Raspberry Pi: Difference between revisions

From Alpine Linux
(Remove link to outdated Pi ZeroW specific page which candidate for removal)
Tag: Manual revert
(added camera_auto_detect=1 option)
 
(18 intermediate revisions by 3 users not shown)
Line 1: Line 1:
{{warning | 11 Feb 2021 - There is currently a known bug upstream <br />[https://github.com/raspberrypi/firmware/issues/1529 kernel/initramfs cannot be loaded from subdirectory with same name as volume label]. Since the kernel is installed to <code>boot/</code>, you must not use a label named <code>boot</code> for the fat32 partition. }}
{{TOC right}}
{{TOC right}}


This tutorial explains how to install Alpine Linux on a Raspberry Pi. Alpine Linux will be installed in [[Installation#Diskless_Mode|diskless mode]], hence, [[Alpine local backup|Alpine Local Backup (lbu)]] is required to save modifications between reboots.
This page explains how to install and use Alpine Linux on Raspberry Pi.  


For scenarios where there is not expected to be significant changes to disk after setup (like running a static HTTP server), this is likely preferable, as running the entire system from memory will improve performance (by avoiding the slow SD card) and improve the SD card life (by reducing the writes to the card, as all logging will happen in RAM). Diskless installations still allow you to install packages, save local files, and tune the system to your needs.
For scenarios where there is not expected to be significant changes to disk after setup (like running a static HTTP server), [[Diskless Mode|diskless mode]] is preferable, as running the entire system from memory will improve performance (by avoiding the slow SD card) and improve the SD card life (by reducing the writes to the card, as all logging will happen in RAM). Use [[Alpine local backup|Alpine Local Backup (lbu)]] utility to install packages, save local files, and tune the system.


If any of the following apply, then installation in [[Classic install or sys mode on Raspberry Pi|sys-mode installation]] is likely more appropriate.
[[Classic install or sys mode on Raspberry Pi|sys-mode installation]] is more appropriate for the following use cases:


* There will be constant changes to the disk after initial setup (for example, if you expect people to login and save files to their home directories)
* There will be constant changes to the disk after initial setup (for example, if you expect people to login and save files to their home directories)
Line 14: Line 12:
* Plan to install kernel modules (such as ZFS)
* Plan to install kernel modules (such as ZFS)


== Compability list ==
== Compatibility list ==
As of Alpine 3.19:
* '''armhf''' (defconfig bcmrpi) - Raspberry Pi 1, Zero, ZeroW, cm1
* '''armv7''' (defconfig bcm2709) - Raspberry Pi 2, 3, 3+, Zero2W, cm3, cm3+
* '''aarch64''' (defconfig bcm2711) - Raspberry Pi 3, 3+, 4, 400, Zero2W, cm3, cm3+, cm4, 5


== Preparation ==
Refer to the information regarding Raspberry Pi models in the below table when choosing image/file to download from [https://alpinelinux.org/downloads/ Downloads] page for your device. [[Installation#Verifying_downloaded_image|Verify]] the downloaded image before proceeding further.
{{:Include:Architecture support matrix}}


# [https://alpinelinux.org/downloads/ Download] the Alpine for Raspberry Pi tarball. Use the compability list above when choosing image/file to download.
== Preparing for the installation==
# [[Create_a_Bootable_Device#Manually_copying_Alpine_files|Create a bootable FAT32 partition on your SD card.]] The partitioning and formatting part of the instructions on the linked page could be done using a graphical partitioning tool such as [https://en.wikipedia.org/wiki/GNOME_Disks gnome-disks], just make sure the partition type is <code>W95 FAT32 (LBA)</code>. (The current type can be found in the "Type" column in the output of <code>fdisk -l</code>.)
# Extract the tarball to the root of the bootable FAT32 partition.


To setup a headless system, a bootstrapping configuration overlay file [https://github.com/macmpi/alpine-linux-headless-bootstrap  headless.apkovl.tar.gz] may be added to enable basic networking, so that following configuration steps can be performed under <code>ssh</code>. Pi Zero may be configured with simple USB ethernet-gadget networking with another computer sharing its internet connection.
SD card based install media can easily be generated with few clicks using [https://www.raspberrypi.com/news/raspberry-pi-imager-imaging-utility/ Raspberry Pi Imager tool] on Linux/macOS/Windows. In Alpine linux, install the {{pkg|rpi-imager}} package and launch the tool: {{Cmd|rpi-imager}}
Follow the prompts to create install media on sd-card. When using this tool, there is no need to partition and format as the tool does everything and creates the sd card based install media. Proceed to [[#Installation|Installation]], if no further customization is required.


