mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 04:30:10 +00:00
240 lines
7.3 KiB
Plaintext
240 lines
7.3 KiB
Plaintext
|
|
|
|
Description of the C library for the cc65 C compiler
|
|
|
|
(C) Copyright 1998-1999 Ullrich von Bassewitz
|
|
(uz@musoftware.de)
|
|
|
|
|
|
|
|
Contents
|
|
--------
|
|
|
|
1. Overview
|
|
|
|
2. ISO C compatible library
|
|
|
|
3. CPU specific stuff - 6502.h
|
|
|
|
4. System specific stuff
|
|
|
|
5. Direct console I/O - conio.h
|
|
|
|
6. Using the joystick - joystick.h
|
|
|
|
7. Bugs/Feedback
|
|
|
|
8. Copyright
|
|
|
|
|
|
|
|
1. Overview
|
|
-----------
|
|
|
|
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.
|
|
|
|
|
|
|
|
2. ISO C compatible library
|
|
---------------------------
|
|
|
|
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:
|
|
|
|
* ftell/fseek/fgetpos/fsetpos
|
|
|
|
* tmpfile/tmpnam
|
|
|
|
* The scanf family of functions
|
|
|
|
* time/asctime/ctime/difftime/asctime/gmtime/localtime/mktime/strftime
|
|
|
|
* system
|
|
|
|
* All functions that handle floating point numbers in some manner.
|
|
|
|
* The div and ldiv functions (because cc65 is not able to return
|
|
structs).
|
|
|
|
* All functions handling wide character strings.
|
|
|
|
* Signals and all related functions (having SIGSEGV would be cool:-)
|
|
|
|
* rename/remove/rewind
|
|
|
|
* setbuf/setvbuf/ungetc
|
|
|
|
|
|
|
|
Functions that are limited in any way:
|
|
|
|
* 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).
|
|
|
|
|
|
* 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.
|
|
|
|
|
|
* 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.
|
|
|
|
|
|
* Since there is no such thing as an environment on all supported
|
|
systems, the getenv function will always return a NULL pointer.
|
|
|
|
|
|
* There is no other locale than the "C" locale. The native locale is
|
|
identical to the "C" locale.
|
|
|
|
|
|
In addition to these limitations, some more functions are limited if inlined
|
|
versions are requested by using -Os:
|
|
|
|
* The strlen function only works for strings with a maximum length of
|
|
255 characters.
|
|
|
|
* The isxxx character classification functions from <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).
|
|
|
|
|
|
|
|
3. CPU specific stuff - 6502.h
|
|
------------------------------
|
|
|
|
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.
|
|
|
|
|
|
|
|
4. System specific stuff
|
|
------------------------
|
|
|
|
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
|
|
|
|
* Defines for special keys (like function keys)
|
|
|
|
* Defines for special characters (like the graphics characters)
|
|
|
|
* 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 "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.
|
|
|
|
* 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).
|
|
|
|
|
|
|
|
5. Direct console I/O - conio.h
|
|
-------------------------------
|
|
|
|
The conio 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:
|
|
|
|
c64
|
|
c128
|
|
plus/4
|
|
cbm610 (that is, the complete 600/700 series)
|
|
pet (all PETs except the 2001)
|
|
apple 2
|
|
atari
|
|
|
|
The conio.h header file does also include the system specific header files
|
|
which define constants for special characters and keys.
|
|
|
|
|
|
|
|
6. Using the joystick - joystick.h
|
|
----------------------------------
|
|
|
|
For systems that have a joystick, 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 __JOYSTICK__ on systems that have a joystick.
|
|
|
|
|
|
|
|
7. Bugs/Feedback
|
|
----------------
|
|
|
|
If you have problems using the library, if you find any bugs, or if you've
|
|
written some extensions or otherwise interesting programs, I would be glad
|
|
to hear from you. Feel free to contact me by email (uz@musoftware.de).
|
|
|
|
|
|
|
|
8. Copyright
|
|
------------
|
|
|
|
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:
|
|
|
|
1. 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.
|
|
2. Altered source versions must be plainly marked as such, and must not
|
|
be misrepresented as being the original software.
|
|
3. This notice may not be removed or altered from any source
|
|
distribution.
|
|
|
|
|
|
|
|
|
|
|