Making a UEFI capable debian USB net-install
Just completed an install of debian on a Lenovo T480 running windows, for dual boot. The install was made more complex by the fact that the T480 doesn't have a CD, and that the laptop booted win10 in UEFI with secure boot. I was very surprised by the differing consensus of how to generate a UEFI bootable net-install. A simple dd of the image to the usb stick did NOT result in a UEFI bootable image. What did work, was formatting the usb stick vfat, and extracting the install iso onto it. I found this to be a clumsy workaround. Does anybody have a better method? Also, the literature was rife with warnings of Window's tendency to blow away the the linux bootloader (although some claims were made that this is less likely under UEFI). Does anyone have any experience with this, and what what is a likely recovery procedure for it? -- Michael Galea
On Fri, Jul 05, 2019 at 07:17:22PM -0400, Michael Galea via talk wrote:
Just completed an install of debian on a Lenovo T480 running windows, for dual boot. The install was made more complex by the fact that the T480 doesn't have a CD, and that the laptop booted win10 in UEFI with secure boot.
I was very surprised by the differing consensus of how to generate a UEFI bootable net-install. A simple dd of the image to the usb stick did NOT result in a UEFI bootable image. What did work, was formatting the usb stick vfat, and extracting the install iso onto it.
I found this to be a clumsy workaround. Does anybody have a better method?
Also, the literature was rife with warnings of Window's tendency to blow away the the linux bootloader (although some claims were made that this is less likely under UEFI). Does anyone have any experience with this, and what what is a likely recovery procedure for it?
dd of the debian install image has always made a bootable USB key for me, both on legacy BIOS and UEFI systems. Of course that is dd to the disk, not a partition on the disk. I have not had windows 10 ever break my linux boot loader. I don't remember if windows 7 ever did it either because that is so long ago. Before that it was a common problem for sure. -- Len Sorensen
On 2019-07-08 11:17 a.m., Lennart Sorensen wrote:
On Fri, Jul 05, 2019 at 07:17:22PM -0400, Michael Galea via talk wrote:
Just completed an install of debian on a Lenovo T480 running windows, for dual boot. The install was made more complex by the fact that the T480 doesn't have a CD, and that the laptop booted win10 in UEFI with secure boot.
I was very surprised by the differing consensus of how to generate a UEFI bootable net-install. A simple dd of the image to the usb stick did NOT result in a UEFI bootable image. What did work, was formatting the usb stick vfat, and extracting the install iso onto it.
I found this to be a clumsy workaround. Does anybody have a better method?
Also, the literature was rife with warnings of Window's tendency to blow away the the linux bootloader (although some claims were made that this is less likely under UEFI). Does anyone have any experience with this, and what what is a likely recovery procedure for it?
dd of the debian install image has always made a bootable USB key for me, both on legacy BIOS and UEFI systems. Of course that is dd to the disk, not a partition on the disk.
I have not had windows 10 ever break my linux boot loader. I don't remember if windows 7 ever did it either because that is so long ago. Before that it was a common problem for sure.
Thanks, I tried a plain dd first, but the Lenevo bios refused to recognize it as UEFI capable. Oh well.. As an aside, I noticed last night that Buster now supports secure boot, so I am off to try that on the T480. -- Michael Galea
On Mon, Jul 08, 2019 at 06:38:35PM -0400, Michael Galea via talk wrote:
Thanks, I tried a plain dd first, but the Lenevo bios refused to recognize it as UEFI capable. Oh well..
I know some systems you have to select the correct boot entry to boot in UEFI mode. So the same USB device can appear twice, once in legacy bios mode (sometimes labeled CSM) and once in UEFI mode. Of course the USB device will be missing the second copy of the GPT which could cause a problem if someone didn't implement the BIOS to the spec. GPT should have a backup copy of the partition table at the end of the device, but you should never require it to be present to work. I haven't ever encountered a system that had a problem with this though. I also believe the location of the backup is in the GPT header, so the dd'd image should actually have the backup in the right location as per the header, but sometimes software developers think they are smarter than the spec and make incorrect assumptions. I have not tried the new installer for buster yet though, but I highly doubt it doesn't work since it has had a lot of testing by a lot of people.
As an aside, I noticed last night that Buster now supports secure boot, so I am off to try that on the T480.
I don't think I can be bothered to try secureboot. -- Len Sorensen
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Michael Galea