TranslateProject/sources/tech/20190326 How to use NetBSD on a Raspberry Pi.md

[#]: collector: (lujun9972)
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[#]: subject: (How to use NetBSD on a Raspberry Pi)
[#]: via: (https://opensource.com/article/19/3/netbsd-raspberry-pi)
[#]: author: (Seth Kenlon  https://opensource.com/users/seth)

How to use NetBSD on a Raspberry Pi
======

Experiment with NetBSD, an open source OS with direct lineage back to the original UNIX source code, on your Raspberry Pi.

![][1]

Do you have an old Raspberry Pi lying around gathering dust, maybe after a recent Pi upgrade? Are you curious about [BSD Unix][2]? If you answered "yes" to both of these questions, you'll be pleased to know that the first is the solution to the second, because you can run [NetBSD][3], as far back as the very first release, on a Raspberry Pi.

BSD is the Berkley Software Distribution of [Unix][4]. In fact, it's the only open source Unix with direct lineage back to the original source code written by Dennis Ritchie and Ken Thompson at Bell Labs. Other modern versions are either proprietary (such as AIX and Solaris) or clever re-implementations (such as Minix and GNU/Linux). If you're used to Linux, you'll feel mostly right at home with BSD, but there are plenty of new commands and conventions to discover. If you're still relatively new to open source, trying BSD is a good way to experience a traditional Unix.

Admittedly, NetBSD isn't an operating system that's perfectly suited for the Pi. It's a minimal install compared to many Linux distributions designed specifically for the Pi, and not all components of recent Pi models are functional under NetBSD yet. However, it's arguably an ideal OS for the older Pi models, since it's lightweight and lovingly maintained. And if nothing else, it's a lot of fun for any die-hard Unix geek to experience another side of the [POSIX][5] world.

### Download NetBSD

There are different versions of BSD. NetBSD has cultivated a reputation for being lightweight and versatile (its website features the tagline "Of course it runs NetBSD"). It offers an image of the latest version of the OS for every version of the Raspberry Pi since the original. To download a version for your Pi, you must first [determine what variant of the ARM architecture your Pi uses][6]. Some information about this is available on the NetBSD site, but for a comprehensive overview, you can also refer to [RPi Hardware History][7].

The Pi I used for this article is, as far as I can tell, a Raspberry Pi Model B Rev 2.0 (with two USB ports and no mounting holes). According to the [Raspberry Pi FAQ][8], this means the architecture is ARMv6, which translates to **earmv6hf** in NetBSD's architecture notation.

![NetBSD on Raspberry Pi][9]

If you're not sure what kind of Pi you have, the good news is that there are only two Pi images, so try **earmv7hf** first; if it doesn't work, fall back to **earmv6hf**.

For the easiest and quickest install, use the binary image instead of an installer. Using the image is the most common method of getting an OS onto your Pi: you copy the image to your SD card and boot it up. There's no install necessary, because the image is a generic installation of the OS, and you've just copied it, bit for bit, onto the media that the Pi uses as its boot drive.

The image files are found in the **binary > gzimg** directories of the NetBSD installation media server, which you can reach from the [front page][3] of NetBSD.org. The image is **rpi.img.gz** , a compressed **.img** file. Download it to your hard drive.

Once you have downloaded the entire image, extract it. If you're running Linux, BSD, or MacOS, you can use the **gunzip** command:

```
$ gunzip ~/Downloads/rpi.img.gz
```

If you're working on Windows, you can install the open source [7-Zip][10] archive utility.

### Copy the image to your SD card

Once the image file is uncompressed, you must copy it to your Pi's SD card. There are two ways to do this, so use the one that works best for you.

#### 1\. Using Etcher

Etcher is a cross-platform application specifically designed to copy OS images to USB drives and SD cards. Download it from [Etcher.io][11] and launch it.

In the Etcher interface, select the image file on your hard drive and the SD card you want to flash, then click the Flash button.

![Etcher][12]

That's it.

#### 2\. Using the dd command

On Linux, BSD, or MacOS, you can use the **dd** command to copy the image to your SD card.

  1. First, insert your SD card into a card reader. Don't mount the card to your system because **dd** needs the device to be disengaged to copy data onto it.

  2. Run **dmesg | tail** to find out where the card is located without it being mounted. On MacOS, use **diskutil list**.

  3. Copy the image file to the SD card:

```
$ sudo dd if=~/Downloads/rpi.img of=/dev/mmcblk0 bs=2M status=progress
```

Before doing this, you _must be sure_ you have the correct location of the SD card. If you copy the image file to the incorrect device, you could lose data. If you are at all unsure about this, use Etcher instead!




When either **dd** or Etcher has written the image to the SD card, place the card in your Pi and power it on.

### First boot

The first time it's booted, NetBSD detects that the SD card's filesystem does not occupy all the free space available and resizes the filesystem accordingly.

![Booting NetBSD on Raspberry Pi][13]

Once that's finished, the Pi reboots and presents a login prompt. Log into your NetBSD system using **root** as the user name. No password is required.

### Set up a user account

First, set a password for the root user:

```
# passwd
```

Then create a user account for yourself with the **-m** option to prompt NetBSD to create a home directory and the **-G wheel** option to add your account to the wheel group so that you can become the administrative user (root) as needed:

```
# useradd -m -G wheel seth
```

Use the **passwd** command again to set a password for your user account:

```
# passwd seth
```

Log out, and then log back in with your new credentials.