It is recommended to create a '''usercfg.txt''' file on boot partition to configure low-level system settings, as '''config.txt''' may be replaced during bootloader/system upgrades: details can be found [https://www.raspberrypi.com/documentation/computers/config_txt.html here].<br>
=== Manual method ===
However, note some [https://www.raspberrypi.com/documentation/computers/config_txt.html#include settings] can only be set in '''config.txt''', and will have no effect when specified in '''usercfg.txt''' (e.g. <code>gpu_mem</code>). Some interesting values include:
 
* To enable the UART console: <code>enable_uart=1</code>
Alternatively, image may be downloaded, and media formatted and prepared as per below:
* To enable audio: <code>dtparam=audio=on</code>
* [https://alpinelinux.org/downloads/ Download] the Alpine for Raspberry Pi tarball. Use the compability list above when choosing image/file to download.
* [[Create_a_Bootable_Device#Manually_copying_Alpine_files|Create a bootable FAT32 partition on your SD card.]] The partitioning and formatting part of the instructions on the linked page could be done using a graphical partitioning tool such as [https://en.wikipedia.org/wiki/GNOME_Disks gnome-disks], just make sure the partition type is <code>W95 FAT32 (LBA)</code>. (The current type can be found in the "Type" column in the output of <code>fdisk -l</code>.)
*: {{warning |Due to an upstream [https://github.com/raspberrypi/firmware/issues/1529 bug], kernel/initramfs cannot be loaded from subdirectory with same name as volume label. Since kernel is installed to <code>boot/</code> folder in Alpine Linux, do not use  label <code>boot</code> for the fat32 partition.}}
* Extract the tarball to the root of the bootable FAT32 partition.
* It is recommended to create a '''usercfg.txt''' file on boot partition to configure low-level system settings, as '''config.txt''' may be replaced during bootloader/system upgrades: details can be found [https://www.raspberrypi.com/documentation/computers/config_txt.html here]. However, some [https://www.raspberrypi.com/documentation/computers/config_txt.html#include settings] can only be set in '''config.txt''', and will have no effect when specified in '''usercfg.txt''' (e.g. <code>gpu_mem</code>). Some interesting values include:{{Cat|usercfg.txt|<nowiki>
enable_uart=1 # To enable the UART console:
dtparam=audio=on # To enable audio </nowiki>}}
* By default system will use legacy video driver: some [https://www.raspberrypi.com/documentation/computers/legacy_config_txt.html#legacy-video-options options] may be used to adjust displays modes (e.g. if you see black edges around your screen after booting the Pi, you can add <code>disable_overscan=1</code>). Alternatively Linux DRM-KMS driver may be used (see below).
* By default system will use legacy video driver: some [https://www.raspberrypi.com/documentation/computers/legacy_config_txt.html#legacy-video-options options] may be used to adjust displays modes (e.g. if you see black edges around your screen after booting the Pi, you can add <code>disable_overscan=1</code>). Alternatively Linux DRM-KMS driver may be used (see below).
* If you plan to install on a Pi Compute Module 4 with I/O board, you may need to add: <code>otg_mode=1</code>
* If you plan to install on a Pi Computer Module 4 with I/O board, you may need to add: <code>otg_mode=1</code>
* Pi Zero may be configured as simple USB serial-gadget or ethernet-gadget networking with another computer sharing its internet connection.
* For headless use, use the following parameters to maximize available memory (32 megs is required for the rpi bootloader):<code>gpu_mem=32</code>


Recent versions include Broadcom firmware files. If you're using an older Alpine version, see [[#Wireless_support_with_older_Alpine_images|section below]].
=== Headless pi ===


== Installation ==
To setup a headless system, a bootstrapping configuration overlay file [https://github.com/macmpi/alpine-linux-headless-bootstrap  headless.apkovl.tar.gz] may be added to the sd card based Install media. To enable wifi, create a file {{Path|wpa_supplicant.conf}} in the install media as follows:{{Cat|wpa_supplicant.conf|<nowiki>country=FR
 
network={
key_mgmt=WPA-PSK
ssid="mySSID"
psk="myPassPhrase"
}
</nowiki>}}
 
Alternately, use <code>wpa_passphrase</code> utility from {{pkg|wpa_supplicant}} package to create the encrypted version of the above file {{Path|wpa_supplicant.conf}} as follows: {{Cmd| wpa_passphrase 'mySSID' 'myPassPhrase' > wpa_supplicant.conf}} and place it on the install media.
 
With the above setup, following Installation steps can be performed remotely using <code>ssh</code>.


