pico_hello_world.s

.syntax unified                     
.thumb_func                         
.global main                        

main:
init:   bl stdio_init_all           

loop:   
        ldr r0, DELAY_TIME_MS       // Set the delay period
        bl sleep_ms                 // Delay for the specified time

        ldr r0, =TEXT0              // Set the printf string
        bl printf

        b loop                      // Loop forever


/*
 Use four-bytes to store the delay time so that we can load
 into r0 a 32-bit value, rather than move in an 8-bit value
 */
.align 4
DELAY_TIME_MS:  .word           500
TEXT0:          .asciz          "Hello World\n"