GRML2USB(8) | GRML2USB(8) |
NAME¶
grml2usb - install Grml ISO(s) on USB device for booting
SYNOPSIS¶
grml2usb [ options ] <ISO[s]> <device>
Important! The Grml team does not take responsibility for loss of any data!
INTRODUCTION¶
grml2usb installs Grml on a given partition of your USB device and makes it bootable. It provides multiboot ISO support, meaning you can specify several Grml ISOs on the command line at once and select the Grml flavour you would like to boot on the bootprompt then. Note that the first ISO specified on the grml2usb command line will become the default one (that’s the one that will boot when just pressing enter on the bootprompt or wait until the boot timeout matches).
Important
By default a compatible master boot record (MBR) is installed on the device (being for example /dev/sdX when executing grml2usb grml.iso /dev/sdX1) and syslinux is being used as default bootloader. Avoid installation of the default MBR using the --skip-mbr option or if you encounter any problems with the default MBR consider using --syslinux-mbr instead.
OPTIONS¶
ISO[s] should be the path to one or multiple grml-ISOs and/or the path to the currently running live-system (being /run/live/medium).
The device either might be a device name like /dev/sdX1 or a directory. When specifying a device name the device is mounted automatically. When specifying a directory grml2usb is assuming that you did set up a bootloader on your own (or don’t need one) and a bootloader won’t be installed automatically.
The following options are supported:
--bootoptions=...
--bootloader-only
--copy-only
--dry-run
--fat16
--force
--grub
--grub-mbr
--help
--mbr-menu
--quiet
--skip-addons
--remove-bootoption=...
--skip-bootflag
--skip-grub-config
--skip-mbr
--skip-syslinux-config
--skip-usb-check
--syslinux
--syslinux-mbr
-v, --version
--verbose
DEVELOPERS CORNER¶
Directory layout on USB device¶
boot/ ->
|-- addons/
| |-- allinone.img [grub - all in one image]
| |-- bsd4grml/ [MirBSD]
| |-- balder10.imz [FreeDOS]
| |-- memdisk [chainloading helper]
| |-- memtest [memtest86+]
|-- release/
| |-- grml/
| | |-- linux26 [Kernel]
| | |-- initrd.gz [initramfs]
| |-- grml64
| | |-- linux26 [Kernel]
| | |-- initrd.gz [initramfs]
| |-- grml-small
| | |-- linux26
| | |-- initrd.gz
| `-- grml64-small
| |-- linux26
| |-- initrd.gz
|-- grub/
| |-- grml.png [graphical bootsplash background image for grub2]
| |-- grub.cfg [configuration file for grub2]
| |-- menu.lst [configuration file for grub1]
| |-- splash.xpm.gz [splash screen for grub1]
`-- syslinux/
|-- grml.png [graphical bootsplash background image for syslinux]
|-- syslinux.cfg [main configuration file for syslinux]
`-- [....] [several further config files for syslinux]
grml/
|-- grml2usb.txt [not yet implemented]
|-- grml-cheatcodes.txt [list of bootoptions for Grml]
|-- grml-version.txt [file containing information about grml-version]
|-- LICENSE.txt [license information]
|-- md5sums [md5sums of original ISO]
|-- README.txt [informational text]
`-- web/ [browser related files]
|-- index.html
|-- style.css
`-- images/
|-- button.png
|-- favicon.png
|-- linux.jpg
`-- logo.png
live/
|-- grml/
| |-- filesystem.module [module specifying which squashfs should be used for grml]
| `-- grml.squashfs [squashfs file for grml]
|-- grml-small/
| |-- filesystem.module [module specifying which squashfs should be used for grml-small]
| `-- grml-small.squashfs [squashfs file for grml-small]
`-- ...
Grabbing the source¶
% git clone git://git.grml.org/grml2usb.git
Developers Debugging Hints¶
To play with grml2usb you can avoid using a real device via a loopback file setup, like:
# dd if=/dev/zero of=~/loopback bs=1M count=100 # adjust size to your needs # losetup /dev/loop1 ~/loopback
Then create according partitions either running for example:
# echo -en "n\np\n1\n\n\nt\n6\na\n1\n w\n" | fdisk /dev/loop1
or:
# parted /dev/loop1 -s "mkpart primary fat16 0 -1s mkfs 1 fat16"
Finally create a filesystem and execute grml2usb as needed:
# mkfs.vfat /dev/loop1 # grml2usb --bootloader-only /grml/isos/grml64-small_2018.12.iso /dev/loop1
Performance tracing¶
# blktrace -d /dev/sdX -o - | blkparse -i - # grml2usb grml64-full_2018.12.iso /dev/sdX1
TROUBLESHOOTING AND PITFALLS WHEN BOOTING¶
Here is a list of common error messages from BIOS/bootloader when trying to boot from USB.
