Re: What is tools/firmware/rombios/32bit/... used for?

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 28/07/2014 22:14, Anthony Wright wrote:
> I'm trying to build xen on a pure 64 bit system, but the build is
> failing when it tries to build
> tools/firmware/rombios/32bit/tcgbios/tcgbios.c with the error:
>
> /usr/include/gnu/stubs.h:7:27: fatal error: gnu/stubs-32.h: No such file
> or directory
>
> From reading around the error, it's caused by a lack of a 32 bit libc
> which would make sense as I only have a 64 bit libc on the system at the
> moment. To reduce the size of the distro (see my earlier Perl dependency
> post), I'd prefer to avoid having to build a 32 bit libc. I therefore
> wondered what tcgbios does and what the impact of failing to build the
> 32 bit support for it would be?
>
> thanks,
>
> Anthony.

hvmloader is a 32bit binary.  It is the first bit of code executed in
any HVM domain and has the job of preparing certain architectural bits
for the BIOS, followed by dropping into 16bit mode to execute the
provided BIOS image.  Irrespective of the rest of your install, it does
have to be built as a 32bit ELF file, as 32bit is the start mode of HVM
domains.

There is no way of avoiding the need for a 32bit set of headers if you
want to build the base components Xen needs to function.

~Andrew