.intel_syntax noprefix

    .text

# String-copying routine. Strings should be null-terminated.
# Input: rdi = source string base, rsi = destination string base
# No check is done for buffer overflow.
strcpy:
    movb r10b, [rdi]
    cmpb r10b, 0
    je .end
    movb [rsi], r10b
    inc rdi
    inc rsi
    jmp strcpy
.end:
    ret