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;
; Ullrich von Bassewitz, 17.07.2002
;
; const char* __fastcall__ _stroserror (unsigned char errcode);
; /* Map an operating system error number to an error message. */
;
.export __stroserror
.import __sys_oserrlist
.importzp ptr1, tmp1
.macpack generic
; The table is built as a list of entries
;
; .byte entrylen
; .byte errorcode
; .asciiz errormsg
;
; and terminated by an entry with length zero that is returned if the
; error code could not be found.
__stroserror:
sta tmp1 ; Save the error code
ldy #<__sys_oserrlist
sty ptr1
ldy #>__sys_oserrlist
sty ptr1+1 ; Setup pointer to message table
@L1: ldy #0
lda (ptr1),y ; Get the length
beq Done ; Bail out if end of list reached
iny
lda (ptr1),y ; Compare the error code
cmp tmp1
beq Done ; Jump if found
; Not found, move pointer to next entry
dey
clc
lda ptr1
adc (ptr1),y
sta ptr1
bcc @L1
inc ptr1+1
bcs @L1 ; Branch always
; We've found the code or reached the end of the list
Done: ldx ptr1+1
lda ptr1
add #2 ; Add a total of #2
bcc @L1
inx ; Bump high byte
@L1: rts
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