Here you will find documentation related to Linux Operating System and Open Source in general.
Linux Documentation
1. Installation of Grub2
2. HDD Performance & Test
3. Make Initramfs
4. Create USB Bootable Disk
5. Network Command
6. Pictures Script
7. Set Keyboard Layout
8. User Management
9. Kernel Compilation
10. File Operation
11. File Permission
12. FSTAB File and Mount Command
Android Documentation
1. Android Phone System Command