1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
;
; Ullrich von Bassewitz, 16.11.2002
;
; int open (const char* name, int flags, ...); /* May take a mode argument */
.export _open
.destructor closeallfiles, 5
.import addysp, popax
.import scratch, fnparse, fnaddmode, fncomplete, fnset
.import opencmdchannel, closecmdchannel, readdiskerror
.import fnunit, fnisfile
.import _close
.importzp sp, tmp2, tmp3
.include "errno.inc"
.include "fcntl.inc"
.include "filedes.inc"
.include "cbm.inc"
;--------------------------------------------------------------------------
; closeallfiles: Close all open files.
.proc closeallfiles
ldx #MAX_FDS-1
loop: lda fdtab,x
beq next ; Skip unused entries
; Close this file
txa
pha ; Save current value of X
ldx #0
jsr _close
pla
tax
; Next file
next: dex
bpl loop
rts
.endproc
;--------------------------------------------------------------------------
; _open
.proc _open
; Throw away any additional parameters passed through the ellipsis
dey ; Parm count < 4 shouldn't be needed to be...
dey ; ...checked (it generates a c compiler warning)
dey
dey
beq parmok ; Branch if parameter count ok
jsr addysp ; Fix stack, throw away unused parameters
; Parameters ok. Pop the flags and save them into tmp3
parmok: jsr popax ; Get flags
sta tmp3
; Get the filename from stack and parse it. Bail out if is not ok
jsr popax ; Get name
jsr fnparse ; Parse it
tax
bne oserror ; Bail out if problem with name
; Get a free file handle and remember it in tmp2
jsr freefd
lda #EMFILE ; Load error code
bcs seterrno ; Jump in case of errors
stx tmp2
; Check the flags. We cannot have both, read and write flags set, and we cannot
; open a file for writing without creating it.
lda tmp3
and #(O_RDWR | O_CREAT)
cmp #O_RDONLY ; Open for reading?
beq doread ; Yes: Branch
cmp #(O_WRONLY | O_CREAT) ; Open for writing?
beq dowrite
; Invalid open mode
lda #EINVAL
; Error entry. Sets _errno, clears _oserror, returns -1
seterrno:
jmp __directerrno
; Error entry: Close the file and exit. OS error code is in A on entry
closeandexit:
pha
lda tmp2
clc
adc #LFN_OFFS
jsr CLOSE
ldx fnunit
jsr closecmdchannel
pla
; Error entry: Set oserror and errno using error code in A and return -1
oserror:jmp __mappederrno
; Read bit is set. Add an 'r' to the name
doread: lda #'r'
jsr fnaddmode ; Add the mode to the name
lda #LFN_READ
bne common ; Branch always
; If O_TRUNC is set, scratch the file, but ignore any errors
dowrite:
lda tmp3
and #O_TRUNC
beq notrunc
jsr scratch
; Complete the the file name. Check for append mode here.
notrunc:
lda tmp3 ; Get the mode again
and #O_APPEND ; Append mode?
bne append ; Branch if yes
; Setup the name for create mode
lda #'w'
jsr fncomplete ; Add type and mode to the name
jmp appendcreate
; Append bit is set. Add an 'a' to the name
append: lda #'a'
jsr fnaddmode ; Add open mode to file name
appendcreate:
lda #LFN_WRITE
; Common read/write code. Flags in A, handle in tmp2
common: sta tmp3
jsr fnset ; Set the file name
lda tmp2
clc
adc #LFN_OFFS
ldx fnunit
ldy fnisfile ; Is this a standard file on disk?
beq nofile ; Branch if not
tay ; Use the LFN also as SA for files
nofile: ; ... else use SA=0 (read)
jsr SETLFS ; Set the file params
jsr OPEN
bcs oserror
; Open the the drive command channel and read it
ldx fnunit
jsr opencmdchannel
bne closeandexit
ldx fnunit
jsr readdiskerror
bne closeandexit ; Branch on error
; File is open. Mark it as open in the table
ldx tmp2
lda tmp3
sta fdtab,x
lda fnunit
sta unittab,x ; Remember
; Done. Return the handle in a/x
txa ; Handle
ldx #0
stx __oserror ; Clear _oserror
rts
.endproc
|