Error message | ran out of input data. System halted |
Reason | Everything OK, except for the filesystem used on your USB device. So instead of fat16 you are using for example fat32. Fix: use the appropriate filesystem (fat16 for USB flash drive usually). The Bootsplash might be displayed, the kernel loads but you very soon get the error message. |
Error message | Invalid operating system |
Reason | the partition layout is not ok. Very probably there’s no primary partition (/dev/sdX{1..4}) or none has the flag bootable set. |
Error message | Boot error. |
Reason | Some BIOSses offer different modes for USB booting. The proper mode to boot a USB stick is USB-HDD. If that doesn’t work or is not supported by your system, you need to format your USB-Stick as USB-ZIP. To do this, syslinux contains an utility called mkdiskimage, which you can use to re-format your USB stick in USB-ZIP format running mkdiskimage -4 /dev/sdX 1 64 32. Please be aware that this procedure will erase all data on your stick. After executing mkdiskimage just continue installing as usual (grml2usb ... /dev/sdX4). Note that this is not going to work for any device larger than 8 GB, since mkdiskimage only supports 1024c 256h 63s. For a more detailed explanation, refer to /usr/share/doc/syslinux-common/usbkey.txt. |
Error message | No operating system found. |
Reason | you forgot to set the boot-flag on the partition. Or there really isn’t any operating system at all. :) |
Error message | kernel-panic: unable to mount root-fs... |
Reason | Kernel boots but fails to find the root filesystem. The root= argument in your kernel commandline is pointing to the wrong device. Adjust root=..., consider using root=UUID=.... |
Error message | Could not find kernel image: ... |
Reason | either a broken isolinux/syslinux version or a broken BIOS. Check out whether the vendor provides a BIOS update or if using bootloader grub instead of isolinux/syslinux fixes the problem. |
FREQUENTLY ASKED QUESTIONS (FAQ)¶
Where can I get grml2usb?¶
grml2usb is available as Debian package via the grml-testing Debian repository[1].
If you do not want to (or can’t) use the grml2usb Debian package you can either use the grml2usb git tree running:
git clone git://git.grml.org/grml2usb.git cd grml2usb make -C mbr sudo ./grml2usb ...
or download the provided http://grml.org/grml2usb/grml2usb.tgz (gpg signed md5 hash[2]). Download and extract the tarball and execute the provided script install.sh.
Note
It is NOT enough to have just the grml2usb script itself without the according files provided either via the Debian package, the git tree or the file grml2usb.tgz.
Why can’t I just dd the ISO to a USB device?¶
Well, you can. :) Starting with Grml 2009.10 the ISOs are dd-able straight out-of-the-box.
Important
Note that ANY existing data on your USB device will be destroyed when using the dd approach.
This allows you to dd the Grml ISO to your USB device (use for example rawwrite[3] if you’ve just a Windows system available) running:
% dd if=grml64-full_2018.12.iso of=/dev/sdX
where /dev/sdX is your USB device. Of course this doesn’t provide such a flexible system like with grml2usb (no multi-ISO setup, no additional default bootoptions,...) but it’s a nice way to get a working USB boot setup if you don’t have grml2usb available.
What’s the difference between grml2usb and just using dd?¶
grml2usb does not remove any data from your USB device and does not alter the partition table at all. grml2usb provides multi-ISO support, support for adding default bootoptions and selecting the bootloader (syslinux vs. grub) without having to manually touch the ISO at all.
What’s grml2iso?¶
grml2iso is a script which uses grml2usb to generate a multiboot ISO out of several Grml ISOs. See man grml2iso for further details.
Why is there a menu.lst and a grub.cfg inside /boot/grub/?¶
grml2usb supports grub version 1 (grub1) as well as grub version 2 (grub2). Whereas grub1 uses menu.lst the new version grub2 needs grub.cfg. Providing both files allows grml2usb to install grub on the target device no matter which grub version is available on the host where grml2usb is executed on.
grub-install fails with 'The file ../boot/grub/stage1 not read correctly ?!"¶
Check whether the partition has the right partition type. For example do NOT use FAT16 (partition type 6) when using a ext3 filesystem on the partition but instead use the correct partition type (83 - Linux) then.
grub-install complains about /sbin/grub-install and/or xfs_freeze?!¶
The following message:
You shouldn't call /sbin/grub-install. Please call /usr/sbin/grub-install instead! xfs_freeze: specified file ["/tmp/tmpqaBK6z/boot/grub"] is not on an XFS filesystem
This is "normal". grub-install sends those messages to stderr. To avoid hiding any possible real error messages grml2usb doesn’t ignore those messages.
grub-install complains about /boot/grub/device.map?!¶
The following message:
grub-probe: error: Cannot open `/boot/grub/device.map'
This is "normal" (at least with grub1). This isn’t a problem, because the device.map file will be generated on the target device anyway.
grub-install complains about a unary operator?!¶
The following message:
'/usr/sbin/grub-install: line 374: [: =: unary operator expected'
This is "normal". Just ignore it. (It usually doesn’t appear on the second invocation on the same device.)
grub-install fails with grub-probe: error: unknown filesystem?!¶
The following message:
grub-probe: error: unknown filesystem Auto-detection of a filesystem module failed. Please specify the module with the option `--modules' explicitly.
