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cc65/libsrc/atari/ucase_fn.s
Christian Groessler 27841c7b40 Some Atari runtime library fixes.
* libsrc/atari/ucase_fn.s: Fix handling if input parameter 'tmp2' is 0.
* libsrc/atari/open.s: Set 'tmp2' parameter for 'ucase_fn' if DEFAULT_DEVICE
  is not defined.
2016-06-06 22:45:20 +02:00

109 lines
3.2 KiB
ArmAsm

;
; Christian Groessler, Dec-2001
;
; ucase_fn
; helper routine to convert a string (file name) to uppercase
; used by open.s and remove.s
;
; Calling parameters:
; AX - points to filename
; tmp2 - 0/$80 for don't/do prepend default device if no device
; is present in the passed string (only .ifdef DEFAULT_DEVICE)
; Return parameters:
; C - 0/1 for OK/Error (filename too long)
; AX - points to uppercased version of the filename on the stack
; tmp3 - amount of bytes used on the stack (needed for cleanup)
; Uses:
; ptr4 - scratch pointer used to remember original AX pointer
;
;
.include "atari.inc"
.ifdef DEFAULT_DEVICE
.importzp tmp2
.import __defdev
.endif
.importzp tmp3,ptr4,sp
.import subysp,addysp
.export ucase_fn
.proc ucase_fn
; we make sure that the filename doesn't contain lowercase letters
; we copy the filename we got onto the stack, uppercase it and use this
; one to open the iocb
; we're using tmp3, ptr4
; save the original pointer
sta ptr4
stx ptr4+1
.ifdef DEFAULT_DEVICE
lda tmp2
beq hasdev ; don't fiddle with device part
; bit #0 of tmp2 is used as an additional flag whether device name is present in passed string (1 = present, 0 = not present)
ldy #1
inc tmp2 ; initialize flag: device present
lda #':'
cmp (ptr4),y
beq hasdev
iny
cmp (ptr4),y
beq hasdev
dec tmp2 ; set flag: no device in passed string
hasdev:
.endif
ldy #128
sty tmp3 ; save size
jsr subysp ; make room on the stack
; copy filename to the temp. place on the stack, while uppercasing it
ldy #0
loop2: lda (ptr4),y
sta (sp),y
beq copy_end
bmi L1 ; Not lowercase (also, invalid, should reject)
cmp #'a'
bcc L1 ; Not lowercase
and #$DF ; make upper case char, assume ASCII chars
sta (sp),y ; store back
L1:
iny
bpl loop2 ; bpl: this way we only support a max. length of 127
; Filename too long
jsr addysp ; restore the stack
sec ; indicate error
rts
copy_end:
.ifdef DEFAULT_DEVICE
lda #1
bit tmp2 ; is a device present in the string?
bne hasdev2 ; yes, don't prepend something
bpl hasdev2 ; check input parameter (tmp2 != $80)
ldy #128+3 ; no, prepend "Dn:" (__defdev)
sty tmp3 ; adjust stack size used
ldy #3
jsr subysp ; adjust stack pointer
dey
cpdev: lda __defdev,y
sta (sp),y ; insert device name, number and ':'
dey
bpl cpdev
hasdev2:
.endif
; leave A and X pointing to the modified filename
lda sp
ldx sp+1
clc ; indicate success
rts
.endproc