Add ext2 superblock, document file system
diff --git a/doc/build.rst b/doc/build.rst
index aefa6bf..3826238 100644
--- a/doc/build.rst
+++ b/doc/build.rst
@@ -36,4 +36,4 @@
gcc gcc-multilib nasm qemu-system-i386 make m4 python3 awk
There are some additional dependencies for building a GRUB ISO but I don't
-remember them at the time of writing.
\ No newline at end of file
+remember them at the time of writing.
diff --git a/doc/filesystem.rst b/doc/filesystem.rst
new file mode 100644
index 0000000..fc8a025
--- /dev/null
+++ b/doc/filesystem.rst
@@ -0,0 +1,23 @@
+Bluejay Filesystem
+==================
+
+Filesystem drivers are still a work in progress. To test a file system you will
+want to create and mount a virtual block device. The makefile in ``src/kernel``
+will generate an ``hd0.img`` EXT2 disk image for you automatically. The default
+size is 32 megabytes, but you can create your own of any size if you want. Once
+the image has been created it will be loaded by QEMU automatically.
+
+In order to write to the virtual hard disk from your host operating system you
+should mount it. The ``make mount`` command in ``src/kernel`` mount the image to
+``$(BLUEJAY_ROOT)/mnt``. It will automatically give read and write permissions
+to the current user. This operation uses ``sudo`` internally, you will be
+prompted for your password.
+
+Virtual Filesystem
+------------------
+
+The Bluejay VFS is heavily inspired by UNIX. It relies on inodes and a tree of
+file nodes. The source can be found in ``src/kernel/vfs.c``. This also exports a
+very low-level API for dealing with files -- including the usual read(),
+write(), readdir(), etc -- but this should not be used for much longer. A high
+level API utilizing file descriptors will be implemented to make this simpler.
diff --git a/doc/index.rst b/doc/index.rst
index 9e3d07b..5baa0ef 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -6,6 +6,9 @@
The Bluejay Operating System
============================
+.. image:: https://builds.sr.ht/~swisschili/bluejay/commits/.build.yml.svg
+ :target: https://builds.sr.ht/~swisschili/bluejay/commits/.build.yml?
+
.. toctree::
:maxdepth: 2
:caption: Contents:
@@ -14,8 +17,7 @@
*
Bluejay is an operating system inspired by UNIX and early Lisp machines.
-Currently it only targets x86, and there are no plans to port to other
-platforms.
+Currently it only targets x86. There are no plans to port to other platforms.
This documentation is incomplete, but should provide a general introduction to
compiling and developing Bluejay.