;this example uses VASM syntax which considers a "word" to be 16-bit regardless of the architecture
InitStackPointer:    .long 0x3FFFFFFF   ;other assemblers would call this a "word"

MOV R1,#InitStackPointer
LDR SP,[R1]  ;set up the stack pointer
LDR R2,[R1]  ;also load it into R2
;There's no point in checking since we haven't pushed/popped anything but just for demonstration purposes we'll check now
CMP SP,R2
BEQ StackIsEmpty