5.125 · exercise

Fill in the blank: strings

Fill in the missing piece of code that stores, walks, and changes a string one byte at a time.

0 of 6 correct

Fill in the blank

Store the word yes with no zero byte after it, as a piece that the next string in .data finishes.

part_m: . "yes"

Fill in the blank

Load the byte at the address in x9 into w10, with the rest of w10 set to zero.

w10, [x9]

Fill in the blank

Store the low byte of w10 at the address in x9, then move x9 on to the next byte.

w10, [x9], 1

Fill in the blank

w10 holds the byte that ldrb just loaded from the string. Compare it so that the b.eq walk_done after this line leaves the loop at the byte that ends the string.

cmp w10,

Fill in the blank

Turn the lower-case letter in w10 into its capital.

sub w10, w10,

Fill in the blank

Load entry 3 of the table of string addresses whose base is in x20.

ldr x21, [x20, ]