Follow these steps to install Alpine Linux in Diskless Mode:
* Use {{Codeline|nmap -v -sn 192.168.1.0/24}} to find the ip of your pi.
* Refer [https://github.com/macmpi/alpine-linux-headless-bootstrap author's website] for other options.


== Installation ==
{{Seealso|Classic install or sys mode on Raspberry Pi}}
Follow these steps to install Alpine Linux in [[Diskless Mode]]:
# Insert the SD card into the Raspberry Pi and power it on
# Insert the SD card into the Raspberry Pi and power it on
# Login into the Alpine system as root.  Leave the password empty.
# Login into the Alpine system as root.  Leave the password empty.
# Check the current date and time by issuing <code>date</code>. Correct if necessary by issuing <code>date -s YYYYMMDDhhmm</code>.
# Type <code>setup-alpine</code>
# Type <code>setup-alpine</code>
# Once the installation is complete, commit the changes by typing <code>lbu commit -d</code>
# Once the installation is complete, commit the changes by typing <code>lbu commit -d</code>
Line 64: Line 82:


=== Linux Kernel Graphics Modes ===
=== Linux Kernel Graphics Modes ===
By default system configuration will use legacy video driver: this driver has some limitations and is lacking support.<br>
By default system configuration will use legacy video driver: this driver has some limitations and is lacking support.<br>
It is recommended to enable Linux DRM-KMS driver by adding the following to '''usercfg.txt''':
It is recommended to enable Linux DRM-KMS driver by adding the following to '''usercfg.txt''':
Line 84: Line 103:


=== Wireless drivers ===
=== Wireless drivers ===
As of Alpine 3.17, Wifi and Bluetooth drivers are available within install image: they are part of <code>linux-firmware-brcm</code> (and linked dependencies).<br>
Since kernel 6.1.25 (i.e. Alpine 3.18), onboard bluetooth is enabled & autoprobed by default (it may be disabled by setting [https://github.com/raspberrypi/rpi-firmware/tree/master/overlays krnbt] off).
== Troubleshooting ==
<code>raspinfo</code> utility can be used as a first step to diagnose issues: it will make a log report of essential Pi system configuration, and is often used as a reference to submit questions or bug reports within Raspberry Pi community (Forums, Github, etc).<br>
It can be installed with <code>raspberrypi-utils-raspinfo</code> subpackage.


=== Long boot time when running headless ===
As of Alpine 3.17, Wifi and Bluetooth drivers are available within install image: they are part of <code>linux-firmware-brcm</code> (and linked dependencies). Since kernel 6.1.25 (i.e. Alpine 3.18), onboard bluetooth is enabled & autoprobed by default. This may be disabled by setting [https://github.com/raspberrypi/rpi-firmware/tree/master/overlays krnbt] off).


If no peripherals are connected, the system might hang for an exceptionally long period of time while it attempts to accumulate entropy.
=== Picam ===


If this is the case, simply plugging in any USB device should work around this issue, since it increases the amount of entropy available to the kernel via interrupts.
The working of picam has been tested in [[Classic install or sys mode on Raspberry Pi|sys mode]] only with Pi Zero 2 W model.


=== apk indicating 'No space left on device' ===
# Upgrade to [[Repositories#Upgrading_to_edge|edge]] version as {{pkg|rpicam-apps}} package is not yet supported in v3.21.
# Setup eudev as device manager:{{Cmd|# setup-devd udev}}
# Add <Code>camera_auto_detect=1</Code> option to the user config file {{Path|/boot/usercfg.txt}}
# Install the package {{pkg|rpicam-apps}} available in the [[Repositories#Testing|testing]] repository.
# Due to bug {{Issue|16911}}, change the permission after every reboot as follows:{{Cmd|$doas chmod 666 /dev/dma_heap/*}}
# Test the picam by the command {{Cmd|$libcamera-hello --list-cameras}}


Note some models of the Raspberry Pi such as the 3A+ only have 512M of RAM, which on fresh Alpine deployment will only leave around 200M for tmpfs root. It's important to keep this limitation in mind when using these boards.
== Loopback image with overlayfs ==
 
=== Clock-related error messages ===
 
During the booting time, you might notice errors related to the hardware clock.  Many Raspberry Pi does not have a hardware clock, thus you need to disable the hwclock daemon and enable swclock:
 
{{cmd|rc-update add swclock boot    # enable the software clock
rc-update del hwclock boot    # disable the hardware clock}}
 
== Persistent storage ==
=== Traditional disk-based (sys) installation ===
{{Merge|Classic install or sys mode on Raspberry Pi|There's an existing page for sys-installations on RasPi.}}
 
It is also possible to switch to a fully disk-based installation. This is not yet formally supported, but can be done somewhat manually. This frees all the memory otherwise needed for the root filesystem, allowing more installed packages.
 
