  .weak      NMI_Handler
  .thumb_set NMI_Handler,Default_Handler

  .weak      HardFault_Handler
  .thumb_set HardFault_Handler,Default_Handler

  .weak      SVC_Handler
  .thumb_set SVC_Handler,Default_Handler

  .weak      PendSV_Handler
  .thumb_set PendSV_Handler,Default_Handler

  .weak      SysTick_Handler
  .thumb_set SysTick_Handler,Default_Handler

  .weak      WWDG_IRQHandler
  .thumb_set WWDG_IRQHandler,Default_Handler

  .weak      RTC_TAMP_IRQHandler
  .thumb_set RTC_TAMP_IRQHandler,Default_Handler

  .weak      FLASH_IRQHandler
  .thumb_set FLASH_IRQHandler,Default_Handler

  .weak      RCC_IRQHandler
  .thumb_set RCC_IRQHandler,Default_Handler

  .weak      EXTI0_1_IRQHandler
  .thumb_set EXTI0_1_IRQHandler,Default_Handler

  .weak      EXTI2_3_IRQHandler
  .thumb_set EXTI2_3_IRQHandler,Default_Handler

  .weak      EXTI4_15_IRQHandler
  .thumb_set EXTI4_15_IRQHandler,Default_Handler

  .weak      USB_IRQHandler
  .thumb_set USB_IRQHandler,Default_Handler

  .weak      DMA1_Channel1_IRQHandler
  .thumb_set DMA1_Channel1_IRQHandler,Default_Handler

  .weak      DMA1_Channel2_3_IRQHandler
  .thumb_set DMA1_Channel2_3_IRQHandler,Default_Handler

  .weak      DMA1_Ch4_7_DMA2_Ch1_5_DMAMUX1_OVR_IRQHandler
  .thumb_set DMA1_Ch4_7_DMA2_Ch1_5_DMAMUX1_OVR_IRQHandler,Default_Handler

  .weak      ADC1_IRQHandler
  .thumb_set ADC1_IRQHandler,Default_Handler

  .weak      TIM1_BRK_UP_TRG_COM_IRQHandler
  .thumb_set TIM1_BRK_UP_TRG_COM_IRQHandler,Default_Handler

  .weak      TIM1_CC_IRQHandler
  .thumb_set TIM1_CC_IRQHandler,Default_Handler

  .weak      TIM3_TIM4_IRQHandler
  .thumb_set TIM3_TIM4_IRQHandler,Default_Handler

  .weak      TIM6_IRQHandler
  .thumb_set TIM6_IRQHandler,Default_Handler

  .weak      TIM7_IRQHandler
  .thumb_set TIM7_IRQHandler,Default_Handler

  .weak      TIM14_IRQHandler
  .thumb_set TIM14_IRQHandler,Default_Handler

  .weak      TIM15_IRQHandler
  .thumb_set TIM15_IRQHandler,Default_Handler

  .weak      TIM16_IRQHandler
  .thumb_set TIM16_IRQHandler,Default_Handler

  .weak      TIM17_IRQHandler
  .thumb_set TIM17_IRQHandler,Default_Handler

  .weak      I2C1_IRQHandler
  .thumb_set I2C1_IRQHandler,Default_Handler

  .weak      I2C2_3_IRQHandler
  .thumb_set I2C2_3_IRQHandler,Default_Handler

  .weak      SPI1_IRQHandler
  .thumb_set SPI1_IRQHandler,Default_Handler

  .weak      SPI2_3_IRQHandler
  .thumb_set SPI2_3_IRQHandler,Default_Handler

  .weak      USART1_IRQHandler
  .thumb_set USART1_IRQHandler,Default_Handler

  .weak      USART2_IRQHandler
  .thumb_set USART2_IRQHandler,Default_Handler

  .weak      USART3_4_5_6_IRQHandler
  .thumb_set USART3_4_5_6_IRQHandler,Default_Handler