.syntax unified
.cpu cortex-m4
.thumb

.section .data
    test_string: .asciz "Hello"

.section .text

lab1_v2:
    sub sp, #6
    ldr r0, =test_string
    mov r1, #5

    copy_loop:
    ldrb r2, [r0, r1]
    strb r2, [sp, r1]
    subs r1, #1
    bpl copy_loop

    mov r1, sp
    mov r0, 0x04
    bkpt 0xAB

    add sp, #6

    mov pc, lr