Split your SD card into two partitions: the FAT32 boot partition described above (in this example it'll be <code>mmcblk0p1</code>) , and a second partition to hold the root filesystem (here it'll be <code>mmcblk0p2</code>). Boot and configure your diskless system as above, then create a root filesystem:
 
{{cmd|apk add {{pkg|e2fsprogs|arch=a*}}
mkfs.ext4 /dev/mmcblk0p2}}
 
Now do a disk install via a mountpoint. The <code>setup-disk</code> script will give some errors about syslinux/extlinux, but you can ignore them.
The Raspberry Pi doesn't need them to boot.
 
{{cmd|<nowiki>mkdir /stage
mount /dev/mmcblk0p2 /stage
setup-disk -o /media/mmcblk0p1/MYHOSTNAME.apkovl.tar.gz /stage
# (ignore errors about syslinux/extlinux)</nowiki>}}
 
Add a line to <code>/stage/etc/fstab</code> to mount the Pi's boot partition again:
 
{{cmd|/dev/mmcblk0p1 /media/mmcblk0p1 vfat defaults 0 0}}
 
Now add a <code>root=/dev/mmcblk0p2</code> parameter to the Pi's boot command line, either <code>cmdline-rpi2.txt</code> or <code>cmdline-rpi.txt</code> depending on model:
 
{{cmd|<nowiki>mount -o remount,rw /media/mmcblk0p1
sed -i '$ s/$/ root=\/dev\/mmcblk0p2/' /media/mmcblk0p1/cmdline-rpi2.txt</nowiki>}}
 
You might also consider <code>overlaytmpfs=yes</code> here, which will cause the underlying SD card root filesystem to be mounted read-only, with an overlayed tmpfs for modifications which will be discarded at shutdown.
 
N.B. <b>the contents of /boot will be ignored when the Pi boots</b>. It will use the kernel, initramfs, and modloop images from the FAT32 boot partition. To update the kernel, initfs or modules, you will need to manually (generate and) copy these to the boot partition or you could use bind mount, in which case,
copying the files to boot partition manually, is not needed.
 
{{cmd|<nowiki>echo /media/mmcblk0p1/boot /boot none defaults,bind 0 0 >> /etc/fstab</nowiki>}}
 
=== Loopback image with overlayfs ===


When you install Alpine in diskless mode, the entire system is loaded into memory at boot. If you want additional storage (for example, if you need more space than offered by your RAM) we need to create loop-back storage onto the SD card mounted with overlayfs.
When you install Alpine in diskless mode, the entire system is loaded into memory at boot. If you want additional storage (for example, if you need more space than offered by your RAM) we need to create loop-back storage onto the SD card mounted with overlayfs.
Line 168: Line 142:
mkdir /media/persist  
mkdir /media/persist  
mount -a}}
mount -a}}
{{Note|Overlay workdir needs to be an empty directory on the same filesystem mount as the upper directory. So each overlay must use its own workdir.}}


Make the overlay folders, we are using the /usr directory here, but you can use /home or anything else.  
Make the overlay folders, we are using the /usr directory here, but you can use /home or anything else.  
{{Warning|Overlay workdir needs to be an empty directory on the same filesystem mount as the upper directory. So each overlay must use its own workdir.}}
{{cmd|mkdir /media/persist/usr  
{{cmd|mkdir /media/persist/usr  
mkdir /media/persist/.work_usr  
mkdir /media/persist/.work_usr  
Line 195: Line 168:


== Netboot ==
== Netboot ==
=== Netbooting Raspberry Pi 4 ===


The Raspberry Pi 4 bootloader can be configured to boot from the network [https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#raspberry-pi-4-bootloader-configuration]. Configure the bootloader with at least
The Raspberry Pi 4 bootloader can be configured to boot from the network [https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#raspberry-pi-4-bootloader-configuration]. Configure the bootloader with at least
Line 233: Line 204:


