[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: legacy-bios and uefi boot usb stick

From: Pascal Hambourg
Subject: Re: legacy-bios and uefi boot usb stick
Date: Sun, 14 May 2017 13:49:15 +0200
User-agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Thunderbird/45.8.0

Le 14/05/2017 à 13:12, John Frankish a écrit :
I've made a couple of dual legacy-bios/uefi boot usb sticks using grub-2.00.

Both of the usb sticks will uefi boot linux, but there appears to be a problem 
with legacy-bios boot of linux.

One of the usb sticks gives an "invalid partition table!" error

What displays the message ? GRUB or the BIOS firmware ? Do you get the GRUB 
rescue prompt ?
Some BIOS firmwares require that a primary partition has the boot flag.

It seems as though it is grub displaying the message.

In one case I get the "invalid partition table!" message and have to cycle the 

If the message was displayed by GRUB, I believe that you would at least get the GRUB rescue prompt.

It is true that the usb stick that boots has the efi partition set as bootable 
and the usb stick that fails to boot does not. Since both boot uefi I assumed 
this did not matter.

The boot flag is meaningless for UEFI boot, since boot sectors are not used.

Can fdisk be used to set the partition as bootable without data loss?


This looks like a very old version of fdisk. Cylinders are obsolete. Add -u to 
use sectors as unit instead.

It is a recent busybox version of fdisk.

Too bad is still uses obsolete metrics.

By my calculation and by gparted, there is about 1.27mb before the first 

Whatever. A GRUB BIOS core image takes less than 100 kB.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]