mirror of
https://github.com/cc65/cc65.git
synced 2024-08-19 17:29:37 +00:00
252 lines
7.8 KiB
Plaintext
252 lines
7.8 KiB
Plaintext
|
<!doctype linuxdoc system>
|
||
|
|
||
|
<article>
|
||
|
|
||
|
<title>cc65 Library Overview
|
||
|
<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
|
||
|
<date>02.12.2000
|
||
|
|
||
|
<abstract>
|
||
|
An overview over the runtime and C libraries that come with the cc65 compiler,
|
||
|
including a discussion of the differences to the ISO standard.
|
||
|
</abstract>
|
||
|
|
||
|
<!-- Table of contents -->
|
||
|
<toc>
|
||
|
|
||
|
<!-- Begin the document -->
|
||
|
|
||
|
<sect>Overview<p>
|
||
|
|
||
|
This file contains a description of the library routines available for the
|
||
|
cc65 C compiler. It is not complete in some areas, so if you miss something,
|
||
|
have a look into the header files. All functions, that are not defined by the
|
||
|
ISO C standard have a short comment in the headers, explaining their use.
|
||
|
|
||
|
|
||
|
|
||
|
<sect>ISO C compatible library<p>
|
||
|
|
||
|
The C library contains a large subset of the ISO C library. Functions are
|
||
|
usually missing in areas, where there is no support on typical 6502 systems.
|
||
|
Wide character sets are an example for this.
|
||
|
|
||
|
I will not go into detail about the ISO functions. If a function is not
|
||
|
mentioned here explicitly, expect it to be available and to behave as defined
|
||
|
in the C standard.
|
||
|
|
||
|
Functions that are NOT available:
|
||
|
|
||
|
<itemize>
|
||
|
|
||
|
<item>ftell/fseek/fgetpos/fsetpos
|
||
|
|
||
|
<item>tmpfile/tmpnam
|
||
|
|
||
|
<item>The scanf family of functions
|
||
|
|
||
|
<item>time/asctime/ctime/difftime/asctime/gmtime/localtime/mktime/strftime
|
||
|
|
||
|
<item>system
|
||
|
|
||
|
<item>All functions that handle floating point numbers in some manner.
|
||
|
|
||
|
<item>The div and ldiv functions (because cc65 is not able to return
|
||
|
structs).
|
||
|
|
||
|
<item>All functions handling wide character strings.
|
||
|
|
||
|
<item>Signals and all related functions (having SIGSEGV would be cool:-)
|
||
|
|
||
|
<item>rename/remove/rewind
|
||
|
|
||
|
<item>setbuf/setvbuf/ungetc
|
||
|
|
||
|
</itemize>
|
||
|
|
||
|
Functions that are limited in any way:
|
||
|
|
||
|
<itemize>
|
||
|
|
||
|
<item>fopen/fread/fwrite/fclose/fputs/fgets/fscanf....
|
||
|
|
||
|
These functions are built on open/read/write/close. Neither of these low
|
||
|
level functions is currently available for the supported systems, and so,
|
||
|
fopen and friends do not work. However, the functions exist and are tested
|
||
|
to some degree under the ACE operating systems (which is no longer
|
||
|
supported).
|
||
|
|
||
|
|
||
|
<item>The va_... family of macros
|
||
|
|
||
|
The macros do not work completely as defined by the standard. Since cc65 has
|
||
|
the wrong calling order, the (non-standard) va_fix macro must be used to
|
||
|
access fixed parameters in functions with a variable parameter size. See
|
||
|
newvers.txt for a discussion of the problem.
|
||
|
|
||
|
<item>strcspn/strpbrk/strspn
|
||
|
|
||
|
These functions have a length limitation of 256 for the second string
|
||
|
argument. Since this string gives a character set, and there are only 256
|
||
|
distinct characters, this shouldn't be a problem.
|
||
|
|
||
|
<item>getenv
|
||
|
|
||
|
Since there is no such thing as an environment on all supported systems, the
|
||
|
getenv function will always return a NULL pointer.
|
||
|
|
||
|
|
||
|
<item>locale
|
||
|
|
||
|
There is no other locale than the "C" locale. The native locale is identical
|
||
|
to the "C" locale.
|
||
|
|
||
|
</itemize>
|
||
|
|
||
|
|
||
|
In addition to these limitations, some more functions are limited if inlined
|
||
|
versions are requested by using -Os:
|
||
|
|
||
|
<itemize>
|
||
|
|
||
|
<item>The strlen function only works for strings with a maximum length of
|
||
|
255 characters.
|
||
|
|
||
|
<item>The isxxx character classification functions from <tt/<ctype.h>/
|
||
|
will give unpredictable results if the argument is not in character range
|
||
|
(0..255). This limitation may be removed by #undef'ing the function name
|
||
|
(when using -Os, the functions are actually macros that expand to inline
|
||
|
assembler code, but the real functions are still available if the macro
|
||
|
definition is removed).
|
||
|
|
||
|
</itemize>
|
||
|
|
||
|
|
||
|
|
||
|
<sect>CPU specific stuff - 6502.h<p>
|
||
|
|
||
|
The header file 6502.h contains some functions that make only sense with the
|
||
|
6502 CPU. Examples are macros to insert more or less useful instructions into
|
||
|
your C code, or a function to call arbitrary machine language subroutines,
|
||
|
passing registers in and out.
