Initial Setup

Once you've restored a system image to your SD card, insert it into your device and attach HDMI, Ethernet and/or your serial cable before applying power.

Logging In

If HDMI output is supported on your device, connect it to your monitor before applying power. The bootloader and kernel will spew text on screen for a few seconds before the Shedbuilt banner and login prompt appear. If HDMI isn't yet supported or you prefer to run headless, you can instead pop in an Ethernet cable and log in using OpenSSH. To determine your device's IP address, log into your router's admin interface and look for a DHCP lease for 'shedbuilt'. Once you know the device's IP, you connect from another computer using ssh in the Terminal, like so:

# ssh root@

You can also log in using a serial cable using screen or a similar utility at 115200 baud:

# screen /dev/ttyUSB0 115200

Initial login must be performed as the root user whose password is shedbuilt.

Once you've logged in, it's strongly advised that you change the root password from its default to a secure password of your choosing. Do so by entering passwd root.

Set the Timezone

While Shedbuilt is configured to set the internal clock using network time servers by default, you'll still need to set your timezone to have the correct local time. First, look up the name of your timezone as listed in:

# timedatectl list-timezones

Then pass that timezone name back to timedatectl like this:

# timedatectl set-timezone <your timezone>

Resize the Root Partition

Shedbuilt system images define a root partition a mere 1 or 2GB in size. Now's a good time to resize it to fill more or all of your SD card. To do so you'll need to delete and recreate your the root partition using fdisk:

# fdisk /dev/mmcblk0
: d
: n
: p
: 1
: 4096 [starting at this offset gives the bootloader, u-boot, a bit of breathing room]
: [hit 'enter' to accept the end of the card as the end of the partition]
: n [when prompted, choose not to overwrite the existing EXT4 signature so the filesystem remains intact]
: p
: w

Use the following command to finish resizing the partition

# resize2fs /dev/mmcblk0p1

You can use the command df to verify that the size of the root partition, mounted at / now matches the size of your SD card.

Create a Swap File

If you're going to be compiling software on a device with less than a gigabyte of RAM, you'd best create a swap file to avoid any out-of-memory unpleasantness. 512MB or so should do the trick:

# dd if=/dev/zero of=/var/swap bs=1M count=512
# chmod 600 /var/swap
# mkswap /var/swap
# swapon /var/swap

Ensure Proper SD Card / eMMC Settings

If your SD Card or eMMC storage device supports it, it's a good idea to set the 'discard' mount option for all of its partitions in /etc/fstab. This will allow ERASE operations to be performed continuously, helping to maintain the performance and longevity of solid-state storage. You can edit this file using the included vim text editor:

# vim /etc/fstab

With the modification, your /etc/fstab file will look a bit like this:

# Begin /etc/fstab

# file system  mount-point  type     options             dump  fsck
#                                                              order

/dev/mmcblk0p1 / ext4 defaults,discard,noatime,commit=600,errors=remount-ro 0 1
/var/swap swap swap pri=-1 0 0

# End /etc/fstab

If you've created a swap file you'll need to remove the '#' in front of the entry for /var/swap in /etc/fstab to ensure it's enabled automatically on boot.

Creating a Normal User

Running every command as root is a bit like leading a bull through a china shop so it's a good idea to create a normal user for yourself like so:

# useradd -m -G users,wheel,video,audio,input,dialout,usb,cdrom -s /bin/bash yournamehere
# passwd yournamehere

The above will add your user to the wheel group, allowing use of sudo to execute commands as root for administrative tasks like updating software. If you're planning to experiment with packaging and distributing your own software, append shedmake to the list of groups for your user.

Now, type exit to log out of your session as root and log in as your new user. From here on we'll assume you're logged in as a user with normal privileges.

Installing Updates

Before proceeding, it's a good idea to check for updates to Shedbuilt's included software, as this guide will assume you're using the latest available. Do so with a couple invocations of Shedbuilt's trivial package management tool, shedmake:

# sudo shedmake update-all
# sudo shedmake upgrade-all

If one or more of the upgraded packages requires a reboot, you'll be prompted to do so.