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Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_bo
From: |
Fu Wei |
Subject: |
Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64 |
Date: |
Fri, 5 May 2017 18:41:17 +0800 |
Hi Julien,
On 5 May 2017 at 18:11, Julien Grall <address@hidden> wrote:
> Hi Andrew,
>
>
> On 05/05/17 10:01, Andrew Cooper wrote:
>>
>> On 05/05/17 09:57, Fu Wei wrote:
>>>
>>> Hi Stefano,
>>>
>>> On 4 May 2017 at 04:53, Stefano Stabellini <address@hidden>
>>> wrote:
>>>>
>>>> On Wed, 3 May 2017, Andrew Cooper wrote:
>>>>>
>>>>> On 02/05/17 08:06, address@hidden wrote:
>>>>>>
>>>>>> From: Fu Wei <address@hidden>
>>>>>>
>>>>>> This patch adds the support of xen_boot command for aarch64:
>>>>>> xen_hypervisor
>>>>>> xen_module
>>>>>> These two commands are only for aarch64, since it has its own protocol
>>>>>> and
>>>>>> commands to boot xen hypervisor and Dom0, but not multiboot.
>>>>>>
>>>>>> For other architectures, they are still using multiboot and module
>>>>>> commands.
>>>>>>
>>>>>> Signed-off-by: Fu Wei <address@hidden>
>>>>>
>>>>> Sorry if I am jumping in late and asking awkward questions, but what is
>>>>> special about Xen/aarch64 here? Why is it using a non-standard entry
>>>>> mechanism?
>>>>
>>>> Multiboot is not available on ARM. The boot protocol we have on ARM is
>>>> FDT based:
>>>>
>>>>
>>>> http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/arm/device-tree/booting.txt
>>>>
>>>> We often refer to it as "multiboot for arm" but in fact it is not
>>>> related to the x86 multiboot in any way.
>>>>
>>>> In Grub, the two protocols (multiboot and
>>>> docs/misc/arm/device-tree/booting.txt) are kept clearly distinct
>>>> (address@hidden). Hence, the need for this patch.
>>>
>>> Exactly, great thanks for your explanation! :-)
>>
>>
>> So it really is an entirely custom Xen booting protocol.
>
>
> Not really, Xen is using the Linux boot protocol. It does not allow to pass
> multiple modules. The multiboot used by x86 does not support ARM (see [1])
> and hence not supported by any bootloaders existing on ARM.
>
> The "multiboot for ARM" has been designed to be generic enough to be used by
> anyone (see [2]). And the original intention was to use "module" in
> grub.cfg. I don't know why we did this change.
yes, in the early patchset, I used multiboot and module command name,
But since the protocol we are using is not a real multiboot, so I
followed the suggestion (using xen_hypervisor and xen_module) to do
this change.
We don't want to confuse people. "module" is a command in the real
multiboot module.
if we don't use the real multiboot protocol, we avoid re-using its commands.
>
>>
>> It is unfortunate that this wasn't reviewed sensibly at the time (and
>> implemented in a project-neutral way), but it looks like the time to fix
>> that properly has long since passed.
>
>
> The bindings are project neutral. Only the commands in grub are not neutral,
> I cannot find why it is not.
>
> Cheers,
>
> [1] https://www.gnu.org/software/grub/manual/multiboot/multiboot.html
> [2]
> https://wiki.xen.org/wiki/Xen_ARM_with_Virtualization_Extensions/Multiboot
>
> --
> Julien Grall
--
Best regards,
Fu Wei
Software Engineer
Red Hat
- [PATCH v7 1/3] arm64: add "--nounzip" option support in xen_module command, (continued)
- [PATCH v7 1/3] arm64: add "--nounzip" option support in xen_module command, fu . wei, 2017/05/02
- [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, fu . wei, 2017/05/02
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Andrew Cooper, 2017/05/03
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Stefano Stabellini, 2017/05/04
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/05
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Andrew Cooper, 2017/05/05
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/05
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Julien Grall, 2017/05/05
- Re: [Xen-devel] [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64,
Fu Wei <=
Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Vladimir 'phcoder' Serbinenko, 2017/05/09
- Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/09
- Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/09
- Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Vladimir 'phcoder' Serbinenko, 2017/05/10
- Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/11
- Re: [PATCH v7 2/3] * util/grub.d/20_linux_xen.in: Add xen_boot command support for aarch64, Fu Wei, 2017/05/14
[PATCH v7 3/3] arm64: update the introduction of xen boot commands in docs/grub.texi, fu . wei, 2017/05/02
Re: [PATCH v7 0/3] arm64, xen: add xen_boot support into grup-mkconfig, Fu Wei, 2017/05/02
Re: [PATCH v7 0/3] arm64, xen: add xen_boot support into grup-mkconfig, Daniel Kiper, 2017/05/04