This Homebrew formula packages the excellent TOS/libc project by Fredrik Noring — a modern C standard library tailored for Atari TOS development. All credit for the library and the tools goes to Fredrik. This tap simply makes it easier to install and use on macOS via Homebrew.

brew tap kareandersen/toslibc
brew install --HEAD toslibc

Note: Required dependencies, including m68k-elf-gcc and m68k-elf-binutils, will be installed automatically by Homebrew.

To compile programs using TOS/libc, utilize pkg-config to retrieve the necessary compiler and linker flags.

pkg-config --cflags toslibc

pkg-config --libs toslibc

Some linker flags need to be specified separately:

pkg-config --variable=TOSLIBC_LDFLAGS toslibc

In your Makefile, you might integrate these as follows:

CFLAGS += $(shell pkg-config --cflags toslibc)
LDFLAGS += $(shell pkg-config --libs toslibc)
EXTRA_LDFLAGS += $(shell pkg-config --variable=TOSLIBC_LDFLAGS toslibc)

⚠️ Important: TOSLIBC_LDFLAGS must appear last in the final link command to avoid section garbage collection issues.

This formula installs the toslink utility — a custom linker that converts ELF object files into Atari TOS executable files.

To use toslink, you must first generate a relocatable object file (.r.o) from your compiled .o file using m68k-elf-ld. This step requires a custom linker script (prg.ld), which is automatically referenced when using the flags provided by pkg-config.

m68k-elf-ld myprog.o $(pkg-config --libs toslibc) $(pkg-config --variable=TOSLIBC_LDFLAGS toslibc) -o myprog.r.o

Then invoke toslink to produce the final Atari TOS executable:

toslink -o myprog.prg myprog.r.o

The linker script (prg.ld) ensures proper memory layout and section alignment for TOS compatibility. It is installed alongside the library and referenced via the TOSLIBC_LDFLAGS variable, so you typically don’t need to reference it manually.

toslink is placed in your PATH for easy access after installation.

Example source files and a working Makefile are installed to:

$(brew --prefix)/share/toslibc/examples

To build the examples:

cd $(brew --prefix)/share/toslibc/examples
make

To verify the installation:

brew test toslibc

This compiles and links a small test program using all relevant pkg-config flags, and checks that it generates a valid TOS executable.

Contributions are welcome! Please fork the repository and submit a pull request with your enhancements.

This formula and its packaging metadata are distributed under the terms of the LGPL-2.1 License, consistent with the upstream TOS/libc licensing model.

Upstream TOS/libc is triple-licensed under:

• GPL-2.0
• LGPL-2.1
• MIT

See the upstream project for full licensing details.