Re: UEFI question

From	blind Pete <0123peter@gmail.com>
Newsgroups	alt.os.linux
Subject	Re: UEFI question
Date	2016-01-03 15:14 +1100
Organization	A noiseless patient Spider
Message-ID	<2qjmlc-edb.ln1@psd.motzarella.org> (permalink)
References	<n60hg5$h8a$1@dont-email.me> <n60j2j$2chn$1@saria.nerim.net> <n60khc$rip$1@dont-email.me> <jf0ilc-fk8.ln1@psd.motzarella.org> <n65q35$51q$1@dont-email.me>

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crankypuss wrote:

> blind Pete wrote:
> 
>> crankypuss wrote:
> 
>>> From the theoretical correctness of those statements, I tend to
>>> conclude that a legacy BIOS system will remain unaffected by the
>>> presence/absence of an ESP, it's just some other partition not to be
>>> concerned with. However, the ESP only appears in GPT tables (doesnt'
>>> it?), so there's a question of whether (all non-broken) legacy BIOS
>>> systems will boot from a GPT-formatted device (and I've heard
>>> anecdotal comments that lead me to believe they will, but I haven't
>>> yet validated that myself).
>> 
>> Legacy BIOS firmware or UEFI firmware in legacy mode?
>> 
>> It is possible to prepare a hybrid drive that looks like an MSDOS
>> partitioned drive to a legacy BIOS, but is usable as a GPT drive.
>> Such things are generally regarded as unreliable abominations.
> 
> Unreliable abominations aside, I'm going to take a step back here and
> describe what I'm trying to do, as simply as I can.
> 
> I have multiple linux root partitions on a single USB stick.  Some of
> these partitions contain only one kernel, others contain several, but
> they are all bootable linux installs, and they are all 32-bit builds.
> 
> Each such USB stick is used for backup/rescue/recovery.  I need to boot
> any of these on 3 different machines which have different firmware:
> 
> Acer AOA150: 32-bit processor, legacy BIOS.
> 
> Dell XPS13: 64-bit processor, UEFI Firmware, but will boot in legacy
> mode if the boot partition is physical (not logical) and its boot flag
> is set.
> 
> ASUS T150: 64-bit processor with 32-bit UEFI Firmware, will not even
> consider booting a non-UEFI device.

To the best of my knowledge the ASUS is broken, but I'm not 
authoritative on that.  

> I've been successfully handling the Acer/Dell cases with MSDOS partition
> table having one physical partition (boot flag set, grub2 installed)
> followed by an extended partition containing the other distros, one per
> partition.
> 
> I'm trying to understand how to add the ASUS case to the mix.  As far as
> I can tell the ASUS pushes me to using a GPT partition table, but beyond
> that the details get a little fuzzy.  I expect that by the time I get
> enough other things done that I can go back to the following two web
> pages, I'll be able to figure it out, cross fingers.  Any additional
> clarification would be helpful.
> 
> http://adam8157.info/blog/2015/04/hybrid-bootable-usb-stick-for-uefi-and-legacy-bios
> 
> https://www.debian-administration.org/users/dkg/weblog/112

Options are many; Fix the ASUS, buy a second USB stick, get devious.  
Remember that devious is dangerous.  If one OS hardware combination 
sees what looks like a genuine old style drive and changes it it 
might be no longer valid GPT drive.  Then the fun starts when 
something helpfully fixes the broken layout.  

Do you really need to have everything on one USB stick?  

-- 
blind Pete
Sig goes here...

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Thread

UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-30 05:11 -0700
  Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-12-30 13:35 +0100
    Re: UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-30 06:03 -0700
      Re: UEFI question Bit Twister <BitTwister@mouse-potato.com> - 2015-12-30 13:48 +0000
        Re: UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-30 14:10 -0700
          Re: UEFI question "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2015-12-30 16:26 -0500
            Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-12-31 10:21 +0100
              Re: UEFI question "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2015-12-31 08:50 -0500
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-12-31 16:19 +0100
                Re: UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-31 11:51 -0700
                Re: UEFI question Bit Twister <BitTwister@mouse-potato.com> - 2015-12-31 19:34 +0000
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-12-31 21:52 +0100
                Re: UEFI question "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2016-01-01 18:58 -0500
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-02 02:19 +0100
                Re: UEFI question blind Pete <0123peter@gmail.com> - 2016-01-03 16:30 +1100
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-03 11:12 +0100
                Re: UEFI question Eef Hartman <E.J.M.Hartman@gmail.com> - 2016-01-03 12:44 +0000
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-03 15:16 +0100
                Re: UEFI question blind Pete <0123peter@gmail.com> - 2016-01-03 23:12 +1100
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-03 15:22 +0100
                Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-02 01:53 -0700
                Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-02 12:08 +0100
                Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-02 10:47 -0700
            Re: UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-31 02:37 -0700
          Re: UEFI question Bit Twister <BitTwister@mouse-potato.com> - 2015-12-30 22:18 +0000
      Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-12-31 10:16 +0100
        Re: UEFI question crankypuss <invalid@invalid.invalid> - 2015-12-31 02:46 -0700
      Re: UEFI question blind Pete <0123peter@gmail.com> - 2016-01-01 21:20 +1100
        Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-01 05:08 -0700
          Re: UEFI question Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2016-01-01 21:51 +0100
            Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-01 15:17 -0700
              Re: UEFI question Bit Twister <BitTwister@mouse-potato.com> - 2016-01-01 23:06 +0000
                Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-02 02:16 -0700
                Re: UEFI question Bit Twister <BitTwister@mouse-potato.com> - 2016-01-02 10:04 +0000
                Re: UEFI question crankypuss <invalid@invalid.invalid> - 2016-01-02 03:39 -0700
                Re: UEFI question blind Pete <0123peter@gmail.com> - 2016-01-03 15:20 +1100
          Re: UEFI question blind Pete <0123peter@gmail.com> - 2016-01-03 15:14 +1100

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