Create a Bootable Device: Difference between revisions

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This page is about creating a customizable boot device. The creation (flashing) of a default (iso) installation media is covered on the [[Installation#Flashing_.28direct_data_writing.29_the_installation_image-file_onto_a_device_or_media|Installation]] page.
This page is about creating directly customizable boot devices. If you are looking for instructions on creating (flashing) read-only (iso9660 "CD" filesystem) images onto installation media, see the [[Installation#Flashing_.28direct_data_writing.29_the_installation_image-file_onto_a_device_or_media|Installation]] page instead.


A customizable Alpine Linux boot medium is basically an Alpine system installed to the device in '''diskless''' or '''data''' disk-mode.
A directly customizable Alpine Linux boot medium is basically an Alpine system in '''[[Installation#Diskless_Mode|diskless]]''' or '''[[Installation#Data_Disk_Mode|data]]''' disk-mode installed to (and booting from) a device with a writable filesystem. It allows to also upgrade the kernel with its modules and firmware that is used to boot the system with the <code>[[Alpine_Linux_package_management#Upgrading_.22diskless.22_and_.22data.22_disk_mode_installs|update-kernel]]</code> script.


As long as the device remains writable, the local configs (.apkovl) and the package cache may also be stored on the same device.
The more general local customizations, the configs (.apkovl) and the package cache, may of course also be stored on the same device, as long as the hardware is not being set to be write-locked by a hardware switch.


   
   
= Requirements =
= Requirements =


In order to follow this document, you will need:
* An Alpine Linux CD-ROM or an .iso file containing the desired Alpine release ([https://alpinelinux.org/downloads/ Download]).
 
* A device like an USB drive (flash, external HD, card reader, etc.) or a CF "CompactFlash", or SDcard.
* An Alpine Linux CD-ROM or an .iso file containing an Alpine release ([https://alpinelinux.org/downloads/ Download]).
* A USB drive (flash, external HD, card reader, etc.)


= Using setup-bootable  =
= Using setup-bootable  =


The preferable method to create a custom bootable device now is to follow the [[Installation]] for a '''diskless''' or '''data''' mode system on the device, and use the <code>[[Alpine_setup_scripts#setup-bootable|setup-bootable]]</code> script to make the device bootable.
This is now the preferable method to create a directly customizable bootable device.


It consists an [[Installation]] of a '''diskless''' or '''data''' mode system with configs and package cache on the target device, and using the <code>[[Alpine_setup_scripts#setup-bootable|setup-bootable]]</code> script to make the device bootable.


= Manually copying Alpine files =
= Manually copying Alpine files =


This process applies to Alpine Linux 1.9.0 or later.
If you can't/won't use '''setup-bootable''', you can manually create a customizable (writable) USB boot device instead.
 
=== Copying ISO/tarball contents to a USB stick ===
 
This method is written for copying files from an Alpine ISO file but also works for Alpine tarballs (.tar.gz files) with a one line tweak (see below).
 
# Install some prerequisites. (If you're not currently using Alpine Linux then you probably have these installed already, otherwise you'll have to figure out how to install them.)
#: {{Cmd|apk add dosfstools<BR>apk add syslinux}}
# Set the environment variable 'mydev' to the [https://en.wikipedia.org/wiki/Device_file device file] name of the USB stick that Alpine Linux is to be installed to:
#: {{Warning | BE SURE TO GET THIS RIGHT OR ELSE YOU COULD OVERWRITE THE WRONG DISK! }}
#: {{Cmd|<nowiki>mydev=/dev/sdU</nowiki>}}
# Make sure that the target drive's existing partitions, if any, are not mounted:
#: {{Cmd|umount -q $mydev?}}
# Copy and paste the following as a single command to wipe the target drive, create an MBR partition table, and create a single FAT32 partition (you can ignore any "Partition #1 contains a vfat signature." warning message):
#: {{Cmd|<nowiki>fdisk -w always $mydev <<EOF
  o
  n
  p
  1
  2048
  -0
  t
  0c
  a
  w
EOF</nowiki>}}
# Format the new FAT32 partition with a FAT32 filesystem:
#: {{Cmd|<nowiki>mkdosfs -F32 ${mydev}1</nowiki>}}
# Copy the [https://wiki.syslinux.org/wiki/index.php?title=Mbr syslinix executable boot code] into the bootstrap code area of the MBR boot sector (if you're not currently using Alpine Linux you may need to adjust the path to syslinux's mbr.bin file):
#: {{Cmd|<nowiki>dd bs=440 count=1 conv=notrunc if=/usr/share/syslinux/mbr.bin of=$mydev</nowiki>}}
# Install the syslinux bootloader files onto the FAT32 filesystem (ignore the "Hidden (2048) does not match sectors (62)" messages - modern systems use the partition table):
#: {{Cmd|syslinux ${mydev}1}}
# Copy the Alpine files to the FAT32 filesystem (to copy the contents of an Alpine {{Path|.tar.gz}} tarball instead of copying {{Path|/media/cdrom}}, set <code>$alpinetarball</code> to the path to the tarball and replace the 'cp' line with: <code>tar -p -s --atime-preserve --same-owner --one-top-level=/media/$mydevname -zxvf "$alpinetarball"</code>):
#: {{Cmd|<nowiki>mydevname=$(basename $mydev)1
mkdir -p /media/$mydevname
mount -t vfat ${mydev}1 /media/$mydevname
cp -aT /media/cdrom /media/$mydevname  # -T to copy hidden files
umount /media/$mydevname</nowiki>}}
# (''Optional'') Remove any .apkovl overlay files that were transferred as part of the copy process. Do this if you want an unmodified, vanilla install.
#: {{Cmd|<nowiki>mount -t vfat ${mydev}1 /media/$mydevname
rm /media/$mydevname/*.apkovl.tar.gz
umount /media/$mydevname</nowiki>}}
 
