Linux build kit

This is useful if you want to quickly create a bootable rootfs from scratch. If you need something like this, try buildroot instead.

Building

An musl toolchain is required for building tonic. The musl libc itself can be configured to install an musl-gcc wrapper script, which can be used to compile tonic without having a full musl toolchain installed.

Configuring

Copy config.mk.def over to config.mk and edit it to match your toolchain settings. The directives follow the usual compilation logic:

• The CC setting names your gcc name. Typical values would be gcc for native (musl-host) compiling, musl-gcc for native architecture but cross-libc, and $ARCH-linux-musl-gcc for cross-compiling
• CROSS_COMPILE is the prefix for buildchain tools like objdump. It is usually empty for native arch builds and end with an hyphen for cross-compiling
• CFLAGS contains your optimisation levels and whether to include symbol tables (for gdb debugging) into your binaries
• LDFLAGS contain the linker flags as given to $CC. Since the required flags are already added by the Makefile, you can leave this empty if you do not want to build statically
• THREADS is the number of parallel build threads. If you put a high number here your build will be faster, at the cost of making it less responsive.

Getting the sources

If you want to download the sources first and compile offline, you can issue make sources to trigger the downloads. Sources will be downloaded on-demand if you skip this.

Compiling

A plain make will compile bin/busybox and bin/mksh and auxillary files of those. Dependency management is done via build target dependencies of the top-level makefile.

Please not that most packages are quite experimental and will likely break, depending on your configuration. For example, the upstream build system of LVM2 deals really bad with static linking.

Testing

make chroot allows you to enter your target system.

Pack into image

Currently there is an target for make boot/initrd which will generate an initramfs from the build artifacts. Feel free to implement your own mechamism here or just pick the binaries manually from bin/.