yusufprompt/cofeuos — reverse-engineered prompt

Build me a small open source hobby operating system for 32 bit x86 that can boot in QEMU. I want it written mostly in C with a simple assembly bootloader, not running on top of Linux or any other OS.

When it starts, switch into a basic VGA graphics mode and draw text using a bitmap font. Show a simple login screen, then drop the user into a Unix style command prompt that looks like user at host with the current path. The shell should understand basic commands like help, ls, cd, pwd, whoami, uname, cat, touch, mkdir, clear, reboot, halt, date, uptime, free, ps, df, env, and a small neofetch style info screen.

Please keep the code modular, with separate pieces for video, keyboard and port input output, strings, memory, a tiny in memory file system, shell commands, and SHA256 for future password checking. Include a Makefile that builds a bootable raw image and a run command for QEMU. Keep it simple and small enough to fit as a tiny freestanding kernel.