LEA EmptyString,A0 ;assign the empty string to address register A0

getStringLength:
MOVE.L A0,-(SP)    ;push A0 onto the stack. This will be used to check if the string is empty.

loop_getStringLength:
MOVE.B (A0)+,D0
BEQ Terminated
JMP loop_getStringLength

SUBQ.L #1,A0      ;after the terminator is read, A0 is incremented to point to the byte after it. This fixes that.
CMP.L A0,(SP)     ;compare the current A0 with the original value.
BEQ StringIsEmpty ;if they are equal, then nothing was read besides the terminator. Therefore the string is empty.
;if the above branch wasn't taken, the string is not empty and execution arrives here.