1 <!doctype linuxdoc system>
5 <title>cc65 Library Overview
6 <author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
10 An overview over the runtime and C libraries that come with the cc65 compiler,
11 including a discussion of the differences to the ISO standard.
14 <!-- Table of contents -->
17 <!-- Begin the document -->
21 This file contains a description of the library routines available for the
22 cc65 C compiler. It is not complete in some areas, so if you miss something,
23 have a look into the header files. All functions, that are not defined by the
24 ISO C standard have a short comment in the headers, explaining their use.
28 <sect>ISO C compatible library<p>
30 The C library contains a large subset of the ISO C library. Functions are
31 usually missing in areas, where there is no support on typical 6502 systems.
32 Wide character sets are an example for this.
34 I will not go into detail about the ISO functions. If a function is not
35 mentioned here explicitly, expect it to be available and to behave as defined
38 Functions that are NOT available:
42 <item>ftell/fseek/fgetpos/fsetpos
46 <item>The scanf family of functions
48 <item>time/asctime/ctime/difftime/asctime/gmtime/localtime/mktime/strftime
52 <item>All functions that handle floating point numbers in some manner.
54 <item>The div and ldiv functions (because cc65 is not able to return
57 <item>All functions handling wide character strings.
59 <item>Signals and all related functions (having SIGSEGV would be cool:-)
61 <item>rename/remove/rewind
63 <item>setbuf/setvbuf/ungetc
67 Functions that are limited in any way:
71 <item>fopen/fread/fwrite/fclose/fputs/fgets/fscanf....
73 These functions are built on open/read/write/close. Neither of these low
74 level functions is currently available for the supported systems, and so,
75 fopen and friends do not work. However, the functions exist and are tested
76 to some degree under the ACE operating systems (which is no longer
80 <item>The va_... family of macros
82 The macros do not work completely as defined by the standard. Since cc65 has
83 the wrong calling order, the (non-standard) va_fix macro must be used to
84 access fixed parameters in functions with a variable parameter size. See
85 newvers.txt for a discussion of the problem.
87 <item>strcspn/strpbrk/strspn
89 These functions have a length limitation of 256 for the second string
90 argument. Since this string gives a character set, and there are only 256
91 distinct characters, this shouldn't be a problem.
95 Since there is no such thing as an environment on all supported systems, the
96 getenv function will always return a NULL pointer.
101 There is no other locale than the "C" locale. The native locale is identical
107 In addition to these limitations, some more functions are limited if inlined
108 versions are requested by using -Os:
112 <item>The strlen function only works for strings with a maximum length of
115 <item>The isxxx character classification functions from <tt/<ctype.h>/
116 will give unpredictable results if the argument is not in character range
117 (0..255). This limitation may be removed by #undef'ing the function name
118 (when using -Os, the functions are actually macros that expand to inline
119 assembler code, but the real functions are still available if the macro
120 definition is removed).
126 <sect>CPU specific stuff - 6502.h<p>
128 The header file 6502.h contains some functions that make only sense with the
129 6502 CPU. Examples are macros to insert more or less useful instructions into
130 your C code, or a function to call arbitrary machine language subroutines,
131 passing registers in and out.
135 <sect>Target specific stuff<p>
137 For each supported system there's a header file that contains calls or defines
138 specific for this system. So, when programming for the C64, include c64.h, for
139 the C128, include c128.h and so on. To make the task for the Commodore systems
140 easier, there is also a header file named cbm.h that will define stuff common
141 for all CBM systems, and include the header file for the specific target
144 The header files contain
148 <item>Defines for special keys (like function keys)
150 <item>Defines for special characters (like the graphics characters)
152 <item>Variables with a fixed address in memory that may be used to access
153 special hardware. For the C64 and C128 there is a variable struct named
154 <tt/SID/. Writing to the fields of this struct will write to the SID device
155 instead. Using these variables will make your program more readable and more
156 portable. Don't fear ineffective code when using these variables, the
157 compiler will translate reads and writes to these structs into direct memory
160 <item>Other routines that make only sense for a specific system. One example
161 are routines to write memory locations in the system bank for the CBM
162 600/700 family (called B128/B256 in the US).
167 <sect>Direct console I/O - <tt/conio.h/<p>
169 The <tt/conio.h/ header file contains a large set of functions that do screen
170 and keyboard I/O. The functions will write directly to the screen or poll the
171 keyboard directly with no more help from the operating system than needed.
172 This has some disadvantages, but on the other side it's fast and reasonably
173 portable. conio implementations exist for the following targets:
180 <item>cbm610 (all CBM series-II computers with 80 column video)
181 <item>pet (all CBM PET systems except the 2001)
185 The conio.h header file does also include the system specific header files
186 which define constants for special characters and keys.
190 <sect>Using the joystick - <tt/joystick.h/<p>
192 For systems that have a joystick, <tt/joystick.h/ will define a subroutine to
193 read the current value, including constants to evaluate the result of this
194 function. To help in writing portable code, the header file will define the
195 symbol <tt/__JOYSTICK__/ on systems that have a joystick.
199 <sect>Using a mouse - <tt/mouse.h/<p>
201 Some target machines support a mouse. Mouse support is currently in beta and
202 available for the following targets:
209 The available functions are declared in <tt/mouse.h/ To help writing portable
210 code, the header file will define the symbol <tt/__MOUSE__/ in systems that
214 <sect>Bugs/Feedback<p>
216 If you have problems using the library, if you find any bugs, or if you're
217 doing something interesting with it, I would be glad to hear from you. Feel
218 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
219 name="uz@cc65.org">).
225 This C runtime library implementation for the cc65 compiler is (C)
226 Copyright 1998-1999 Ullrich von Bassewitz. For usage of the binaries
227 and/or sources the following conditions do apply:
229 This software is provided 'as-is', without any expressed or implied
230 warranty. In no event will the authors be held liable for any damages
231 arising from the use of this software.
233 Permission is granted to anyone to use this software for any purpose,
234 including commercial applications, and to alter it and redistribute it
235 freely, subject to the following restrictions:
238 <item> The origin of this software must not be misrepresented; you must not
239 claim that you wrote the original software. If you use this software
240 in a product, an acknowledgment in the product documentation would be
241 appreciated but is not required.
242 <item> Altered source versions must be plainly marked as such, and must not
243 be misrepresented as being the original software.
244 <item> This notice may not be removed or altered from any source