 
=== Troubleshooting ===
 
==== Wrong Device Name ====
 
If you cannot boot from the boot device and you see something like:
Mounting boot media failed.
initramfs emergency recovery shell launched. Type 'exit' to continue boot
then it is likely that the device name in {{Path|syslinux.cfg}} is wrong. You should replace the device name in this line:
append initrd=/boot/grsec.gz alpine_dev='''usbdisk''':vfat modules=loop,cramfs,sd-mod,usb-storage quiet
with the proper device name.
* For boot from USB, the device name should be 'usbdisk' (as shown above)
* For other options, you can run <code>cat /proc/partitions</code> to see the available disks (i.e. 'sda' or 'sdb')
 
==== Non-FAT32 Filesystems ====
 
===== Diskless and data mode booting =====
 
When the boot device is formatted with a filesystem other than those supported by default, the necessary initfs features need to be added to the modloop using <code>update-kernel</code>. See: [[Alpine_Linux_package_management#Upgrading_.22diskless.22_and_.22data.22_disk_mode_installs]]


{{:Include:Copying Alpine to Flash|USB stick}}
===== Sys mode booting  =====
 
Mount the boot device and edit the {{Path|syslinux.cfg}} file.
 
Then locate the "append" line, and change the <code>alpine_dev=</code> setting to match the used filesystem and add the filesystem's kernel module to the <code>modules=</code> list.
 
For example, change
append [...] alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet
to
append [...] alpine_dev=usbdisk:'''ext4''' modules=loop,cramfs,sd-mod,usb-storage''',ext4''' quiet
in the case of an ext4 formatted partition. (Or correspondingly for other filesystems, if they are supported by syslinux and the Alpine Linux kernel.)


== Finishing installation ==
== Finishing installation ==
Line 32: Line 102:


  # mount | grep /media
  # mount | grep /media
  /dev/sda1 on /media/sda1 type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro)
  /dev/sdU1 on /media/sdU1 type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro)


Create local directory on USB media to hold local APK cache (see [[Alpine_Linux_package_management#Local_Cache|APK Local Cache]] for details).
Create local directory on USB media to hold local APK cache (see [[Alpine_Linux_package_management#Local_Cache|APK Local Cache]] for details).


  # mount -o remount,rw /media/sda1
  # mount -o remount,rw /media/sdU1
  # mkdir /media/sda1/cache
  # mkdir /media/sdU1/cache
  # setup-apkcache /media/sda1/cache
  # setup-apkcache /media/sdU1/cache
  # ls -l /etc/apk/cache
  # ls -l /etc/apk/cache
  lrwxrwxrwx    1 root    root            17 Oct 19 13:16 /etc/apk/cache -> /media/sda1/cache
  lrwxrwxrwx    1 root    root            17 Oct 19 13:16 /etc/apk/cache -> /media/sdU1/cache


Now run ''setup-alpine'' and proceed until a question about local disk selection - in ''diskless'' mode we won't use any disk (ie. our bootable media files is basically untouched) and we are going to use ''sda1'' to hold our system customization.
Now run ''setup-alpine'' and proceed until a question about local disk selection - in ''diskless'' mode we won't use any disk (ie. our bootable media files is basically untouched) and we are going to use ''sdU1'' to hold our system customization.


