1
0
mirror of https://github.com/cc65/cc65.git synced 2024-11-14 05:05:45 +00:00
cc65/libsrc/common/strerror.s

36 lines
886 B
ArmAsm

;
; Ullrich von Bassewitz, 17.05.2000
;
; char* __fastcall__ strerror (int errcode);
; /* Map an error number to an error message */
;
.export _strerror
.import __sys_errlist
.include "errno.inc"
_strerror:
cpx #$00 ; High byte must be zero
bne @L1 ; Jump if invalid error
cmp #EMAX ; Valid error code (map EUNKNOWN to 0)?
bcc @L2 ; Jump if ok
; The given error code is invalid
@L1: lda #<EINVAL
sta __errno
lda #>EINVAL ; = 0
sta __errno+1
; lda #$00 ; A contains zero: "Unknown error"
; Load the pointer to the error message and return
@L2: asl a ; * 2
tay
ldx __sys_errlist+1,y
lda __sys_errlist,y
rts