---
title: Homework 1 Part1
author: B073040047
date: 7/14/2020
---
###### tags:OS2020Spring

This homework in [Hackmd Link](https://hackmd.io/@25077667/os-hw1)
---

## Compile your kernel!
Ok, let's start!

:::info
I put all commands in the ` ` zone.
:::

1. Choose your Linux distro.:
* **Recommand** you should split *over 40 GB* disk space to contain your linux distro.
* [Ubuntu](http://www.ubuntu-tw.org/modules/tinyd0/) is the easiest! I assume you are using Ubuntu below.
* Fedora, Gentoo, Arch are also common distro.
* What is distro.?
* A Linux distribution (often abbreviated as distro).
* Ubuntu is a branch of Debian, Fedora is a branch of Red Hat.
* You can get more info. from [Wikipedia](https://en.wikipedia.org/wiki/Linux_distribution).
2. Open the Terminal and type:
* `sudo apt update; sudo apt install build-essential libncurses-dev bison flex libssl-dev libelf-dev liblz4-tool vim libelf-dev -y`
* To install some essential tools
* If you are using non-debian OS, change the **apt** to your package manager.
3. Choose your kernel version:
* Take the **newest** for example.
* Go to [kernel.org](https://www.kernel.org/) to download the newest **stable** version with ==[tarball]==
* Dowload to *~/Download*
* The '~/' means your home directory (a.k.a. /home/\<YOUR NAME\>)

4. Unzip the kernel which you downloaded:
* `tar -xvf ~/Download/linux-*.tar`
5. `cd` in to the folder you unziped:
* `cd ~/Download/linux-*`
6. Edit the version info:
* Makefile
* `vim Makefile`
* [How to use vim?](https://hackmd.io/@93i7xo2/HJFCxkVdV)
* Find the ==EXTRAVERSION \=== and add `-<YOUR STUDENT ID>`
* Example: `EXTRAVERSION = -B073040047`
* Press the `Esc` key to command mode, and type `:wq` to save and quit
> [name=25077667] Murmur: Edit the Makefile is much more easier and needless to search keywords in lots of lists.
>> Actually, Linus torvalds also uses 'Makefile' method. [💕 Valentine's Day Edition 💕](https://github.com/torvalds/linux/commit/f40ddce88593482919761f74910f42f4b84c004b)

7. Set old default config as .config:
* `make olddefconfig`

8. Make!
* `make -j $(nproc)`
* The `$(nproc)` command can get the number of CPUs in your computer, that is, compile kernel in full speed!
* Make until it says:

        Kernel: arch/x86/boot/bzImage is ready  (#3)

9. Make module install
* `sudo make modules_install`

10. Install it to /boot
* `sudo make install`
11. Update Grub2
* `sudo update-initramfs -c -k <THE VERSION YOU COMPILED>`
* Of course, it contains your "stuID" in the end. That you append on.
* `sudo update-grub`

12. Reboot!
* `reboot`

Done.

---

## More Tools:
### Supply packages
It will help you very much if you read this.
[GNU Linux dev](https://hackmd.io/@sysprog/gnu-linux-dev/)

### Vim
What is Vim?
> [Vim Wiki](https://zh.wikipedia.org/zh-tw/Vim)

A picture to realize vim: [picture](http://blog.vgod.tw/wp-content/uploads/2009/12/vgod-vim-cheat-sheet-full.pdf)

### What is sudo?
A meme:
:::spoiler
[source](https://www.facebook.com/307979116481335/photos/a.316111539001426/572406666705244/?type=3&theater)
:::
[wiki](https://zh.wikipedia.org/zh-tw/Sudo)