With the above configured the Raspberry Pi 4 should be able to boot from the network without an SD card.
With the above configured the Raspberry Pi 4 should be able to boot from the network without an SD card.
== Enable the Serial Console ==
Besides having <code>enable_uart=1</code> in ''usercfg.txt'', the kernel command-line option <var>console</var> needs to be changed to <code>console=serial0,115200</code> in ''cmdline.txt''.
From a Linux desktop, connect to it with something like this:
{{cmd|cu -l /dev/ttyUSB0 -s 115200}}
== Troubleshooting ==
<code>raspinfo</code> utility from the {{Pkg|raspberrypi-utils-raspinfo}} package can be used as a first step to diagnose issues: it will make a log report of essential Pi system configuration, and is often used as a reference to submit questions or bug reports within Raspberry Pi community (Forums, Github, etc).
After booting, you may find less system memory available than you expect.  Currently the Pi requires a minimum of 32 megs of memory for the gpu, to boot unless you have the cut down boot loader installed, in which case you can use 16.  However, you may find more gpu memory is still being used, even if you configure it for less, if you enable audio or camera support.  To find out how your system is actually split, use <Code>vcgencmd</Code> utility from the {{pkg|raspberrypi-utils-vcgencmd}} package as follows:{{Cmd|<nowiki># vcgencmd get_mem gpu
# vcgencmd get_mem arm</nowiki>}}
=== Long boot time when running headless ===
If no peripherals are connected, the system might hang for an exceptionally long period of time while it attempts to accumulate entropy.
If this is the case, simply plugging in any USB device should work around this issue, since it increases the amount of entropy available to the kernel via interrupts.
=== apk indicating 'No space left on device' ===
Note some models of the Raspberry Pi such as the 3A+ only have 512M of RAM, which on fresh Alpine deployment will only leave around 200M for tmpfs root. It's important to keep this limitation in mind when using these boards.
=== Clock-related error messages ===
During the booting time, you might notice errors related to the hardware clock.  Many Raspberry Pi do not have a hardware clock, or may have one without battery, in which case the behaviour depends on whether you physically cut power or not.
Also, <code>setup-alpine</code> will adapt the installation to the type of Raspberry Pi you use, which means for example that on a RPI5, you will see <code>hwclock></code> service, whereas on a RPI4 it will use <code>swclock</code>. In doubt, make sure to do the installation on the target hardware.
If you still experience clock errors, add the following line to '''/etc/chrony/chrony.conf''':
<code>makestep 0.1 3</code>


=== Wireless support with older Alpine images ===
=== Wireless support with older Alpine images ===
Line 249: Line 255:
   cp firmware-nonfree/brcm/* /mnt/sdcard/firmware/brcm
   cp firmware-nonfree/brcm/* /mnt/sdcard/firmware/brcm


== Enable the Serial Console ==
=== Fileystem for boot partition ===
Besides having <code>enable_uart=1</code> in ''usercfg.txt'', the kernel command-line option <var>console</var> needs to be changed to <code>console=serial0,115200</code> in ''cmdline.txt''.
 
From a Linux desktop, connect to it with something like this:


{{cmd|cu -l /dev/ttyUSB0 -s 115200}}
If you are trapped at the dreaded rainbow screen, with the green led blinking a few times in a row, repeatedly, check the boot partition type.


== See Also ==
The rpi2 require '''fat32''' for the boot partition, NOT '''fat16'''.  Use linux fdisk to set the boot partition type as "c" (for fat32/lba) and set the '''lba''' and '''boot''' flags for the partition as suggested.  Create the boot partition filesystem as fat32 with:{{Cmd|mkdosfs -F 32 /dev/sdX1}}


== See also ==
* [[Classic install or sys mode on Raspberry Pi]] - a variant.
* [[Classic install or sys mode on Raspberry Pi]] - a variant.
* [[Raspberry Pi 3 - Setting Up Bluetooth]]
* [[Raspberry Pi 3 - Setting Up Bluetooth]]

Latest revision as of 13:14, 14 February 2025

This page explains how to install and use Alpine Linux on Raspberry Pi.

For scenarios where there is not expected to be significant changes to disk after setup (like running a static HTTP server), diskless mode is preferable, as running the entire system from memory will improve performance (by avoiding the slow SD card) and improve the SD card life (by reducing the writes to the card, as all logging will happen in RAM). Use Alpine Local Backup (lbu) utility to install packages, save local files, and tune the system.

sys-mode installation is more appropriate for the following use cases:

  • There will be constant changes to the disk after initial setup (for example, if you expect people to login and save files to their home directories)
  • Logs should persists across reboots
  • Plan to install packages which consume more space than can be loaded into RAM
  • Plan to install kernel modules (such as ZFS)

Compatibility list

Refer to the information regarding Raspberry Pi models in the below table when choosing image/file to download from Downloads page for your device. Verify the downloaded image before proceeding further.

