Summer of Code results: Miniaturize NetBSD

Here is my summary of project goals and results for Lloyd Parkes' Summer of Code project, Miniaturize NetBSD.

Lloyd's project was concerned with helping developers to build small, bootable NetBSD system images by extending NetBSD's cross-compilation toolset and adding new kernel facilities.

Goals

Lloyd set out with two goals. One goal was to add to build.sh, the script that orchestrates cross-building the NetBSD kernels & userland, a new target that indicates a configuration file for a NetBSD system image. The configuration file would tell the type and layout of the system image: either an NFS root, a kernel with root on an embedded memory disk, or a bootable disk image with a BSD disklabel and/or Master Boot Record, an FFS or an ISO9660 filesystem. The file would also tell which NetBSD distribution files to include, and which to exclude, and which kernel to install. build.sh would follow the instructions in the configuration file, producing either a bootable disk image, a compressed TAR file of a root filesystem and/or a kernel.

The second goal was to add to the kernel the ability to boot from a filesystem residing in a compressed disk image such as vndcompress(1) creates.

By mid-summer, Lloyd and I agreed to discard the second goal. The first goal entailed more than enough work to occupy Lloyd for the summer; to complete additionally a programming task in the kernel was not realistic.

Results

Lloyd created, for the first time, a facility for building small NetBSD systems that is integrated into build.sh. He demonstrated its usefulness for building system images for Lloyd's own Kerberos Key Distribution Center (Kerberos KDC), and for the CUWiN wireless mesh system. Watch for Lloyd's work to be integrated with NetBSD.