I'm new to using any kind of hardware. Currently I'm trying to get an interrupt to work using ARM code. However, once the interrupt starts it will keep looping through it and not stop. I think it's because I didn't clear the interrupt flag but I don't know how. I have tried everything and looked for everything for a week but nothing is changing.

Here is the code:

#include "hardware/regs/addressmap.h"
#include "hardware/regs/io_bank0.h"
#include "hardware/regs/timer.h"
#include "hardware/regs/m0plus.h"
  
  
  .syntax unified
  .cpu cortex-m0plus
  .thumb
  .global main_asm
  .align 4


  .equ GPIO_BTN_MSK, 0x00040000
  .equ GPIO_BTN, 20

  .equ GPIO_LED, 25

  .equ GPIO_DIR_IN, 0
  .equ GPIO_DIR_OUT, 1

  .equ GPIO_ISR_OFFSET, 0x74



main_asm:
  bl install_btns
  bl install_gpio_isr
  bl install_leds

loop:
  bl btn_released
  b loop


install_btns:
  push {lr}

  movs r0, #GPIO_BTN
  bl asm_gpio_set_irq
  movs r0, #GPIO_BTN
  movs r1, #GPIO_DIR_IN
  bl asm_gpio_set_dir

  pop {pc}


install_leds:
  push {lr}

  movs r0, GPIO_LED 
  bl asm_gpio_init
  movs r0, #GPIO_LED
  movs r1, #GPIO_DIR_OUT
  bl asm_gpio_set_dir

  pop {pc}



install_gpio_isr:

  ldr r2, =(PPB_BASE + M0PLUS_VTOR_OFFSET)
  ldr r1, [r2]
  ldr r2, =GPIO_ISR_OFFSET
  add r2, r1
  ldr r0, =gpio_isr

  str r0, [r2]

  ldr r0, =0x1
  lsls r0, #13
  ldr r1, =(PPB_BASE + M0PLUS_NVIC_ICPR_OFFSET)
  str r0, [r1]

  ldr r1, =(PPB_BASE + M0PLUS_NVIC_ISER_OFFSET)
  str r0, [r1]

  bx lr



.thumb_func
gpio_isr:
  push {lr}

  ldr r2, =(IO_BANK0_BASE + IO_BANK0_PROC0_INTS2_OFFSET)
  ldr r1, [r2]
  ldr r3, =GPIO_BTN_MSK
  ands r1, r3
  cmp r1, r3
  bne not_btn
btn:
  bl btn_pushed 
  b end_interrupt
not_btn:
  Bl btn_released

end_interrupt:
  
  ldr r0, =0x1
  lsls r0, #20  
  ldr r1, =(IO_BANK0_BASE + IO_BANK0_INTR2_OFFSET)
  str r0, [r1] 

  pop {pc}

.align 4

.data