Yalo
Target
Yalo is a Lisp OS running on bare metal x86-64 hardware. The system programming language is Ink, a new Lisp dialect which combines the elegance of Scheme and powerfulness of Common Lisp. The project webpage is: https://github.com/whily/yalo
Status
The project is only at very very initial stage, with an assembler written in Common Lisp, and a 64 bit bootloader.
"Short term" plan:
- VGA text mode without using BIOS.
- Keyboard handling without using BIOS.
- Switch to 32 bit protected mode.
- Switch to 64 bit long mode.
- Physical/virtual memory management.
- Userland and system call.
- Implement Ink interpreter with assembly.
- Self hosting a more powerful Ink interpreter with Ink itself.
Getting Started
Getting Bootable Image
Currently, cross compilation is needed to build one floppy image containing yalo.
Cross compilation
Although yalo should compile on any Ansi Common Lisp implementation, it is only tested on SBCL. Therefore the following discussion is focused on how to build yalo from SBCL.
Mandatory Requirements:
- [SBCL](http://sbcl.sourceforge.net SBCL)
- git
Optional Requirements:
- Emacs
- SLIME
Getting Source Code
Run following command to anonymously checkout the latest source code of yalo.
$ git clone https://github.com/whily/yalo.git
Setup link for ASDF
Run following commands to make SBCL aware of the ASDF file for the cross compiler.
$ cd yalo/cc
$ ./lnasdf
Build Floppy Image
With SBCL alone
When using SBCL alone, type the following at REPL:
* (require 'asdf)
* (asdf:oos 'asdf:load-op 'cc)
* (in-package :cc)
* (write-kernel "floppy.img")
One may type Ctrl-d
to exit from SBCL.
With Emacs+SLIME
Inside Emacs,
- First type
M-x slime
if SLIME is not started. - Type
M-x slime-load-system
then typecc
when prompted for the system. - At REPL, type
(in-package :cc)
to switch to package cc (alternatively, one can user keyboard shortcutC-x M-p
and then typecc
). - Type
(write-kernel "../floppy.img")
at SLIME REPL to generate the kernel. Here we assume that current directory iscc
of the source tree, thereforefloppy.img
is written directly to the source tree, where scripts to run the image (e.g.run-bochs
) are located.
Run Image
There are various ways to run the image.
Bochs
Go to the root directory of the source code, where script run-bochs
and debug-bochs
are located. Run the scripts and select 6 to
proceed emulation. The difference between run-bochs
and
debug-bochs
is that after selecting 6, emulation starts directly
for run-bochs
; while for debug-bochs
, emulator pauses before BIOS,
and one needs to type c
in the debugger window to continue the
emulation.
Note that on Ubuntu (at least in 16.10), package bochs-x
should be
installed in addition to package bochs
.
QEMU
Similar to Bochs, go to the root directory of the source code, where
script run-qemu
and debug-qemu
are located.
In both run-qemu
and debug-qemu
, QEMU monitor is redirectted to
stdio (via argument -monitor stdio
). Script run-qemu
will start
the emulator without GDB support; while debug-qemu
enables GDB
support: -s
argument makes QEMU listens to port 1234 for GDB, while
-S
argument makes QEMU pauses at the beginning for GDB's continue
command. After running debug-qemu
and starting GDB, first type
target remote :1234
to connect to QEMU, then type command continue
to resume the emulation.
VirtualBox
In the Storage page of the virtual machine settings, right click
and select "Add Floppy Controller". And the select the image file
floppy.img
for floppy drive. In the System page of virtual
machine settings, make sure that Floppy is checked for Boot order.
Assuming the VM name is yalo
, go to the root directory of the source
code, where script run-virtualbox
and debug-virtualbox
are
located. Run script run-virtualbox
to start the emulator, or script
debug-virtualbox
to start the emulator with debug window.
Software version
So far, the development is done on Ubuntu 16.10. For above-mentioned software, the corresponding version is listed below:
- SBCL: 1.3.3
- Emacs: 24.5.1
- SLIME: 2.18
- Bochs: 2.6 (some issues)
- QEMU: 2.6.1
- VirtualBox: 5.1.6 (some issues)