Re: [Qemu-devel] RFC: Add a new boot parameter to set delay time before seabios retry to boot

[Kevin O'Connor]

On Thu, Sep 06, 2012 at 08:36:24AM -0500, Anthony Liguori wrote:
> Amos Kong <address@hidden> writes:
> 
> > Hi all,
> >
> > Seabios supports automatically reboot after X second delay on failed 
> > boot [1],
> > I want to add a parameter for qemu, it's used put a boot parameter into 
> > romfile
> > for seabios to set the delay time.
> >
> > # qemu ... -boot order=n,menu=on,delay=5 ...
> >
> >
> > Comments & suggestions ? Thanks!
> 
> Why use a file and not just a key/value?

SeaBIOS already accepts a number of run-time config settings (such as
the reboot delay) via helper functions.  For example:

    u32 retrytime = romfile_loadint("etc/boot-fail-wait", 60*1000);

On QEMU, the above will pull the value from the fwcfg "file"
interface.  The "file" interface is used because SeaBIOS needs a
reliable way of obtaining a name, value size, and value.  It in no way
requires that there be a real file on the user's host machine.

-Kevin