POSIX file I/O by Oliver Schmidt

git-svn-id: svn://svn.cc65.org/cc65/trunk@3457 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/apple2/read.s

@@ -1,50 +1,105 @@
 ;
-; Ullrich von Bassewitz, 30.05.1998
+; Oliver Schmidt, 12.01.2005
 ;
-; int read (int fd, void* buf, int count);
-;
-; THIS IS A HACK!
+; int __fastcall__ read (int fd, void* buf, unsigned count);
 ;
 
-   	.export	      	_read
-	.import	      	popax, _cputc, RDKEY
-	.importzp     	ptr1, ptr2, ptr3
+        .constructor	initprompt
+        .export		_read
+        .import		rwprolog, rwcommon
+        .import		errnoexit
+        .import		RDKEY, COUT
 
-_read:	jsr	popax 		; get count
-     	sta	ptr2
-     	stx	ptr2+1		; save it for later
-     	jsr	popax 		; get buf
-     	sta	ptr1
-     	stx	ptr1+1
-     	jsr	popax 		; get fd and discard it
-   	lda	#$00
-   	sta	ptr3
-   	sta	ptr3+1		; set count
+        .include	"zeropage.inc"
+        .include	"errno.inc"
+        .include	"fcntl.inc"
+        .include	"mli.inc"
+        .include	"filedes.inc"
+        .include	"apple2.inc"
 
-L1:    	lda	ptr2
-   	ora	ptr2+1		; count zero?
-   	beq	L9
-   	jsr	RDKEY
-	and	#$7F		; clear high bit.
-	pha
-	jsr	_cputc
-	pla
-	ldy	#$00		; offset into string
-   	sta	(ptr1),y	; save char
-   	inc	ptr1
-   	bne	L2
-   	inc	ptr1+1
-L2:    	inc    	ptr3  		; increment count
-	bne	L3
-	inc	ptr3+1
-L3:	cmp	#$0D 		; CR?
-	bne    	L1
+        .segment	"INIT"
 
-; Done, return the count
+initprompt:
+        ; Set prompt <> ']' to let DOS 3.3 know that we're
+        ; not in Applesoft immediate mode and thus keep it
+        ; from scanning our device I/O for DOS commands.
+        lda	#$80		; Same value used at $D52C
+        sta	PROMPT
+        rts
 
-L9:     lda	ptr3
-      	ldx	ptr3+1
-      	rts
+        .code
 
+_read:
+        ; Get parameters
+        jsr	rwprolog
+        bcs	errno
+        tax			; Save fd
 
+        ; Check for read access
+        lda	fdtab + FD::FLAGS,y
+        and	#O_RDONLY
+        beq	einval
 
+        ; Check for device
+        txa			; Restore fd
+        bmi	device
+
+        ; Do read
+        ldy	#READ_CALL
+        jmp	rwcommon
+
+        ; Set counter to zero
+device: lda	#$00
+        sta	ptr3
+        sta	ptr3+1
+
+        ; Check for zero count
+        lda	ptr2
+        ora	ptr2+1
+        beq	check
+
+        ; Read from device and echo to device
+next:   jsr	RDKEY
+        jsr	COUT
+
+        ; Clear hi bit and check for '\r'
+        and	#$7F
+        cmp	#$0D
+        bne	:+
+
+        ; Replace with '\n' and set count to zero
+        lda	#$0A
+        ldy	#$00
+        sty	ptr2
+        sty	ptr2+1
+
+        ; Put char into buf
+:       ldy	#$00
+        sta	(ptr1),y
+
+        ; Increment pointer
+        inc	ptr1
+        bne	:+
+        inc	ptr1+1
+
+        ; Increment counter
+:       inc	ptr3
+        bne	check
+        inc	ptr3+1
+
+        ; Check for counter less than count
+check:  lda	ptr3
+        cmp	ptr2
+        bcc	next
+        ldx	ptr3+1
+        cpx	ptr2+1
+        bcc	next
+
+        ; Return success, AX already set
+        rts
+
+        ; Load errno code
+einval: lda	#EINVAL
+
+        ; Return errno
+errno:  jmp	errnoexit