bfkernel

A Linux-hosted Brainfuck OS kernel. Boots a full shell environment where every program is a .bf file. Includes a scheduler, virtual filesystem, REPL, and a stdlib of classic programs.

Build

make install

Requires: gcc, make. Optional: libreadline-dev (for arrow-key history).

apt install libreadline-dev   # Debian/Ubuntu

Run

./bfkernel                    # launch shell
./bfkernel hello.bf           # run a .bf file directly
./bfkernel -e '++++++++++[>++++++++++<-]>--.+.+++++++.'   # inline code
./bfkernel -l 1000000         # set step limit

Shell Commands

Command	Description
run <file.bf>	run a brainfuck program
run -i <code>	run inline brainfuck code
bg <file.bf>	run in background (scheduler)
repl	interactive BF REPL with persistent tape
ps	list all processes
kill <pid>	kill a process
wait <pid>	wait for process to finish
ls [path]	list directory
cd <path>	change directory
pwd	print working directory
cat <file>	print file
write <file> <data>	write data to file
mkdir <dir>	make directory
tape <file.bf> [n]	dump tape after run
bench <file.bf>	run and show step count + timing
limit [n]	get/set step limit
history	command history
uname	kernel info
exit	shutdown

Stdlib Programs (in /bin/)

File	Does
hello.bf	Hello World
cat.bf	cat stdin to stdout
echo.bf	echo stdin
fibonacci.bf	print fibonacci sequence
rot13.bf	ROT13 cipher
squares.bf	print squares
reverse.bf	reverse input
uppercase.bf	uppercase input
99bottles.bf	99 bottles of beer
truth.bf	print "yes"
twoplus.bf	2+5 = G (ASCII 71)

Architecture

bfkernel/
  kernel/
    bf_main.c        entry point, arg parsing, boot
    bf_scheduler.c   round-robin process scheduler
  interpreter/
    bf_interpreter.c tape VM, loop table, step engine
  fs/
    bf_fs.c          virtual filesystem (backed by ./bfroot/)
  shell/
    bf_shell.c       interactive shell + all builtins
  include/
    bf_types.h       all types and constants
    bf_interpreter.h
    bf_scheduler.h
    bf_fs.h
    bf_shell.h
  stdlib/
    *.bf             standard library programs
  Makefile

REPL Example

bfsh:/> repl
bf> ++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.
bf>
H
bf> reset
[repl] tape reset
bf> q

Inline Run Example

bfsh:/> run -i "++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++."
Hello

Background Processes

bfsh:/> bg /bin/fibonacci.bf
[bg] pid 1 started
bfsh:/> ps
PID    NAME                 STATE      STEPS
---    ----                 -----      -----
1      /bin/fibonacci.bf    running    0
bfsh:/> wait 1