cl65 Users Guide

Ullrich von Bassewitz,
Greg King

2017-10-16
cl65 is the compile & link utility for cc65, the 6502 C compiler. It was designed as a smart frontend for the C compiler (cc65), the assembler (ca65), the object file converter (co65), and the linker (ld65).

1. Overview

2. Basic Usage

3. More usage

4. Examples

5. Copyright


1. Overview

cl65 is a frontend for cc65, ca65, co65 and ld65. While you may not use the full power of the tools when calling them through cl65, most features are available, and the use of cl65 is much simpler.

2. Basic Usage

The cl65 compile and link utility may be used to convert, compile, assemble and link files. While the separate tools do just one step, cl65 knows how to build object files from C files (by calling the compiler, then the assembler) and other things.

---------------------------------------------------------------------------
Usage: cl65 [options] file [...]
Short options:
  -c                            Compile and assemble but don't link
  -d                            Debug mode
  -g                            Add debug info
  -h                            Help (this text)
  -l name                       Create an assembler listing file
  -m name                       Create a map file
  -mm model                     Set the memory model
  -o name                       Name the output file
  -r                            Enable register variables
  -t sys                        Set the target system
  -u sym                        Force an import of symbol `sym'
  -v                            Verbose mode
  -vm                           Verbose map file
  -C name                       Use linker config file
  -Cl                           Make local variables static
  -D sym[=defn]                 Define a preprocessor symbol
  -E                            Stop after the preprocessing stage
  -I dir                        Set a compiler include directory path
  -L path                       Specify a library search path
  -Ln name                      Create a VICE label file
  -O                            Optimize code
  -Oi                           Optimize code, inline more code
  -Or                           Optimize code, honour the register keyword
  -Os                           Optimize code, inline standard funtions
  -S                            Compile but don't assemble and link
  -T                            Include source as comment
  -V                            Print the version number
  -W name[,...]                 Supress compiler warnings
  -Wa options                   Pass options to the assembler
  -Wc options                   Pass options to the compiler
  -Wl options                   Pass options to the linker

Long options:
  --add-source                  Include source as comment
  --all-cdecl                   Make functions default to __cdecl__
  --asm-args options            Pass options to the assembler
  --asm-define sym[=v]          Define an assembler symbol
  --asm-include-dir dir         Set an assembler include directory
  --bin-include-dir dir         Set an assembler binary include directory
  --bss-label name              Define and export a BSS segment label
  --bss-name seg                Set the name of the BSS segment
  --cc-args options             Pass options to the compiler
  --cfg-path path               Specify a config file search path
  --check-stack                 Generate stack overflow checks
  --code-label name             Define and export a CODE segment label
  --code-name seg               Set the name of the CODE segment
  --codesize x                  Accept larger code by factor x
  --config name                 Use linker config file
  --cpu type                    Set cpu type
  --create-dep name             Create a make dependency file
  --create-full-dep name        Create a full make dependency file
  --data-label name             Define and export a DATA segment label
  --data-name seg               Set the name of the DATA segment
  --debug                       Debug mode
  --debug-info                  Add debug info
  --feature name                Set an emulation feature
  --force-import sym            Force an import of symbol `sym'
  --help                        Help (this text)
  --include-dir dir             Set a compiler include directory path
  --ld-args options             Pass options to the linker
  --lib file                    Link this library
  --lib-path path               Specify a library search path
  --list-targets                List all available targets
  --listing name                Create an assembler listing file
  --list-bytes n                Number of bytes per assembler listing line
  --mapfile name                Create a map file
  --memory-model model          Set the memory model
  --module                      Link as a module
  --module-id id                Specify a module id for the linker
  --o65-model model             Override the o65 model
  --obj file                    Link this object file
  --obj-path path               Specify an object file search path
  --print-target-path           Print the target file path
  --register-space b            Set space available for register variables
  --register-vars               Enable register variables
  --rodata-name seg             Set the name of the RODATA segment
  --signed-chars                Default characters are signed
  --standard std                Language standard (c89, c99, cc65)
  --start-addr addr             Set the default start address
  --static-locals               Make local variables static
  --target sys                  Set the target system
  --version                     Print the version number
  --verbose                     Verbose mode
  --zeropage-label name         Define and export a ZEROPAGE segment label
  --zeropage-name seg           Set the name of the ZEROPAGE segment
---------------------------------------------------------------------------

Most of the options have the same meanings as the corresponding compiler, assembler, and linker options. See the documentation for those tools for an explanation. If an option is available for more than one of the tools, it is set for all tools where it is available. One example for that is -v: The compiler, the assembler, and the linker are all called with the -v switch.

