static FOO: u64 = 0x00000004;

unsafe fn jmp(addr: *const core::ffi::c_void) {
    asm!("ldr %0, %1" : "=r"(addr) : "0"(addr));
    asm!("br %0" : : "0"(addr));
}

fn main() {
    println!("{:?}", FOO as *const core::ffi::c_void);
    unsafe {
        jmp(FOO as *const core::ffi::c_void);
    }
}