### Add software to NetBSD

If you've ever used a Pi, you probably know that the way to add more software to your system is with a special command like **apt** or **dnf** (depending on whether you prefer to run [Raspbian][14] or [FedBerry][15] on your Pi). On NetBSD, use the **pkg_add** command. But some setup is required before the command knows where to go to get the packages you want to install.

There are ready-made (pre-compiled) packages for NetBSD on NetBSD's servers using the scheme **<[ftp://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/[PORT]/[VERSION]/All>][16]**. Replace PORT with the architecture you are using, either **earmv6hf** or **earmv7hf**. Replace VERSION with the NetBSD release you are using; at the time of this writing, that's **8.0**.

Place this value in a file called **/etc/pkg_install.conf**. Since that's a system file outside your user folder, you must invoke root privileges to create it:

```
$ su -
<password>
# echo "PKG_PATH=<ftp://ftp.NetBSD.org/pub/pkgsrc/packages/NetBSD/earmv6hf/8.0/All/>" >> /etc/pkg_install.conf
```

Now you can install packages from the NetBSD software distribution. A good first candidate is Bash, commonly the default shell on a Linux (and Mac) system. Also, if you're not already a Vi text editor user, you may want to try something more intuitive such as [Jove][17] or [Nano][18]:

```
# pkg_add -v bash jove nano
# exit
$
```

Unlike many Linux distributions ([Slackware][19] being a notable exception), NetBSD does very little configuration on your behalf, and this is considered a feature. So, to use Bash, Jove, or Nano as your default toolset, you must set the configuration yourself.

You can set many of your preferences dynamically using environment variables, which are special variables that your whole system can access. For instance, most applications in Unix know that if there is a **VISUAL** or **EDITOR** variable set, the value of those variables should be used as the default text editor. You can set these two variables temporarily, just for your current login session:

```
$ export EDITOR=nano
# export VISUAL=nano
```

Or you can make them permanent by adding them to the default NetBSD **.profile** file:

```
$ sed -i 's/EDITOR=vi/EDITOR=nano/' ~/.profile
```

Load your new settings:

```
$ . ~/.profile
```

To make Bash your default shell, use the **chsh** (change shell) command, which now loads into your preferred editor. Before running **chsh** , though, make sure you know where Bash is located:

```
$ which bash
/usr/pkg/bin/bash
```

Set the value for **shell** in the **chsh** entry to **/usr/pkg/bin/bash** , then save the document.

### Add sudo

The **pkg_add** command is a privileged command, which means to use it, you must become the root user with the **su** command. If you prefer, you can also set up the **sudo** command, which allows certain users to use their own password to execute administrative tasks.

First, install it:

```
# pkg_add -v sudo
```

And then use the **visudo** command to edit its configuration file. You must use the **visudo** command to edit the **sudo** configuration, and it must be run as root:

```
$ su
# SUDO_EDITOR=nano visudo
```

Once you are in the editor, find the line allowing members of the wheel group to execute any command, and uncomment it (by removing **#** from the beginning of the line):

```
### Uncomment to allow members of group wheel to execute any command
%wheel ALL=(ALL) ALL
```

Save the document as described in Nano's bottom menu panel and exit the root shell.

Now you can use **pkg_add** with **sudo** instead of becoming root:

```
$ sudo pkg_add -v fluxbox
```

### Net gain

NetBSD is a full-featured Unix operating system, and now that you have it set up on your Pi, you can explore every nook and cranny. It happens to be a pretty lightweight OS, so even an old Pi with a 700mHz processor and 256MB of RAM can run it with ease. If this article has sparked your interest and you have an old Pi sitting in a drawer somewhere, try it out!

--------------------------------------------------------------------------------

via: https://opensource.com/article/19/3/netbsd-raspberry-pi

作者：[Seth Kenlon (Red Hat, Community Moderator)][a]
选题：[lujun9972][b]
译者：[译者ID](https://github.com/译者ID)
校对：[校对者ID](https://github.com/校对者ID)

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[a]: https://opensource.com/users/seth
[b]: https://github.com/lujun9972
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/code_computer_development_programming.png?itok=4OM29-82
[2]: https://en.wikipedia.org/wiki/Berkeley_Software_Distribution
[3]: http://netbsd.org/
[4]: https://en.wikipedia.org/wiki/Unix
[5]: https://en.wikipedia.org/wiki/POSIX
[6]: http://wiki.netbsd.org/ports/evbarm/raspberry_pi
[7]: https://elinux.org/RPi_HardwareHistory
[8]: https://www.raspberrypi.org/documentation/faqs/
[9]: https://opensource.com/sites/default/files/uploads/pi.jpg (NetBSD on Raspberry Pi)
[10]: https://www.7-zip.org/
[11]: https://www.balena.io/etcher/
[12]: https://opensource.com/sites/default/files/uploads/etcher_0.png (Etcher)
[13]: https://opensource.com/sites/default/files/uploads/boot.png (Booting NetBSD on Raspberry Pi)
[14]: http://raspbian.org/
[15]: http://fedberry.org/
[16]: ftp://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/%5BPORT%5D/%5BVERSION%5D/All%3E
[17]: https://opensource.com/article/17/1/jove-lightweight-alternative-vim
[18]: https://www.nano-editor.org/
[19]: http://www.slackware.com/