Alpine Linux Hardware Support Matrix
Architecture Port Description Since
x86 x86 32 bit i686 compatible (or later) CPUs with at least CMOV and SSE2 All
x86_64 AMD64 compatible 64-bit x86 instruction set All
ARM armhf 32 bit ARM with hard-float ABI - for ARMv6 devices- Raspberry Pi 1, Zero, ZeroW, cm1 (defconfig bcmrpi) v3.0
armv7 32 bit ARM - for ARMv7 devices - Raspberry Pi 2, 3, 3+, Zero2W, cm3, cm3+ (defconfig bcm2709) v3.9
aarch64 64 bit ARM - for ARMv8+ devices - Raspberry Pi 3, 3+, 4, 400, Zero2W, cm3, cm3+, cm4, 5 (defconfig bcm2711) v3.5
PowerPC ppc64le 64 bit PowerPC (little-endian) mostly for POWER8 and POWER9 v3.6
IBM System Z s390x IBM Z mainframes, especially IBM Z and IBM LinuxONE (z196 minimum) v3.6
RISC V riscv64 64 bit RISC V v3.20
LoongArch loongarch64 64 bit LoongArch v3.21

Preparing for the installation

SD card based install media can easily be generated with few clicks using Raspberry Pi Imager tool on Linux/macOS/Windows. In Alpine linux, install the rpi-imager package and launch the tool:

rpi-imager

Follow the prompts to create install media on sd-card. When using this tool, there is no need to partition and format as the tool does everything and creates the sd card based install media. Proceed to Installation, if no further customization is required.

Manual method

Alternatively, image may be downloaded, and media formatted and prepared as per below:

  • Download the Alpine for Raspberry Pi tarball. Use the compability list above when choosing image/file to download.
  • Create a bootable FAT32 partition on your SD card. The partitioning and formatting part of the instructions on the linked page could be done using a graphical partitioning tool such as gnome-disks, just make sure the partition type is W95 FAT32 (LBA). (The current type can be found in the "Type" column in the output of fdisk -l.)
    Warning: Due to an upstream bug, kernel/initramfs cannot be loaded from subdirectory with same name as volume label. Since kernel is installed to boot/ folder in Alpine Linux, do not use label boot for the fat32 partition.

  • Extract the tarball to the root of the bootable FAT32 partition.
  • It is recommended to create a usercfg.txt file on boot partition to configure low-level system settings, as config.txt may be replaced during bootloader/system upgrades: details can be found here. However, some settings can only be set in config.txt, and will have no effect when specified in usercfg.txt (e.g. gpu_mem). Some interesting values include:

    Contents of usercfg.txt

    enable_uart=1 # To enable the UART console: dtparam=audio=on # To enable audio
  • By default system will use legacy video driver: some options may be used to adjust displays modes (e.g. if you see black edges around your screen after booting the Pi, you can add disable_overscan=1). Alternatively Linux DRM-KMS driver may be used (see below).
  • If you plan to install on a Pi Computer Module 4 with I/O board, you may need to add: otg_mode=1
  • Pi Zero may be configured as simple USB serial-gadget or ethernet-gadget networking with another computer sharing its internet connection.
  • For headless use, use the following parameters to maximize available memory (32 megs is required for the rpi bootloader):gpu_mem=32

Headless pi

To setup a headless system, a bootstrapping configuration overlay file headless.apkovl.tar.gz may be added to the sd card based Install media. To enable wifi, create a file wpa_supplicant.conf in the install media as follows:

Contents of wpa_supplicant.conf

country=FR network={ key_mgmt=WPA-PSK ssid="mySSID" psk="myPassPhrase" }

Alternately, use wpa_passphrase utility from wpa_supplicant package to create the encrypted version of the above file wpa_supplicant.conf as follows:

wpa_passphrase 'mySSID' 'myPassPhrase' > wpa_supplicant.conf

and place it on the install media.

With the above setup, following Installation steps can be performed remotely using ssh.

  • Use nmap -v -sn 192.168.1.0/24 to find the ip of your pi.
  • Refer author's website for other options.

Installation

See also: Classic install or sys mode on Raspberry Pi

Follow these steps to install Alpine Linux in Diskless Mode:

  1. Insert the SD card into the Raspberry Pi and power it on
  2. Login into the Alpine system as root. Leave the password empty.
  3. Check the current date and time by issuing date. Correct if necessary by issuing date -s YYYYMMDDhhmm.
  4. Type setup-alpine
  5. Once the installation is complete, commit the changes by typing lbu commit -d

Type reboot to verify that the installation was indeed successful.

Post Installation

Update the System

After installation, make sure your system is up-to-date:

apk update apk upgrade

Don't forget to save the changes:

lbu commit -d

Note: this does not upgrade the kernel. In order to upgrade the kernel, a full upgrade of the Alpine Linux version must be performed as described in upgrading Alpine Linux for removable media.

