PSLBoot

Polytech Simple Linux Bootloader (WIP)

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What works

PSLBoot can load a Linux bzImage and initrd from the first Linux/ext2 partition of a raw QEMU IDE disk. Stage 2 is stored in the post-MBR gap starting at LBA 1, so create the first partition at the usual 1 MiB offset or later.

Build

make

This creates build/bootloader.img, mostly useful as a build artifact sanity check. For a real Debian disk image, install the loader into an existing raw image:

make install DISK=debian-ext2.img

The install target preserves the partition table, writes MBR boot code, writes the boot signature, and writes Stage 2 at LBA 1.

Debian/ext2 disk expectations

• QEMU disk must be attached as the primary IDE disk.
• The first Linux partition must contain an ext2 filesystem, not ext4-with-extents.
• Kernel/initrd are searched as /boot/vmlinuz, /boot/initrd.img, then by vmlinuz* and initrd.img* inside /boot.
• Kernel command line is currently built in as: root=/dev/sda1 ro console=tty0 console=ttyS0,115200n8.

Example run after installing into a prepared disk:

make run

or directly:

"C:/Program Files/qemu/qemu-system-i386.exe" -m 256M -drive format=raw,file=debian-ext2.img -serial stdio