|
||
|
|
||
|
|
||
|
|
||
|
<sect>Target specific stuff<p>
|
||
|
|
||
|
For each supported system there's a header file that contains calls or defines
|
||
|
specific for this system. So, when programming for the C64, include c64.h, for
|
||
|
the C128, include c128.h and so on. To make the task for the Commodore systems
|
||
|
easier, there is also a header file named cbm.h that will define stuff common
|
||
|
for all CBM systems, and include the header file for the specific target
|
||
|
system.
|
||
|
|
||
|
The header files contain
|
||
|
|
||
|
<itemize>
|
||
|
|
||
|
<item>Defines for special keys (like function keys)
|
||
|
|
||
|
<item>Defines for special characters (like the graphics characters)
|
||
|
|
||
|
<item>Variables with a fixed address in memory that may be used to access
|
||
|
special hardware. For the C64 and C128 there is a variable struct named
|
||
|
<tt/SID/. Writing to the fields of this struct will write to the SID device
|
||
|
instead. Using these variables will make your program more readable and more
|
||
|
portable. Don't fear ineffective code when using these variables, the
|
||
|
compiler will translate reads and writes to these structs into direct memory
|
||
|
accesses.
|
||
|
|
||
|
<item>Other routines that make only sense for a specific system. One example
|
||
|
are routines to write memory locations in the system bank for the CBM
|
||
|
600/700 family (called B128/B256 in the US).
|
||
|
|
||
|
</itemize>
|
||
|
|
||
|
|
||
|
<sect>Direct console I/O - <tt/conio.h/<p>
|
||
|
|
||
|
The <tt/conio.h/ header file contains a large set of functions that do screen
|
||
|
and keyboard I/O. The functions will write directly to the screen or poll the
|
||
|
keyboard directly with no more help from the operating system than needed.
|
||
|
This has some disadvantages, but on the other side it's fast and reasonably
|
||
|
portable. conio implementations exist for the following targets:
|
||
|
|
||
|
<itemize>
|
||
|
<item>atari
|
||
|
<item>c64
|
||
|
<item>c128
|
||
|
<item>plus4
|
||
|
<item>cbm610 (all CBM series-II computers with 80 column video)
|
||
|
<item>pet (all CBM PET systems except the 2001)
|
||
|
<item>apple2
|
||
|
</itemize>
|
||
|
|
||
|
The conio.h header file does also include the system specific header files
|
||
|
which define constants for special characters and keys.
|
||
|
|
||
|
|
||
|
|
||
|
<sect>Using the joystick - <tt/joystick.h/<p>
|
||
|
|
||
|
For systems that have a joystick, <tt/joystick.h/ will define a subroutine to
|
||
|
read the current value, including constants to evaluate the result of this
|
||
|
function. To help in writing portable code, the header file will define the
|
||
|
symbol <tt/__JOYSTICK__/ on systems that have a joystick.
|
||
|
|
||
|
|
||
|
|
||
|
<sect>Using a mouse - <tt/mouse.h/<p>
|
||
|
|
||
|
Some target machines support a mouse. Mouse support is currently in beta and
|
||
|
available for the following targets:
|
||
|
|
||
|
<itemize>
|
||
|
<item>atari
|
||
|
<item>c64
|
||
|
</itemize>
|
||
|
|
||
|
The available functions are declared in <tt/mouse.h/ To help writing portable
|
||
|
code, the header file will define the symbol <tt/__MOUSE__/ in systems that
|
||
|
support a mouse.
|
||
|
|
||
|
|
||
|
<sect>Bugs/Feedback<p>
|
||
|
|
||
|
If you have problems using the library, if you find any bugs, or if you're
|
||
|
doing something interesting with it, I would be glad to hear from you. Feel
|
||
|
free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
|
||
|
name="uz@cc65.org">).
|
||
|
|
||
|
|
||
|
|
||
|
<sect>Copyright<p>
|
||
|
|
||
|
This C runtime library implementation for the cc65 compiler is (C)
|
||
|
Copyright 1998-1999 Ullrich von Bassewitz. For usage of the binaries
|
||
|
and/or sources the following conditions do apply:
|
||
|
|
||
|
This software is provided 'as-is', without any expressed or implied
|
||
|
warranty. In no event will the authors be held liable for any damages
|
||
|
arising from the use of this software.
|
||
|
|
||
|
Permission is granted to anyone to use this software for any purpose,
|
||
|
including commercial applications, and to alter it and redistribute it
|
||
|
freely, subject to the following restrictions:
|
||
|
|
||
|
<enum>
|
||
|
<item> The origin of this software must not be misrepresented; you must not
|
||
|
claim that you wrote the original software. If you use this software
|
||
|
in a product, an acknowledgment in the product documentation would be
|
||
|
appreciated but is not required.
|
||
|
<item> Altered source versions must be plainly marked as such, and must not
|
||
|
be misrepresented as being the original software.
|
||
|
<item> This notice may not be removed or altered from any source
|
||
|
distribution.
|
||
|
</enum>
|
||
|
|
||
|
</article>
|
||
|
|
||
|
|
||
|
|