High-performance /sbin/init program for Linux
This is designed to do literally nothing but accept binaries over the network and run them as a child of init.
If you pipe a file to <server ip>:1234 it will run it and pipe the
stderr and stdout back to you
If you connect to <server ip>:1235 init will send SIGKILL to all
processes on the system but itself. This is a measure to allow resetting
the system if a binary was uploaded that had issues. This port neither
sends or recieves anything, it simply kills upon getting a TCP connection.
For a simple headless Linux machine running a basic kernel, you'll want flags like this:
console=ttyS1,115200 rw root=/dev/sda ip=dhcp
This enables a console on ttyS1 (in my case that's COM2, the
Serial-over-LAN port for IPMI), rw specifies that the root mount should
be read-writable (required since we drop a file), root specifies the root
filesystem device (in our case we used an unpartioned flash drive with
vfat), and ip=dhcp is the coolest part, this allows the kernel to get
a DHCP lease on any active NICs. This is mandatory because we use
networking in init without any configuration of the network.
TL;DR: Build a kernel that can read from your drive and do networking, put this
on it at /sbin/init, boot the kernel and it will run this program.