[Qemu-devel] Re: [SeaBIOS] [PATCH 0/4] qemu option loading

[Kevin O'Connor <kevin@koconnor.net>]

On Fri, Dec 18, 2009 at 04:52:08PM +0100, Gerd Hoffmann wrote:
> On 12/18/09 16:41, Anthony Liguori wrote:
>> I needed the following patch for this series to build:
>>
>> --- a/src/optionroms.c
>> +++ b/src/optionroms.c
>> @@ -13,6 +13,7 @@
>> +#include "paravirt.h" // qemu_cfg_*
>
>> --- a/src/paravirt.h
>> +++ b/src/paravirt.h
>> +u32 qemu_cfg_read_file(QemuCfgFile *entry, void *dst, u32 maxlen);
>
> Patch is very reasonable.
>
> /me wonders how it did build for me without warning about the missing  
> prototype ...

SeaBIOS tries to use -fwhole-program to optimize the build.
Unfortunately, that option appears to be a bit "bleeding edge", and
some gcc versions have a hard time with it.  So, SeaBIOS supports two
ways to build with -fwhole-program - one with "-combine", and one with
a textual inclusion of all files.  Unfortunately, some errors can be
masked in one type of build that are exposed in the other type.

The next major version of gcc should have support for "-flto".  Once
distros start shipping it, I think seabios should just support the new
lto mechanism and the standard non-whole-program build.  That should
simplify these build issues.

-Kevin