I have Debian on my Samsung laptop and want to reinstall (in order to get the names of the wifi drivers and to change su). My laptop will no longer boot from USB like it did with Windows.
I've reformatted the USB drive to make sure it's FAT32 and then reinstalled the iso file with unetbootin. I have also gone into BIOS and changed the boot order, putting all the USB options before the hard drive. No change.
There's an option for a command line at GRUB but I'm too new to Linux to know what to do with it. Can I get some guidance on booting the USB from the command line?
Some webpage said to put in,
root (hd1,0)
but that returned an error message, "root command not recognized".
Scheduled Maintenance: We are aware of an issue with Google, AOL, and Yahoo services as email providers which are blocking new registrations. We are trying to fix the issue and we have several internal and external support tickets in process to resolve the issue. Please see: viewtopic.php?t=158230
Booting from USB at GRUB command line
- sunrat
- Administrator
- Posts: 6412
- Joined: 2006-08-29 09:12
- Location: Melbourne, Australia
- Has thanked: 116 times
- Been thanked: 461 times
Re: Booting from USB at GRUB command line
Unetbootin will probably not work for Debian. Read https://www.debian.org/CD/faq/#write-usb
“ computer users can be divided into 2 categories:
Those who have lost data
...and those who have not lost data YET ” Remember to BACKUP!
Those who have lost data
...and those who have not lost data YET ” Remember to BACKUP!
-
- Global Moderator
- Posts: 3049
- Joined: 2017-09-17 07:12
- Has thanked: 5 times
- Been thanked: 132 times
Re: Booting from USB at GRUB command line
Did you manage to display the runtime boot menu ?Persona wrote:I have also gone into BIOS and changed the boot order, putting all the USB options before the hard drive.
I guess this instruction is intended for the old GRUB legacy (GRUB 1). Debian uses GRUB 2 by default.Persona wrote:Some webpage said to put in
root (hd1,0)
The equivalent command for GRUB 2 would be
Code: Select all
set root=hd1,1
However, not every BIOS will expose a USB drive when booting from another drive. Check first with "ls" that the USB drive is exposed as (hd1) or so.
If the USB drive is not exposed, you must extract the files vmlinuz and initrd.gz from the installer filesystem (or download them from the installer section of a Debian mirror e.g. http://ftp.nl.debian.org/debian/dists/s ... ges/cdrom/) and store them on a drive which is exposed by the BIOS so that GRUB can read them. I suggest to put them in the /boot directory.
After setting the root location, you'll have to issue commands to load the files and boot :
Code: Select all
linux /boot/vmlinuz
initrd /boot/initrd.gz
boot
Re: Booting from USB at GRUB command line
@ sunrat
I followed the advice at the link and used Win 32 Disk Imager to create a bootable USB drive. It wasn't recognized during boot.
@ p.H
When I type
and then press the tab key, it lists the device (hd1) and the partition (hd1,msdos1) and for both of them it says "No known file system detected..."
Completing the command to set root=(hd1), followed by
returns error: unknown file system. I get the same response if I set the root to the hd1,msdos1 partition.
On another site, I saw the following advice:
This returned a black screen with a flashing cursor at the top left.
I followed the advice at the link and used Win 32 Disk Imager to create a bootable USB drive. It wasn't recognized during boot.
@ p.H
Not sure, I'm a bit hazy on what that is. If we're talking about something beyond a list showing the supposed order of devices checked at boot, then no.Did you manage to display the runtime boot menu ?
The command ls at the GRUB command line shows an (hd1) and (hd1,msdos1) which I assume is the USB drive as this laptop has only one hard drive.However, not every BIOS will expose a USB drive when booting from another drive. Check first with "ls" that the USB drive is exposed as (hd1) or so.
When I type
Code: Select all
set root=(hd
Completing the command to set root=(hd1), followed by
Code: Select all
linux /boot/vmlinux
On another site, I saw the following advice:
Code: Select all
set root=(hd1,1)
chainloader +1
boot
-
- Posts: 1454
- Joined: 2015-08-30 20:14
Re: Booting from USB at GRUB command line
1. Make sure DVD image is legit and fully downloaded. Incomplete image will be corrupted.
2. If on Windows, use Rufus to make a bootable image.
You can also use netinstall if you have spare smaller USB drives and good connection. Note that you will need either ethernet cable, or use non-free netinstall image for no nonsense wi-fi connection.
2. If on Windows, use Rufus to make a bootable image.
You can also use netinstall if you have spare smaller USB drives and good connection. Note that you will need either ethernet cable, or use non-free netinstall image for no nonsense wi-fi connection.
-
- Global Moderator
- Posts: 3049
- Joined: 2017-09-17 07:12
- Has thanked: 5 times
- Been thanked: 132 times
Re: Booting from USB at GRUB command line
I am talking about a menu which appears at boot time when pressing a given key, showing all available boot devices.Persona wrote:If we're talking about something beyond a list showing the supposed order of devices checked at boot,
If you installed the raw ISO image on the USB drive using cp, dd or win32diskimager, then the filesystem type is iso9660. Maybe you need to load the filesystem module first :Persona wrote:No known file system detected
Code: Select all
insmod iso9660
Code: Select all
insmod fat
Debian installer ISO images are "hybrid" and contain a bootable MBR, so the chainloader option may work, but you might need to swap hd0 and hd1 first.