Re: [PATCH] Seabios - read e820 table from qemu_cfg

Kevin O'Connor
2010-01-30T03:35:13Z

On Fri, Jan 29, 2010 at 10:03:55AM +0100, Jes Sorensen wrote:
> On 01/28/10 05:39, Kevin O'Connor wrote:
> >The advantage being that it should be possible to write one set of
> >helper functions in both qemu and seabios that can then be used to
> >pass arbitrary content.
>
> The only issue here is that I designed the Seabios portion to not rely
> on the size of the struct, to avoid having to statically reserve it like
> in your example. Having the qemu_cfg_get_file() function return a
> pointer to a file descriptor and then have a qemu_cfg_read() helper that
> takes the descriptor as it's first argument would avoid this problem.

SeaBIOS already has a maximum size for the e820 map (32) - see
CONFIG_MAX_E820.

> >As a side note, it should probably do the e820 map check even for qemu
> >users (ie, not just kvm).
>
> Ah I didn't realize Seabios would try to use the fw_cfg interface if it
> wasn't running on top of QEMU. That would be good to do.

Your patch only used it for kvm. SeaBIOS will use fw_cfg on both qemu
and kvm.

-Kevin