  # setup-alpine
  # setup-alpine
  ...
  ...
  Which disk(s) would you like to use? (or '?' for help or 'none') [none]  
  Which disk(s) would you like to use? (or '?' for help or 'none') [none]  
  Enter where to store configs ('floppy', 'sda1', 'usb' or 'none') [sda1]:  
  Enter where to store configs ('floppy', 'sdU1', 'usb' or 'none') [sdU1]:  
  Enter apk cache directory (or '?' or 'none') [/media/sda1/cache]:
  Enter apk cache directory (or '?' or 'none') [/media/sdU1/cache]:


After the installer finished you can see how many created/modified files are detected and will be added to the backup:
After the installer finished you can see how many created/modified files are detected and will be added to the backup:
Line 55: Line 125:
  59
  59
  # lbu commit
  # lbu commit
  # ls -l /media/sda1/*apkovl.tar.gz
  # ls -l /media/sdU1/*apkovl.tar.gz
  -rwxr-xr-x    1 root    root          9591 Oct 19 15:23 /media/sda1/foo.apkovl.tar.gz
  -rwxr-xr-x    1 root    root          9591 Oct 19 15:23 /media/sdU1/foo.apkovl.tar.gz


Now all the customization are saved into the ''foo.apkovl.tar.gz'' compressed tarball on the USB stick itself.
Now all the customization are saved into the ''foo.apkovl.tar.gz'' compressed tarball on the USB stick itself.


== Troubleshooting ==
= Troubleshooting =


=== Slow USB Devices ===
=== Slow USB Devices ===
Line 66: Line 136:
  append initrd=/boot/grsec.gz alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet '''waitusb=3'''
  append initrd=/boot/grsec.gz alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet '''waitusb=3'''


== See Also ==
 
{{:Include:Installing_Alpine_see_also}}
=== CF card readers ===
 
Some CF card readers have problems with the faster CF cards on the market. If you experience problems booting the CF card even after checking BIOS settings, you may need to use an older card.
 
Also, many CF card readers don't support DMA correctly, so you may need to add ''nodma'' to the ''append'' line of the syslinux.cfg file.
 
 
 


[[Category:Installation]]
[[Category:Installation]]

Revision as of 23:42, 26 January 2022

This page is about creating directly customizable boot devices. If you are looking for instructions on creating (flashing) read-only (iso9660 "CD" filesystem) images onto installation media, see the Installation page instead.

A directly customizable Alpine Linux boot medium is basically an Alpine system in diskless or data disk-mode installed to (and booting from) a device with a writable filesystem. It allows to also upgrade the kernel with its modules and firmware that is used to boot the system with the update-kernel script.

The more general local customizations, the configs (.apkovl) and the package cache, may of course also be stored on the same device, as long as the hardware is not being set to be write-locked by a hardware switch.


Requirements

  • An Alpine Linux CD-ROM or an .iso file containing the desired Alpine release (Download).
  • A device like an USB drive (flash, external HD, card reader, etc.) or a CF "CompactFlash", or SDcard.

Using setup-bootable

This is now the preferable method to create a directly customizable bootable device.

It consists an Installation of a diskless or data mode system with configs and package cache on the target device, and using the setup-bootable script to make the device bootable.

Manually copying Alpine files

If you can't/won't use setup-bootable, you can manually create a customizable (writable) USB boot device instead.

Copying ISO/tarball contents to a USB stick

This method is written for copying files from an Alpine ISO file but also works for Alpine tarballs (.tar.gz files) with a one line tweak (see below).

  1. Install some prerequisites. (If you're not currently using Alpine Linux then you probably have these installed already, otherwise you'll have to figure out how to install them.)

    apk add dosfstools
    apk add syslinux

  2. Set the environment variable 'mydev' to the device file name of the USB stick that Alpine Linux is to be installed to:
    Warning: BE SURE TO GET THIS RIGHT OR ELSE YOU COULD OVERWRITE THE WRONG DISK!

    mydev=/dev/sdU

  3. Make sure that the target drive's existing partitions, if any, are not mounted:

    umount -q $mydev?

