Re: [PATCH v3 0/5] hvmloader: Make ROM dependencies optional

[Keir Fraser <keir@xen.org>]

On 13/02/2012 12:56, "Ian Campbell" <Ian.Campbell@citrix.com> wrote:

> On Mon, 2012-02-13 at 12:51 +0000, Keir Fraser wrote:
>> On 11/02/2012 20:39, "Julian Pidancet" <julian.pidancet@gmail.com> wrote:
>> 
>>> This patch set mainly allows the user to build a seabios or rombios only
>>> version of hvmloader.
>>> In addition, when building a seabios only hvmloader, Option ROMs like
>>> vgabios and etherboot are no longer required, and therefore can be disabled
>>> from the build. Dependency on the bcc compiler can also be avoided the
>>> same way.
>> 
>> Applied, but I wonder why we still have the rombios support? Could we switch
>> over to seabios for 4.2 and get rid of the crufty old rombios code entirely?
> 
> We still use ROMBIOS with the traditional qemu-xen tree, I think we have
> to do that for compatibility with existing guests, for the same reason
> as we need to continue to support that traditional qemu-xen tree.

So guests that were installed with old qemu need to always boot with old
qemu? Because if the compatibility issue is only with saved guests, then we
don't need to keep old ROMBIOS around as it lives in saved-guest memory.

 -- Keir

> Post 4.2 we will be switching the default qemu to the upstream tree
> which uses SeaBIOS at which point the old-qemu+ROMBIOS combo becomes
> legacy/frozen etc. We don't support new-qemu+ROMBIOS nor old-qemu
> +SEABIOS.
> 
> Ian.
> 
>> 
>>  -- Keir
>> 
>>> v2: Separate patches for separate issues
>>>    Introduced config option to select which NIC to build ROM for
>>>    Fixed initial patch to build multiple etherboot ROMs in hvmloader
>>>    Option ROMs are keyed off wether or not rombios is enabled, rather than
>>> on an individual basis
>>>    Introduced config options to select support for rombios/seabios
>>> 
>>> v3: Fix mkhex script to take several file arguments on the command line
>>>     Reorganize hvmloader option ROM loading code to make it optionnal, and
>>> make bios->load_roms a callback that the BIOS support code has to implement
>>> if option ROM loading is desired.
>>>     Cosmetic change in tools/firmware/Makefile in the way seabios-dir is
>>> created.
>>> 
>>> Julian Pidancet (5):
>>>   hvmloader: Only compile 32bitbios_support.c when rombios is enabled
>>>   hvmloader: Allow the mkhex command to take several file arguments
>>>   firmware: Use mkhex from hvmloader directory for etherboot ROMs
>>>   hvmloader: Move option ROM loading into a separate optionnal file
>>>   firmware: Introduce CONFIG_ROMBIOS and CONFIG_SEABIOS options
>>> 
>>>  Config.mk                             |    5 +
>>>  tools/firmware/Makefile               |   18 ++--
>>>  tools/firmware/etherboot/Config       |    2 -
>>>  tools/firmware/etherboot/Makefile     |   13 +--
>>>  tools/firmware/hvmloader/Makefile     |   39 ++++---
>>>  tools/firmware/hvmloader/config.h     |    3 +-
>>>  tools/firmware/hvmloader/hvmloader.c  |  218
>>> +--------------------------------
>>>  tools/firmware/hvmloader/mkhex        |    3 +-
>>>  tools/firmware/hvmloader/option_rom.h |    7 +
>>>  tools/firmware/hvmloader/optionroms.c |  189 ++++++++++++++++++++++++++++
>>>  tools/firmware/hvmloader/rombios.c    |   63 +++++++++-
>>>  tools/firmware/hvmloader/seabios.c    |    5 +-
>>>  12 files changed, 302 insertions(+), 263 deletions(-)
>>>  create mode 100644 tools/firmware/hvmloader/optionroms.c
>> 
>> 
> 
>