Linux Kernel Graphics Modes

By default system configuration will use legacy video driver: this driver has some limitations and is lacking support.
It is recommended to enable Linux DRM-KMS driver by adding the following to usercfg.txt: 

# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2

# Don't have the firmware create an initial video= setting in cmdline.txt.
# Use the kernel's default instead.
disable_fw_kms_setup=1

Note: This overlay disables legacy video options.

Install the Mesa drivers (Pi4 and Pi5):

apk add mesa-dri-gallium

Then reboot:

lbu_commit -d; reboot

Wireless drivers

As of Alpine 3.17, Wifi and Bluetooth drivers are available within install image: they are part of linux-firmware-brcm (and linked dependencies). Since kernel 6.1.25 (i.e. Alpine 3.18), onboard bluetooth is enabled & autoprobed by default. This may be disabled by setting krnbt off).

Picam

The working of picam has been tested in sys mode only with Pi Zero 2 W model.

  1. Upgrade to edge version as rpicam-apps package is not yet supported in v3.21.
  2. Setup eudev as device manager:

    # setup-devd udev

  3. Add camera_auto_detect=1 option to the user config file /boot/usercfg.txt
  4. Install the package rpicam-apps available in the testing repository.
  5. Due to bug #16911, change the permission after every reboot as follows:

    $doas chmod 666 /dev/dma_heap/*

  6. Test the picam by the command

    $libcamera-hello --list-cameras

Loopback image with overlayfs

When you install Alpine in diskless mode, the entire system is loaded into memory at boot. If you want additional storage (for example, if you need more space than offered by your RAM) we need to create loop-back storage onto the SD card mounted with overlayfs.

First, make the SD card writable again and change fstab to always do so:

mount /media/mmcblk0p1 -o rw,remount sed -i 's/vfat\ ro,/vfat\ rw,/' /etc/fstab

Create the loop-back file, this example is 1 GB:

dd if=/dev/zero of=/media/mmcblk0p1/persist.img bs=1024 count=0 seek=1048576

Install the ext utilities:

apk add e2fsprogs

Format the loop-back file:

mkfs.ext4 /media/mmcblk0p1/persist.img

Mount the storage:

echo "/media/mmcblk0p1/persist.img /media/persist ext4 rw,relatime,errors=remount-ro 0 0" >> /etc/fstab mkdir /media/persist mount -a

Note: Overlay workdir needs to be an empty directory on the same filesystem mount as the upper directory. So each overlay must use its own workdir.

Make the overlay folders, we are using the /usr directory here, but you can use /home or anything else.

mkdir /media/persist/usr mkdir /media/persist/.work_usr echo "overlay /usr overlay lowerdir=/usr,upperdir=/media/persist/usr,workdir=/media/persist/.work_usr 0 0" >> /etc/fstab mount -a

Your /etc/fstab should look something like this:

/dev/cdrom /media/cdrom iso9660 noauto,ro 0 0 /dev/usbdisk /media/usb vfat noauto,ro 0 0 /dev/mmcblk0p1 /media/mmcblk0p1 vfat rw,relatime,fmask=0022,dmask=0022,errors=remount-ro 0 0 /media/mmcblk0p1/persist.img /media/persist ext4 rw,relatime,errors=remount-ro 0 0 overlay /usr overlay lowerdir=/usr,upperdir=/media/persist/usr,workdir=/media/persist/.work_usr 0 0

Now commit the changes: (optionally remove the e2fsprogs, but it does contain repair tools)

lbu_commit -d

Remember, with this setup if you install things and you have done this overlay for /usr, you must not commit the 'apk add', otherwise, while it boots it will try and install it to memory, not to the persistent storage.

If you do want to install something small at boot, you can use apk add and lbu commit -d.

If it is something a bit bigger, then you can use apk add but then not commit it. It will be persistent (in /user), but be sure to check everything you need is in that directory and not in folders you have not made persistent.

Netboot

The Raspberry Pi 4 bootloader can be configured to boot from the network [1]. Configure the bootloader with at least

BOOT_ORDER=0xf142 TFTP_PREFIX=1

and optionally also

TFTP_IP=x.x.x.x

where x.x.x.x is the IP address of your TFTP server.

