minix/lib/i86/string/_strncpy.s
2009-11-09 10:26:00 +00:00

21 lines
537 B
ArmAsm

! _strncpy() Author: Kees J. Bot
! 27 Jan 1994
.sect .text; .sect .rom; .sect .data; .sect .bss
! char *_strncpy(char *s1, const char *s2, size_t cx)
! Copy string s2 to s1.
!
.sect .text
.define __strncpy
__strncpy:
mov di, 6(bp) ! di = string s2
xorb al, al ! Look for a zero byte
mov dx, cx ! Save maximum count
cld
repne scasb ! Look for end of s2
sub dx, cx ! Number of bytes in s2 including null
xchg cx, dx
mov si, 6(bp) ! si = string s2
mov di, 4(bp) ! di = string s1
rep movsb ! Copy bytes
ret