Battlestar

What is Battlestar?

• A programming language specifically for 64-bit x86 Linux, 32-bit x86 Linux and 16-bit x86 DOS.
• Subset of assembly with an alternative syntax and with support for inline C.
• A work in progress.
• Created for fun and for the educational process.
• The indended purpose is for writing small operating systems, 1k and 4k demoscene demos.

Quick start

Build and install Battlestar, build the samples and run the "life" sample:

• make; sudo make devinstall; make samples; cd life; ./life.sh; cd ..

This requires DosBox, Go, Yasm and GCC.

Build and boot a kernel (requires GCC, Yasm, Battlestar and the qemu-system-i386 executable):

• cd kernel/simple; make boot; cd ../..

Features and limitations

• The resulting executables are tiny!
• "hello world" is only 174 bytes for 32-bit Linux (when using sstrip from elfkickers). (238 bytes for 64-bit Linux, 31 bytes for 16-bit DOS)
• It's possible to write an operating system / kernel with only one source file.
• Full support for inline C (by utilizing gcc).
• C and Battlestar code can exist in the same source file and calls can be made both ways.
• Battlestar programs compiles almost instantly.
• Programs can be run like scripts by including this line at the top: #!/usr/bin/bts
• Interrupts can be called with the same syntax for both 32-bit and 64-bit x86 on Linux.
• Supports 16-bit x86 that can run within DosBox.
• The intermediate assembly is fully commented.
• No register allocator, just an alternative assembly syntax.
• gccgo is not supported yet.

Sample program

This is a 16-bit x86 program, for DOS:

// "Life"
// The original was written by "melezov" (http://256bytes.untergrund.net/demo/334)

fun main
    al = 0x13               // set graphics mode (mode 13h)
                            // 320x200, 256 colors, one byte per pixel
    int 10

    stack -> sp             // pop  sp
    stack -> b              // pop  bx
    stack -> ds             // pop  ds

    ds -> es                // push ds, pop es

    al = 62
    ch = 0xFA
    loopwrite               // rep stosb

    loop

        di <<< 3           // rotate left 3

        di -= 7            // subtraction
        di ^= 2            // xor

        al = readbyte di   // read byte from memory
        al += [di+321]     // add value at [di+321] (pixel on the line below)
        al /= 2

        di -> stack
        write               // stosb
        write

        di += 0x13E
        write
        write

        stack -> di

    end // loops forever

end

In progress

• macOS support
• Reimplementing 16-bit demoscene demos without using any inline assembly
• See TODO

Installation

Make sure Go, Yasm and GCC are installed.

Installation:

sudo make PREFIX=/usr install

For development, install soft links instead:

sudo make install-dev

Build all the samples:

make samples

Build dependencies

• go >= 1.3

Runtime dependencies

• yasm

Optional runtime dependencies

• gcc (for inline C support)
• elftools/sstrip (for even smaller binaries)
• binutils (for disassembling with objdump)
• dosbox (for running 16-bit executables) (only GCC 4.9 and up supports compiling to 16-bit with -m16)
• SDL 2 (must be compiled and installed manually if on Red Hat 6)
• tcc (for even smaller binaries, in many cases)

External links

• Battlestar programs on Rosetta Code

General info

• Version: 0.7.0
• License: BSD-3
• Author: Alexander F. Rødseth <xyproto@archlinux.org>