.syntax unified
.cpu cortex-m4
.thumb

.equ SYSTICK_OFFSET, 0xE000E010

.section .text

vtable:
    .word __stack_start
    .word __hard_reset__+1
v2_img_start:
    .incbin "lab1_v2.bin"
v2_img_end: @ ==__hard_reset__

__hard_reset__:
    bl load_systick_timer
    bl lab1_v1

    bl bootload_v2


    readloop:
    ldr.n r0, [r7, #8]
    b.n readloop

load_systick_timer:
    @ SysTick_LOAD
    ldr.n r7, =SYSTICK_OFFSET
    mov r1, #0x1
    lsl r1, #20
    str.n r1, [r7, #4]

    @ SysTick_CTRL
    mov r1, #0x1
    str.n r1, [r7]

    mov pc, lr

bootload_v2:
    push {lr}

    @ bootload to ram
    ldr.n r0, =v2_img_start
    ldr.n r1, =v2_img_end
    ldr.n r3, =__ram_start

    copy_loop:
    ldrh r2, [r0], #2
    strh r2, [r3], #2
    cmp.n r0, r1
    bne.n copy_loop

    ldr.n r3, =__ram_start
    add r3, r3, #1
    blx r3

    pop {pc}