From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: Paolo Bonzini <pbonzini@redhat.com>,
David Gibson <david@gibson.dropbear.id.au>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>,
Thomas Huth <thuth@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
Cornelia Huck <conny@cornelia-huck.de>,
Stefano Garzarella <sgarzare@redhat.com>
Subject: Re: VW ELF loader
Date: Thu, 13 Feb 2020 12:43:12 +1100 [thread overview]
Message-ID: <9539866e-b3ca-cf29-5a05-164480f89075@ozlabs.ru> (raw)
In-Reply-To: <274037e5-9bd5-8507-4b4b-067a86225787@ozlabs.ru>
On 10/02/2020 11:31, Alexey Kardashevskiy wrote:
>
>
> On 07/02/2020 10:46, Paolo Bonzini wrote:
>> On 07/02/20 00:23, Alexey Kardashevskiy wrote:
>>>> Right, not unlike what you get with vof=on. :) I'm not against at all
>>>> that idea. I just don't understand what you refer to below as (2).
>>>> Does petitboot not have the problem because it kexecs the new kernel?
>>>
>>> Petitboot does not have this problem *if* it runs without SLOF, i.e.
>>> directly via -kernel and -initrd and uses OF CI (cut down version, about
>>> v3-v4 of my patchset, without block devices and grub lookup). In this
>>> case there is one device tree instance, fully synchronized with the
>>> machine state.
>>>
>>> If there is still SLOF and (2) is happening, then petitboot is screwed
>>> as any other kernel.
>>
>> Ok, so "minimal pseudo-OpenFirmware in QEMU" is doable and can get
>> everything right;
>
> I am not convinced that ditching drivers is not right; I am moving elf +
> mbr + gpt + grub loading to the guest though so 20 bytes blob becomes
> FDT-less firmmare, a few kbytes big.
Ok. So, I have made a small firmware which does OF CI, loads GRUB and
instantiates RTAS:
https://github.com/aik/of1275
Quite raw but gives the idea.
It does not contain drivers and still relies on QEMU to hook an OF path
to a backend. Is this a showstopper and without drivers it is no go? Thanks,
>> it's just work to set up PCI and do all that other
>> do_driver_stuff(), so you can either do it yourself or use
>> Linux+petitboot. Is this correct?
>
> Except using the "just" word, yes, correct ;)
>
>> Also, can a normal distro kernel run via -kernel/-initrd + the minimal
>> firmware in QEMU?
>
> Yes.
--
Alexey
next prev parent reply other threads:[~2020-02-13 1:43 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-01 13:39 VW ELF loader Alexey Kardashevskiy
2020-02-01 19:04 ` Paolo Bonzini
2020-02-02 11:51 ` Alexey Kardashevskiy
2020-02-02 17:38 ` Paolo Bonzini
2020-02-03 1:31 ` David Gibson
2020-02-03 1:28 ` David Gibson
2020-02-03 9:12 ` Paolo Bonzini
2020-02-03 9:50 ` David Gibson
2020-02-03 10:58 ` Alexey Kardashevskiy
2020-02-03 15:08 ` Paolo Bonzini
2020-02-03 22:36 ` Alexey Kardashevskiy
2020-02-03 22:56 ` Paolo Bonzini
2020-02-03 23:19 ` Alexey Kardashevskiy
2020-02-03 23:26 ` Paolo Bonzini
2020-02-04 6:16 ` Thomas Huth
2020-02-04 8:54 ` Cornelia Huck
2020-02-04 9:20 ` Restrictions of libnet (was: Re: VW ELF loader) Thomas Huth
2020-02-04 9:32 ` Thomas Huth
2020-02-04 9:33 ` Michal Suchánek
2020-02-05 5:30 ` David Gibson
2020-02-05 6:24 ` Thomas Huth
2020-02-10 7:55 ` David Gibson
2020-02-10 9:39 ` Michal Suchánek
2020-02-13 3:16 ` David Gibson
2020-02-04 23:18 ` VW ELF loader Alexey Kardashevskiy
2020-02-05 6:06 ` David Gibson
2020-02-05 9:28 ` Cornelia Huck
2020-02-06 4:47 ` David Gibson
2020-02-06 8:27 ` Paolo Bonzini
2020-02-06 23:17 ` Alexey Kardashevskiy
2020-02-06 23:45 ` Paolo Bonzini
2020-02-10 7:30 ` David Gibson
2020-02-10 10:37 ` Peter Maydell
2020-02-10 11:25 ` Paolo Bonzini
2020-02-14 3:23 ` David Gibson
2020-02-10 7:28 ` David Gibson
2020-02-10 11:26 ` Paolo Bonzini
2020-02-14 4:02 ` David Gibson
2020-02-05 5:58 ` David Gibson
2020-02-06 8:29 ` Paolo Bonzini
2020-02-06 23:23 ` Alexey Kardashevskiy
2020-02-06 23:46 ` Paolo Bonzini
2020-02-10 0:31 ` Alexey Kardashevskiy
2020-02-13 1:43 ` Alexey Kardashevskiy [this message]
2020-02-13 10:17 ` Paolo Bonzini
2020-02-14 0:01 ` Alexey Kardashevskiy
2020-02-14 2:30 ` David Gibson
2020-02-04 9:40 ` Christian Borntraeger
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