## About the /boot partition
* What is disk partitions?
- Disks can be parted to many partition, each partitions are independent, for example, you can install different OS in different partition.
- **Partition table type**
There are two different type of partirion table.
**MBR** and **GPT**
- **MBR**
- Master Boot Record , it's an old type method with old **bios** machine
- Limit
- Max size of partition is **2.1TB**
- It can only part **4 Primary Partition**, if you need more partition, you have to part **3P1E**, which **P** means **Primary Partition** and **E** means **Extension Partition**, then part many **Logic Partition** as you want in **Extension Partition**.
- Max partition number : **4**
- p.s. : **P+E** must $\le$ 4 and **E** has to $\le$ 1.
- **GPT**
- GUID Partition Table , it's a newer method with in **UEFI** machine.
- Limit
- Max size of partition is **18EB**
- Max partition number : **128**
* What is partitions' format and flag?
- Partition format is the rule of how files be stored and fetched.
- **NTFS**
- New Technology File System, This is the most used format in **Windows NT OS(>= **Windows NT 3.1**)**.
- Page size : **4KB**
- Max file size : **256TB**
- p.s. : If you want to access **NTFS** in other OS like **Linux**s , you have to via **ntfs-3g**.
- **ext4**
- Fourth extended file system , this is the newest file system in **Unix-like** system.
- Page size : **4KB**
- Max file size : **16TB**
- Max partition cabability : **1EB**
- **fat32**
- File Allocation Table
- Max file size : **4GB**
- Max partition cabability : **8TB**
- p.s. : **efi** partition should be format to **fat32**
-
- Flag
- In MBR format needs a ==Boot flag== to mention boot loader it is bootable.

* How to split your partitions by yourself?
- There are may in **linux** tools like `fdisk`, `gparted`, `lsblk`, `cfdisk`, this examples is using `fdisk`
- `fdisk -l`
- It will print all yout storage devices , sata devices will be list like */dev/sdX* , M.2 pcie devices will be list like */dev/nvme...*.
- `fdisk /dev/sdX`
- select disk **sdX** which you want to modify.
- In `fdisk` press `p` to list partition
- In `fdisk` press `o` to create new dos partition table(MBR) , press `g` to create gpt partition(UEFI)
#### MBR
- part at least one partition which mount as `/`**(root)**
- In `fdisk` press `n` to create a new partition
- In `fdisk` press `t` to modify partition type(linux file system)
#### GPT
- recommend to part at least two partitions , one that mount as `/`**(root)** , the other mount as `/boot`
- In `fdisk` press `n` to create a new partition
- In `fdisk` press `t` to modify partition type(`/` : linux file system , `/boot` : efi)
- formatting you partition
- `mkfs.ext4 /dev/sdXY`
- format partition Y on disk X to ext4
- `mkfs.vfat /dev/sdXY`
- format partition Y on disk X to fat32

* Concluding:
* You can only split fewer space to finish this homework in older version of linux.

## FAQ
1. What should I do if I have the GTX 10xx GPU?
> Please follow these tutorials:
> * https://itsfoss.com/fix-ubuntu-freezing/
> * https://medium.com/caesars-study-review-on-web-development/acpi-osi-linux-nomodeset%E6%98%AF%E4%BB%80%E9%BA%BC%E6%84%8F%E6%80%9D-%E5%8A%9F%E8%83%BD-42d8e2c444c3
> * https://www.twblogs.net/a/5cc24c53bd9eee3aed78a7ef

2. error: /boot/vmlinuz-??? has invalid signature.
> There are two methods to solved this:
> * Resign your kernel and install.
> * Disable the secure boot.

3. How to sign a custom kernel for Secure Boot?
> * https://github.com/jakeday/linux-surface/blob/master/SIGNING.md

4. \[Kernel panic\] not syncing: System is deadlock on memory
> 
> That is your memory is not enough to boot.
> Please give your machine more memory.

5. Ping 140.117.11.1 is not working.
> Well, you can ping 8.8.8.8 first.
> If ping 8.8.8.8 is working, that might be NSYSU's issue.(Please tell teacher)
> else please check your network state.

6. make *** Error
> Please check if you were **following these steps without any error.**
> And make sure some dependency packages are installed.
> <font color=red>If you have any error here, don't keep going down!!</font>

Eg:

> There is an error!! Please check your "debian/canonical-certs.pem" first.
> Don't make install...
> If you don't know what happends. Please Google it first, you can ask me if you can't not find useful answers.

7. Compile kernel takes many time?
> Wait for it.

8. How to find the WSL's root directory to insert files?

Eg:

> There are 2 problems here.
> 1. The root directory is '/', which is called "root"(The root of your file system). And your "home" directory is symboled as "~/", the '~' is an alias for '/home/<YOUR_NAME>'.
>
> 2. You shouldn't have any Linux root file system on Windows (excepat some hacking skills). You cannot use the WSL to compelete this part of homework 1.
> Because the WSL's kernel is not a normal Linux kernel, there are many encapsulation of Hyper-V or NT-Core, which simulate the behavior of Linux kernel. Therefore, you cannot recompile it from the "origional" Linux source code.
>