Scanf ARM Assembly

Question

I know there\'s a question here but I really don\'t understand what the OP did. I\'ve used x86 assembly before and for that you\'d do something like this:

p         


        

Answer 1

This is what ended up working for me:

sub     sp, sp, #4

@ Call scanf and store value in r4
ldr     r0, addrInp
mov     r1, sp
bl      scanf
ldr     r4, [sp]

add     sp, sp, #4

The value the user inputs ends up in r4 in this case. I don't understand why Jesters way didn't work but it just gave a segfault every time.

Answer 2

ldr should by all means work. This certainly compiles:

ldr r0, =fmtInput
ldr r1, =num
bl scanf

.data
num: .word 0
fmtInput: .string "%d"