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+---
+title: WTF is Linux
+author: Rémi Nicole <remi.nicole@smile.fr>
+date: 2020-09-22
+slide-level: 2
+aspectratio: 169
+
+theme: metropolis
+colortheme: owl
+beameroption: "show notes on second screen=right"
+
+toc: true
+highlightstyle: breezedark
+lang: en-US
+
+bibliography: ../bibliography.bib
+---
+
+# Before we get started
+
+## Requirements for the practical works
+
+- A GNU/Linux machine
+- An SD card reader
+- A partner (if you want to)
+
+## The website
+
+- In here: <https://git.esiee.fr/nicolere/wtf-is-linux-website>
+- Please contribute! <https://git-send-email.io/>
+- Learn Git: <https://git-scm.com/book/en/v2>
+
+
+::: notes
+
+- If you have already used Git before, try to use the send-email approach
+- If not, you can use the pull request method
+
+:::
+
+## Where were we?
+
+::: notes
+
+- Some history of computer science
+- Downloaded, configured and build a kernel
+- Tried to boot a Linux system, without success
+
+:::
+
+# The file system
+
+## Purpose
+
+- Organize ones and zeroes into files and directories
+- It is therefore a "format"
+- We can ask the kernel to represent the files and directories somewhere
+
+::: notes
+
+- Storage devices (HDDs, SSDs) just store ones and zeroes
+- Representing the files is what is called "mounting"
+
+:::
+
+## Storage devices
+
+- HDDs, SSDs, Flash Memory, everything is different
+- We don't care about their differences
+- Thank you device drivers
+
+
+## Well-known file systems
+
+- FAT32
+- ext4
+- NTFS
+
+::: notes
+
+- FAT32 works everywhere but
+        - Fragmentation
+        - no files bigger than 4 GB
+        - no advanced features (FAT is quite old)
+- ext4 is the de facto Linux file system
+- NTFS is the standard Windows file system
+
+:::
+
+
+## Anatomy of a file system
+
+- Need to store the content of files
+- Need to store metadata
+        - File names
+        - File permissions
+        - Where the content is
+        - etc.
+
+---
+
+![FAT32 format [@mdpi:fat32]](../res/fat32.jpg){ width=70% }
+
+---
+
+![FAT32 table [@wikimedia:fat32_table]](../res/Fat32_structure.png){ height=70% }
+
+## Partitions
+
+- We need a way to store **several** file systems in a single hard drive
+- This is quite similar to file systems
+        - But we store partitions instead of files
+- We call the format a "partitioning scheme"
+
+::: notes
+
+- Similar in that:
+        - This is a format
+        - We need metadata
+        - And we need space for the partitions
+
+:::
+
+## Well-known partitioning scheme
+
+- MBR
+- GPT
+
+## Anatomy of a partitioning scheme
+
+![GPT format [@wikimedia:gpt]](../res/GUID-Partition-Table-Scheme.png){ height=80% }
+
+## Block devices
+
+- We need a way for the kernel to present us devices
+- You can't directly present files
+        - We may not have a file system in a partition
+        - The kernel doesn't automatically where to "mount" the files
+
+
+::: notes
+
+- Philosophy of "everything is a file"
+- Look at `/dev`
+- `/dev/sda` is the first SCSI disk
+- `/dev/sda1` is the first partition in the first SCSI disk
+- Theses special files behave a lot like normal files
+
+:::
+
+## Mounting
+
+- To the terminal!
+
+
+::: notes
+
+- Also talk about mount options
+
+:::
+
+## Special file system
+
+- Common examples: `tmpfs`, `devtmpfs`, `sysfs` & `proc`
+
+# Init
+
+## Purpose
+
+- We need a process launched by the kernel
+- A process can launch other processes
+- So let's make it 1
+
+## Busybox
+
+
+# References