There are a few remaining options that control the behaviour of cl65:

-E

This option is passed to the cc65 compiler; and, it forces cl65 to stop before the assembly step. That means that C-level preprocessor directives are obeyed; and, macroes are expanded. But, the C source isn't compiled. If the -o option isn't used, then the C code results are written into files with a ".i" suffix on their base names. Assembler files, object files, and libraries given on the command line are ignored.

-S

This option forces cl65 to stop before the assembly step. That means that C files are translated into assembler files; but, nothing more is done. Assembler files, object files, and libraries given on the command line are ignored.

-c

This option forces cl65 to stop after the assembly step. That means that C and assembler files given on the command line are translated into object files; but, there is no link step. Object files and libraries given on the command line are ignored.

-o name

The -o option is used for the target name in the final step. That causes problems if the linker will not be called, and there are several input files on the command line. In that case, the name given with -o will be used for all of them, which makes the option pretty useless. You shouldn't use -o when more than one output file is created.

--print-target-path

This option prints the absolute path of the target file directory, and exits then. It is supposed to be used with shell backquotes or the GNU make shell function. That way, you can write build scripts or Makefiles accessing target files without any assumption about the cc65 installation path.

-t sys, --target sys

The default for this option is different from the compiler and linker, in the case that the option is missing: While the other tools (compiler, assembler, and linker) will use the "none" system settings by default, cl65 will use "c64" as a target system by default. That was chosen because most people seem to use cc65 to develop for the C64.

-Wa options, --asm-args options

Pass options directly to the assembler. This may be used to pass options that aren't directly supported by cl65. Several options may be separated by commas; the commas are replaced by spaces when passing them to the assembler. Beware: Passing arguments directly to the assembler might interfere with some of the defaults because cl65 doesn't parse the options passed. So, if cl65 supports an option by itself, do not pass that option to the assembler by means of the -Wa switch.

-Wc options, --cc-args options

Pass options directly to the compiler. This may be used to pass options that aren't directly supported by cl65. Several options may be separated by commas; the commas are replaced by spaces when passing them to the compiler. Beware: Passing arguments directly to the compiler might interfere with some of the defaults because cl65 doesn't parse the options passed. So, if cl65 supports an option by itself, do not pass that option to the compiler by means of the -Wc switch.

-Wl options, --ld-args options

Pass options directly to the linker. This may be used to pass options that aren't directly supported by cl65. Several options may be separated by commas; the commas are replaced by spaces when passing them to the linker. Beware: Passing arguments directly to the linker might interfere with some of the defaults because cl65 doesn't parse the options passed. So, if cl65 supports an option by itself, do not pass that option to the linker by means of the -Wl switch.

3. More usage

Because cl65 was created to simplify the use of the cc65 development package, it tries to be smart about several things.

The command line is parsed from left to right, and the actual processing tool (compiler, assembler, ...) is invoked whenever a file name is encountered. This means that only the options to the left of a file name are in effect when this file is processed. It does also mean that you're able to specify different options for different files on the command line. As an example.

        cl65 -Oirs main.c -O -g module.c

translates main.c with full optimization and module.c with less optimization and debug info enabled.

The type of an input file is derived from its extension:

Please note that the program cannot handle input files with unknown file extensions.

4. Examples

The morse trainer software, which consists of one C file (morse.c) and one assembler file (irq.s) will need the following separate steps to compile into an executable named morse:

        cc65 -g -Oi -t c64 morse.c
        ca65 -g morse.s
        ca65 -g irq.s
        ld65 -o morse -t c64 c64.o morse.o irq.o c64.lib

When using cl65, this is simplified to

        cl65 -g -Oi morse.c irq.s

As a general rule, you may use cl65 instead of cc65 at most times, especially in makefiles to build object files directly from C files. Use

        .c.o:
                cl65 -g -Oi $<

to do this.

5. Copyright

cl65 (and all cc65 binutils) are (C) Copyright 1998-2004 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.