.text .code 16 .global call_into_middle_of_titlescreen_func .thumb_func call_into_middle_of_titlescreen_func: push {lr} push {r4-r5} @ use r4 (which already got saved to the stack) as scratch space to reserve a variable amount of stack space mov r4,sp sub r4,r4,r1 mov sp,r4 bx r0