If not configuring TFTP_IP in the bootloader, you'll need to configure your DHCP server to advertise the TFTP server IP address. This varies depending on your DHCP server; use the following details if applicable:

  1. Vendor class: PXEClient:Arch:00000:UNDI:002001
  2. Filename: /

The minimal set of files that your TFTP server needs to host are:

  1. bcm2711-rpi-4-b.dtb (from raspberrypi/firmware/master/boot/bcm2711-rpi-4-b.dtb)
  2. cmdline.txt (see below)
  3. config.txt (see below)
  4. fixup4.dat (from raspberrypi/firmware/master/boot/fixup4.dat, alternatively fixup4cd.dat for the cut down version)
  5. initramfs-rpi4 (from alpine/edge/releases/aarch64/netboot/initramfs-rpi4)
  6. start4.elf (from raspberrypi/firmware/master/boot/start4.elf, alternatively start4cd.elf for the cut down version)
  7. vmlinuz-rpi4 (from alpine/edge/releases/aarch64/netboot/vmlinuz-rpi4)

config.txt:

[pi4] kernel=vmlinuz-rpi4 initramfs initramfs-rpi4 arm_64bit=1

cmdline.txt:

modules=loop,squashfs console=ttyAMA0,115200 ip=dhcp alpine_repo=http://dl-cdn.alpinelinux.org/alpine/edge/main modloop=http://dl-cdn.alpinelinux.org/alpine/edge/releases/aarch64/netboot/modloop-rpi4

Instead of using the http://dl-cdn.alpinelinux.org/alpine/edge/releases/aarch64/netboot/ base URL above, pinning to a specific point in time is preferred. Raspberry Pi 4 netboot files are available from https://dl-cdn.alpinelinux.org/alpine/edge/releases/aarch64/netboot-20230329/ onward.

With the above configured the Raspberry Pi 4 should be able to boot from the network without an SD card.

Enable the Serial Console

Besides having enable_uart=1 in usercfg.txt, the kernel command-line option console needs to be changed to console=serial0,115200 in cmdline.txt.

From a Linux desktop, connect to it with something like this:

cu -l /dev/ttyUSB0 -s 115200

Troubleshooting

raspinfo utility from the raspberrypi-utils-raspinfo package can be used as a first step to diagnose issues: it will make a log report of essential Pi system configuration, and is often used as a reference to submit questions or bug reports within Raspberry Pi community (Forums, Github, etc).

After booting, you may find less system memory available than you expect. Currently the Pi requires a minimum of 32 megs of memory for the gpu, to boot unless you have the cut down boot loader installed, in which case you can use 16. However, you may find more gpu memory is still being used, even if you configure it for less, if you enable audio or camera support. To find out how your system is actually split, use vcgencmd utility from the raspberrypi-utils-vcgencmd package as follows:

# vcgencmd get_mem gpu # vcgencmd get_mem arm

Long boot time when running headless

If no peripherals are connected, the system might hang for an exceptionally long period of time while it attempts to accumulate entropy.

If this is the case, simply plugging in any USB device should work around this issue, since it increases the amount of entropy available to the kernel via interrupts.

apk indicating 'No space left on device'

Note some models of the Raspberry Pi such as the 3A+ only have 512M of RAM, which on fresh Alpine deployment will only leave around 200M for tmpfs root. It's important to keep this limitation in mind when using these boards.

Clock-related error messages

During the booting time, you might notice errors related to the hardware clock. Many Raspberry Pi do not have a hardware clock, or may have one without battery, in which case the behaviour depends on whether you physically cut power or not.

Also, setup-alpine will adapt the installation to the type of Raspberry Pi you use, which means for example that on a RPI5, you will see hwclock> service, whereas on a RPI4 it will use swclock. In doubt, make sure to do the installation on the target hardware.

If you still experience clock errors, add the following line to /etc/chrony/chrony.conf:

makestep 0.1 3

Wireless support with older Alpine images

In Alpine 3.14, the WiFi drivers for the Raspberry Pi were moved from linux-firmware-brcm to the linux-firmware-cypress package (source?). Since the images seem to be an outdated version of the former, Wi-Fi will work during installation, but after the first update it will break. Use the ethernet interface to download the required packages:

apk add linux-firmware-cypress

And reboot.

If you need Wi-Fi, you'll need to download the latest Broadcom drivers to your SD card. (Replace /mnt/sdcard with the correct mount point.) 

 git clone --depth 1 https://github.com/RPi-Distro/firmware-nonfree.git
 cp firmware-nonfree/brcm/* /mnt/sdcard/firmware/brcm

Fileystem for boot partition

If you are trapped at the dreaded rainbow screen, with the green led blinking a few times in a row, repeatedly, check the boot partition type.

The rpi2 require fat32 for the boot partition, NOT fat16. Use linux fdisk to set the boot partition type as "c" (for fat32/lba) and set the lba and boot flags for the partition as suggested. Create the boot partition filesystem as fat32 with:

mkdosfs -F 32 /dev/sdX1

See also

Retrieved from "https://wiki.alpinelinux.org/w/index.php?title=Raspberry_Pi&oldid=29017"