usually means that the device partition table says something else than the filesystem on the device. For example using FAT16 as filesystem type and using FAT32 as filesystem on the partition will not work. Either set filesystem type to FAT32 or format the partition using FAT16. It is essential that device partition table and filesystem use the same filesystem type.
grub-setup fails after Attempting to install GRUB to a partition instead of the MBR?!¶
The following message:
grub-setup: warn: Attempting to install GRUB to a partition instead of the MBR. This is a BAD idea. grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and its use is discouraged. grub-setup: error: Cannot read `/grub/core.img' correctly
appears when using grub2 versions older than 1.98 as those version introduced a regression which avoids that grub is being installed into a partition (PBR, Partition Boot Record) instead of MBR (Master Boot Record).
To work around this issue you can either 1) upgrade to grub versions >=1.98, 2) install grub into the MBR (Master Boot Record) using the --grub-mbr option of grml2usb or 3) switch to syslinux as bootmanager (just drop the --grub option).
I’m getting something like Error: /usr/share/grml2usb/grub/splash.xpm.gz can not be read"!?"¶
Looks like you’ve only the grml2usb script itself available. Please make sure you’ve the grml2usb Debian package installed. The most resent stable version is available via the grml-testing Debian repository[1]. If you do not have a Debian system please see section Where can I get grml2usb? in this FAQ.
Why do I have to use a FAT16/FAT32 filesystem?¶
Syslinux (currently) does not support any other filesystems besides FAT16/FAT32 (though that’s a sane default if you want to share your files with other (operating) systems). If you want to use a different filesystem (like ext2/3) use the bootloader grub instead using grml2usb’s --grub option.
Note
FAT32 is supported since syslinux version 3.0.
Addons → Hardware Detection Tool freezes¶
This usually means that the machine you ran grml2usb on had syslinux 3.x installed. The version of hdt (Hardware detection tool) shipping with Grml 2010.12 and newer requires syslinux 4.x.
I think I’ve got a really cool idea!¶
Great! Please check out the TODO file[4]. Feel free to report your wishes to the author. Patches highly appreciated.
I’ve problems with booting from USB.¶
Check out Troubleshooting and Pitfalls when booting.
I’ve found a bug!¶
Please report it to the author. Please provide usage examples and output of your grml2usb commandline (consider using the "--verbose" option).
USAGE EXAMPLES¶
# grml2usb /home/grml/grml64-full_2018.12.iso /dev/sdX1
Install specified ISO on device /dev/sdX1.
# grml2usb /home/grml/grml64-full_2018.12.iso /home/grml/grml32-full_2018.12.iso /dev/sdX1
Install specified ISOs on device /dev/sdX1 for multibooting ISOs.
# grml2usb /run/live/medium /dev/sdX1
Install currently running Grml live system on device /dev/sdX1.
# grml2usb /run/live/medium /home/grml/grml64-full_2018.12.iso /dev/sdX1
Install currently running Grml live system and the specified ISO on device /dev/sdX1 for multibooting.
# grml2usb --fat16 /home/grml/grml64-full_2018.12.iso /dev/sdX1
Install specified ISO on device /dev/sdX1 and format partition /dev/sdX1 with FAT16 filesystem.
# grml2usb --grub --grub-mbr /home/grml/grml64-full_2018.12.iso /dev/sdX1
Install specified ISO on device /dev/sdX1 and use grub as bootloader (instead of syslinux being the default) and install a master boot record (MBR) to the MBR of /dev/sdX.
# grml2usb --bootoptions="lang=de ssh=mysecret" grml64-full_2018.12.iso /dev/sdX1 # grml2usb --bootoptions="lang=de" --bootoptions="ssh=mysecret" grml64-full_2018.12.iso /dev/sdX1
Install specified ISO on device /dev/sdX1 and use "lang=de ssh=mysecret" as default bootoptions.
# grml2usb --remove-bootoption="vga=791" --remove-bootoption="nomce" grml64-full_2018.12.iso /dev/sdX1
Install specified ISO on device /dev/sdX1 remove vga=791 and nomce from existing bootoptions.
# grml2usb --bootoptions="persistent-path=%flavour_name" grml64-small_2018.12.iso grml32-small_2018.12.iso /dev/sdX1
Install specified ISOs on device /dev/sdx and add parameter persistent-path to every menu entry. %flavour_name will be expanded to the flavour of the specific iso, e.g. grml64 and grml.
ONLINE RESOURCES¶
Check out the grml2usb webpage[5] and the grml2usb git repository[6].
BUGS¶
Please report feedback, bugreports and wishes to the author.
AUTHOR¶
Michael Prokop <mika@grml.org[7]>
NOTES¶
- 1.
- the grml-testing Debian repository
- 2.
- gpg signed md5 hash
- 3.
- rawwrite
- 4.
- the TODO file
- 5.
- grml2usb webpage
- 6.
- grml2usb git repository
- 7.
- mika@grml.org
12/07/2024 |