To build ELKS, you need a development environment on Linux or macOS, including:
- flex
- bison
- texinfo
- libncurses5-dev
- mtools-4.0.23 (for MSDOS/FAT images)
- compress (for compressed man pages; use
sudo apt-get install ncompress)
1- Create a cross subfolder:
mkdir cross
2- Build the cross tool chain, mainly based on GCC-IA16. This step is quite long, but only needs to be done once:
tools/build.sh
3- Set up your environment (PATH, TOPDIR and CROSSDIR):
. ./env.sh (note the '.' before the script, or use source ./env.sh for csh)
4- Configure the kernel, the user land and the target image format. This creates the configuration file .config:
make menuconfig
5- Build the kernel, the user land and the target image:
make all
The target root folder is built in target, and depending on your
configuration, that folder is used to create either a floppy disk image
(fd360, fd720, fd1200, fd1440, fd2880), a flat 32MB hard disk image (without MBR),
or a ROM file image into the image folder. The image extension is '.img'
and will be in either ELKS (MINIX) or MSDOS (FAT) filesystem format.
Building FAT images requires the 'mtools-4.0.23' package to be installed.
6- Before writing that image on the real medium, you can test it first on QEMU:
./qemu.sh
7- You can then modify the configuration or the sources and repeat from the step 4 after cleaning only the kernel, the user land and the image:
make clean
To clean the kernel build objects only, make kclean can be used.
8- One can also build ELKS distribution images for the entire suite of supported floppy formats and hard disks (with and without MBRs) for both MINIX and MSDOS FAT format. To create these images, use the following:
cd image; make images
A script is provided to automate the whole build process (cross tool chain, configuration, kernel, user land and target image), which is run by GitHub on PRs and pushes:
./build.sh
Note: all the scripts must be executed within the top folder of the ELKS repository as the current one (= TOPDIR).