Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

[Jens Staal]

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From: Jens Staal <staal1978@gmail.com>
To: mischief@9.offblast.org
Subject: Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?
Date: Sat, 06 Dec 2014 09:16:36 +0100
Message-ID: <5372535.55CG3LncHs@krypton>

On Friday 05 December 2014 19:47:26 you wrote:
> jens,
> 
> are you booting on a 386 system or amd64? what is the hardware?

amd64. The laptop is a few years old, an ASUS K73BR ( an E-450 APU)

> 
> the 9boot prompt (the > where you give bootfile) is pretty simple, and you
> can only set variables. it cant do 'ls' or anything like that. if it cant
> find the bootfile it will take you back to the prompt iirc.

ah... ok. 

> as for gpt, there's no gpt support yet. i have program to do gpt in a
> similar fashion to disk/fdisk, but it's not quite polished up or integrated
> into 9front. it does work though :)
> 

Oh ok I was under the impression that it was included :) I switched to GPT 
after some mbr f*ck ups and when I switched to GPT I took the opportunity to 
also switch to UEFI and I am pretty happy with it (especially for booting 
multiple systems - currently dual boot Arch and Alpine linux). Also, I never 
really trusted extended partitions and the 4 primary partition limit of mbr is 
quite annoying :)


Will there be an announcement / heads up when the GPT stuff is included?

> is it possible you can drop into an EFI shell on your system to find the
> bootfile?
> 

it might be possible... on the other hand - perhaps it is just that simple 
that it tries to boot a non-existing amd64 system on the media... perhaps I 
should check that first.

> more information on EFI booting is in the 9boot(8) manual.

Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

[cinap_lenrek]

> A question about an "efi install" - I suppose that 9fat then will point to the 
> ESP partition? Will it understand or default to something like EFI/boot/Plan9/ 
> so that it can nicely co-exist with other OSes?

most likely yes, but it hasnt been tried yet :)

with DOS partition table, EFI just accesses 9FAT partition and looks for
\EFI\BOOT\BOOTX64.EFI and runs it. after that everything is the same as with
bios boot.

you can try copying /386/boot*.efi to EFI/boot/Plan9 in your ESP and see
if it gets started.

right now, the loader looks only for \PLAN9.INI in the boot partition
(whatever this is the ESP or 9FAT) and the bootfile= path is relative to
the boot partition thet EFI provides us.

--
cinap

Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

[Jens Staal]

On Saturday 06 December 2014 12:19:04 you wrote:
> we currently have no gpt support in fdisk. but mischief is working
> on it.

Thanks. Looking forward to it :)

> 
> from the description, it seems the efi loader has some problems.
> i assume the "some sort of shell" refers to the boot console (see
> 9boot(8)). in one case, it seemed to be unable to locate the kernel
> file from the boot media.
> 
> the bootloader; as a last action; prints "boot" before jumping to the
> kernel. if that just hangs, it means the kernel fails *before* it is
> able to attach to the GOP framebuffer.
> 
> possible causes (speculation):
> 
> - bad memory map (see *e820= boot parameter)
> - efi doesnt provide GOP (see *bootscreen= boot parameter)
> - maybe kernel image got corrupted (in memory?) due to wrong assumtptions
> - you might have tried to load an older kernel that has no *bootscreen=
> support - acpi?
> 
> what we can do to get some evidence:
> 
> hit any key on boot to get to the bootloader console (until you see the
> ">" prompt).

I did see that prompt in one of my combinations - I will have to check again. 
I think it was when I booted the CD in EFI mode.

> 
> then read what boot parameters where established by the loader:
> *e820=, *bootscreen=, and *acpi=
> you can use the "show" command to print the boot parameter environment.
> 

great! That will definitely help. I will get back to you when I have checked 
it.

> you can try serial console by specifying console=0 before booting the
> kernel. that way, we might see more early output of the kernel.
> if thats not an option, then all we can do commenting out code before
> bootscreeninit() in the kenrel to figure out where it fails.
> 

so I can write console=0 in plan9.ini on my bootable USB and this info will be 
available?

> the efi loader has pxe boot support. so you might be able todo the
> debugging this way without having to copy stuff to usb or burn cdroms.
> 
> keep in mind that the efi stuff is very fresh and has only been tested
> with thinkpads and qemu/vmware and vbox so far. it would be good to
> know what kind of machine this is.
> 

I noticed that the previous reply only got to mischief (now forwarded to list) 
with details about the machine.

In a way, if (in the future) the installer booted in BIOS mode still can do a 
GPT install, fighting with booting the install media in EFI mode is not that 
critical. That could then be dealt with afterwards as long as one can 
configure an "efi install" (no mbr, efi boot files installed in ESP 
partition...).

A question about an "efi install" - I suppose that 9fat then will point to the 
ESP partition? Will it understand or default to something like EFI/boot/Plan9/ 
so that it can nicely co-exist with other OSes?

> --
> cinap

Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

[cinap_lenrek]

we currently have no gpt support in fdisk. but mischief is working
on it.

from the description, it seems the efi loader has some problems.
i assume the "some sort of shell" refers to the boot console (see
9boot(8)). in one case, it seemed to be unable to locate the kernel
file from the boot media.

the bootloader; as a last action; prints "boot" before jumping to the
kernel. if that just hangs, it means the kernel fails *before* it is
able to attach to the GOP framebuffer.

possible causes (speculation):

- bad memory map (see *e820= boot parameter)
- efi doesnt provide GOP (see *bootscreen= boot parameter)
- maybe kernel image got corrupted (in memory?) due to wrong assumtptions
- you might have tried to load an older kernel that has no *bootscreen= support
- acpi?

what we can do to get some evidence:

hit any key on boot to get to the bootloader console (until you see the
">" prompt).

then read what boot parameters where established by the loader:
*e820=, *bootscreen=, and *acpi=
you can use the "show" command to print the boot parameter environment.

you can try serial console by specifying console=0 before booting the
kernel. that way, we might see more early output of the kernel.
if thats not an option, then all we can do commenting out code before
bootscreeninit() in the kenrel to figure out where it fails.

the efi loader has pxe boot support. so you might be able todo the
debugging this way without having to copy stuff to usb or burn cdroms.

keep in mind that the efi stuff is very fresh and has only been tested
with thinkpads and qemu/vmware and vbox so far. it would be good to
know what kind of machine this is.

--
cinap

Re: [9front] Booting EFI (or work-arounds to install 9front on GPT partition)?

[mischief]

jens,

are you booting on a 386 system or amd64? what is the hardware?

the 9boot prompt (the > where you give bootfile) is pretty simple, and you can only set variables. it cant do 'ls' or anything like that. if it cant find the bootfile it will take you back to the prompt iirc.

as for gpt, there's no gpt support yet. i have program to do gpt in a similar fashion to disk/fdisk, but it's not quite polished up or integrated into 9front. it does work though :)

is it possible you can drop into an EFI shell on your system to find the bootfile?

more information on EFI booting is in the 9boot(8) manual.