1 files changed, 88 insertions, 0 deletions

diff --git a/index.md b/index.md
new file mode 100644
index 0000000..bd6fffb
--- /dev/null
+++ b/index.md
@@ -0,0 +1,88 @@
+% WTF is Linux
+
+> What I cannot create, I do not understand.
+>
+> --- <cite>Richard Feynman, 1988</cite>
+
+TODO: add the LM fonts referenced in the CSS
+
+TODO: reference a mono font in the CSS
+
+TODO: fix TOC CSS
+
+TODO: have a POSIX / UNIX / Linux section
+
+TODO: have a QEMU section
+
+TODO: specify dependencies
+
+TODO: Add a plan checklist?
+
+TODO: fix pandoc\'s vimwiki (syntax highlighting, quotes)
+
+TODO: Link manpages
+
+TODO: Add pretty pictures
+
+The Linux Kernel
+----------------
+
+Main article: [kernel](kernel.md)
+
+The Linux kernel is the glue between the hardware and the user space
+programs.
+
+Each time a user program needs to access the hardware (e.g. hard drives,
+network card), it has to go through the kernel through system calls (e.g.
+read/write on a file, `sendto`/`recvfrom` on a socket).
+
+It also decides how processes are run, and is in charge of enforcing
+security.
+
+The filesystem
+--------------
+
+TODO: link to main article
+
+A filesystem is a way of organizing data in the form of files and
+directories. Another way to see it is that since hard drives stores only
+bytes, it is the responsibility of the filesystem to organize these
+bytes such that the kernel can interpret them as files and directories
+and present them to the user (TODO: link mount).
+
+Init
+----
+
+TODO: link to main article
+
+The init program is the first user-space program that the kernel
+launches on boot. Every other program is launched either by init or a
+child of init (direct child or transitive child). Since init is the
+first program launched it always has a PID of 1.
+
+TODO: link to first steps to "user-space booting"
+
+The Shell
+---------
+
+TODO: link to main article
+
+A shell is a programming language whose main goal is to launch other
+programs.
+
+Special filesystems
+-------------------
+
+Some filesystem aren't used to store data, but instead to communicate
+with the kernel. This allows doing various things using only the
+`read`, `write`, and other file-related system calls.
+
+For example, you can list USB devices by listing the content of the
+directory `/sys/bus/usb/devices/`.
+
+TODO: add links to article with list of common special filesystems.
+
+Networking
+----------
+
+TODO: quickly explain static IP vs DHCP, networking interfaces