Re: And yet another UEFI/BIOS question: Work on both.
On Sun, 23 Sep 2018 10:58:54 -0400
Wayne Sallee <Wayne@WayneSallee.com> wrote:
> What do you recommend for setting up a system that will boot in
> either UEFI or BIOS mode, so if it is moved back and forth between
> UEFI and BIOS, it will boot every time?
I recommend you learn how to use Google or DuckDuckGo, etc. searches for
such basic queries. The following was the first result in the list of my
search. Total time spent: about 15 seconds.
Also, read up on "chainloading."
> Wayne Sallee
> On 09/21/2018 02:21 PM, Pascal Hambourg wrote:
> > Le 21/09/2018 à 08:34, steve a écrit :
> >> Le 20-09-2018, à 20:25:26 +0200, Pascal Hambourg a écrit :
> >>>>> You don't need to convert anything. UEFI can use DOS partition
> >>>>> tables.
> >>>> I know since that's what I'm currently doing.
> >>> Doing what ?
> >> Using msdos partition tables.
> > This is irrelevant because until now you were booting Debian in
> > legacy (BIOS) mode.
> >>> I am not talking about you doing anything. I am saying that
> >>> native UEFI boot (NOT legacy boot) can use a disk with a DOS
> >>> partition table, provided that it has an EFI system partition (Id
> >>> 0xef).
> >> Isn't it ef00?
> > No. ef00 is a gdisk specific mnemonic for the EFI system partition
> > type identifier in a GPT partition table. The actual GUID is
> > C12A7328-F81F-11D2-BA4B-00A0C93EC93B. (0x)ef is the partition type
> > identifier for an EFI system partition in a DOS partition table.
> >> Because what I finally did is install a fresh Debian on another
> >> device (using GPT) and the ACPI errors still were there.
> > In legacy mode (with a BIOS boot partition) or EFI mode (with an
> > EFI system partition) ?
> >> I used the opportunity of having another Debian to convert my sda
> >> disk to GPT tables, and change the BIOS setting to UEFI only (just
> >> for the sake of it). So all my disk have a GPT partition table
> >> except for the 3 ones for the RAID1 array. Not sure whether I can
> >> use the same manipulations to convert them to GPT also. But since
> >> they work fine, I might leave it as it is.
> > You can, but IMO it provides little value. GPT is useful in the
> > following cases :
> > - disk bigger that 2 TiB
> > - more that 4 partition without the extended/logical partition
> > kludge
> > - need to use PARTLABEL or PARTUUD (but RAID uses its own UUID)
> > - system disk for Windows in EFI mode
> > AFAICS none of these conditions apply to your RAID disks. However I
> > noticed that 2 out of the 3 RAID partition on each disk are logical
> > partitions. This is not necessary if there are only 3 partitions
> > per disk. So in order to get rid of the extended partition kludge,
> > you could either convert the logical partitions into primary
> > partitions or convert the partition table to GPT.