  4. Copy and paste the following as a single command to wipe the target drive, create an MBR partition table, and create a single FAT32 partition (you can ignore any "Partition #1 contains a vfat signature." warning message):

    fdisk -w always $mydev <<EOF o n p 1 2048 -0 t 0c a w EOF

  5. Format the new FAT32 partition with a FAT32 filesystem:

    mkdosfs -F32 ${mydev}1

  6. Copy the syslinix executable boot code into the bootstrap code area of the MBR boot sector (if you're not currently using Alpine Linux you may need to adjust the path to syslinux's mbr.bin file):

    dd bs=440 count=1 conv=notrunc if=/usr/share/syslinux/mbr.bin of=$mydev

  7. Install the syslinux bootloader files onto the FAT32 filesystem (ignore the "Hidden (2048) does not match sectors (62)" messages - modern systems use the partition table):

    syslinux ${mydev}1

  8. Copy the Alpine files to the FAT32 filesystem (to copy the contents of an Alpine .tar.gz tarball instead of copying /media/cdrom, set $alpinetarball to the path to the tarball and replace the 'cp' line with: tar -p -s --atime-preserve --same-owner --one-top-level=/media/$mydevname -zxvf "$alpinetarball"):

    mydevname=$(basename $mydev)1 mkdir -p /media/$mydevname mount -t vfat ${mydev}1 /media/$mydevname cp -aT /media/cdrom /media/$mydevname # -T to copy hidden files umount /media/$mydevname

  9. (Optional) Remove any .apkovl overlay files that were transferred as part of the copy process. Do this if you want an unmodified, vanilla install.

    mount -t vfat ${mydev}1 /media/$mydevname rm /media/$mydevname/*.apkovl.tar.gz umount /media/$mydevname


Troubleshooting

Wrong Device Name

If you cannot boot from the boot device and you see something like:

Mounting boot media failed.
initramfs emergency recovery shell launched. Type 'exit' to continue boot

then it is likely that the device name in syslinux.cfg is wrong. You should replace the device name in this line:

append initrd=/boot/grsec.gz alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet

with the proper device name.

  • For boot from USB, the device name should be 'usbdisk' (as shown above)
  • For other options, you can run cat /proc/partitions to see the available disks (i.e. 'sda' or 'sdb')

Non-FAT32 Filesystems

Diskless and data mode booting

When the boot device is formatted with a filesystem other than those supported by default, the necessary initfs features need to be added to the modloop using update-kernel. See: Alpine_Linux_package_management#Upgrading_.22diskless.22_and_.22data.22_disk_mode_installs

Sys mode booting

Mount the boot device and edit the syslinux.cfg file.

Then locate the "append" line, and change the alpine_dev= setting to match the used filesystem and add the filesystem's kernel module to the modules= list.

For example, change

append [...] alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet

to

append [...] alpine_dev=usbdisk:ext4 modules=loop,cramfs,sd-mod,usb-storage,ext4 quiet

in the case of an ext4 formatted partition. (Or correspondingly for other filesystems, if they are supported by syslinux and the Alpine Linux kernel.)

Finishing installation

After one has booted the previously created Alpine Linux bootable USB medium, one has to prepare USB stick to hold local customizations and run setup-alpine to finish the installation.

First let's find out where is our just booted USB media mounted, the location could vary.

# mount | grep /media
/dev/sdU1 on /media/sdU1 type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro)

Create local directory on USB media to hold local APK cache (see APK Local Cache for details).

# mount -o remount,rw /media/sdU1
# mkdir /media/sdU1/cache
# setup-apkcache /media/sdU1/cache
# ls -l /etc/apk/cache
lrwxrwxrwx    1 root     root            17 Oct 19 13:16 /etc/apk/cache -> /media/sdU1/cache

Now run setup-alpine and proceed until a question about local disk selection - in diskless mode we won't use any disk (ie. our bootable media files is basically untouched) and we are going to use sdU1 to hold our system customization.

# setup-alpine
...
Which disk(s) would you like to use? (or '?' for help or 'none') [none] 
Enter where to store configs ('floppy', 'sdU1', 'usb' or 'none') [sdU1]: 
Enter apk cache directory (or '?' or 'none') [/media/sdU1/cache]:

After the installer finished you can see how many created/modified files are detected and will be added to the backup:

# lbu status
# lbu status | wc -l
59
# lbu commit
# ls -l /media/sdU1/*apkovl.tar.gz
-rwxr-xr-x    1 root     root          9591 Oct 19 15:23 /media/sdU1/foo.apkovl.tar.gz

Now all the customization are saved into the foo.apkovl.tar.gz compressed tarball on the USB stick itself.

Troubleshooting

Slow USB Devices

Specifying the 'waitusb=X' option at the end of the syslinux.cfg line might help with certain USB devices that take a bit longer to register. X stands for the amount of seconds kernel will wait before looking for the installation media.

append initrd=/boot/grsec.gz alpine_dev=usbdisk:vfat modules=loop,cramfs,sd-mod,usb-storage quiet waitusb=3


CF card readers

Some CF card readers have problems with the faster CF cards on the market. If you experience problems booting the CF card even after checking BIOS settings, you may need to use an older card.

Also, many CF card readers don't support DMA correctly, so you may need to add nodma to the append line of the syslinux.cfg file.