makecore

makecore is a Bash-based build script that creates a tiny bootable Linux ISO for x86_64.

It automates:

• Linux kernel download/build
• Optional glibc build (for dynamic BusyBox)
• BusyBox build (static by default)
• Root filesystem + initramfs generation
• Bootable ISO creation with Syslinux/Isolinux
• Optional QEMU run

Repository Layout

• script.sh: main entry point
• config: build configuration (URLs + options)
• kernel.config: predefined kernel config used by default
• sources/: optional local source archives (offline/local mode)
• ntmkstdlib.sh: logging/error utility functions used by script.sh

Prerequisites

Install common build and runtime tools:

• bash, make, gcc, tar, cpio, gzip, sed, find, wget
• one ISO tool: xorriso or mkisofs or genisoimage
• qemu-system-x86_64 (only if you want run)

Notes:

• USE_LOCAL_SOURCE=true in config means the script first looks for archives in sources/.
• If an archive is missing locally, it falls back to downloading it.

Quick Start

From the project root:

chmod +x script.sh
./script.sh all

This builds everything and produces:

• ISO: ~/work/tmp/out/minidistro.iso
• Working directory: ~/work/tmp

Run the ISO in QEMU:

./script.sh run

Commands

./script.sh all    # full pipeline: kernel -> (glibc) -> busybox -> initramfs -> ISO
./script.sh iso    # rebuild ISO stage (expects kernel/initramfs already present)
./script.sh run    # boot generated ISO with qemu-system-x86_64
./script.sh clean  # remove ~/work/tmp workspace

Configuration

Edit config to tune source versions and behavior:

• KERNEL_SOURCE_URL: Linux kernel tarball
• GLIBC_SOURCE_URL: glibc tarball
• BUSYBOX_SOURCE_URL: BusyBox tarball
• SYSLINUX_SOURCE_URL: Syslinux tarball
• USE_PREDEFINED_KERNEL_CONFIG: if true, uses kernel.config; otherwise uses x86_64_defconfig
• USE_LOCAL_SOURCE: if true, use local archives in sources/ when available
• JOB_FACTOR: build jobs multiplier (jobs = CPU cores * JOB_FACTOR)
• CFLAGS: flags passed to BusyBox build
• USE_GLIBC: if true, builds glibc and uses dynamic BusyBox; default behavior is static BusyBox

Current script behavior:

• USE_PREDEFINED_BUSYBOX_CONFIG, OVERLAY_TYPE, USE_BOOT_LOGO, and STATIC_GET_SOURCE_URL are present in config but not consumed by script.sh.

Boot Behavior

The generated initramfs starts /init, mounts proc, sys, and dev, then launches a shell:

• kernel console is set to ttyS0
• ISO is intended for serial console usage (-nographic in QEMU)

Troubleshooting

• If ./script.sh iso fails with missing kernel/initramfs, run ./script.sh all first.
• If ISO creation fails, install one of: xorriso, mkisofs, genisoimage.
• If download fails in local mode, verify archives exist in sources/ or set USE_LOCAL_SOURCE=false.
• If build is slow, increase JOB_FACTOR in config.