Re: [Qemu-devel] [Qemu-trivial] [PATCH] hw/i386/pc: reject to boot a wrong header magic kernel

[li guang]

在 2013-03-28四的 10:42 +0100，Stefan Hajnoczi写道：
> On Wed, Mar 27, 2013 at 02:10:31PM +0800, liguang wrote:
> > if head magic is missing or wrong unexpectedly, we'd
> > better to reject booting.
> > e.g.
> > I make a mistake to boot a vmlinuz for MIPS(which
> > I think it's for x86) like this:
> > qemu-system-x86_64 -kernel vmlinuz -initrd demord
> > then qemu report:
> > "qemu: linux kernel too old to load a ram disk"
> > that's misleading.
> > 
> > Signed-off-by: liguang <address@hidden>
> > ---
> >  hw/i386/pc.c |    4 +++-
> >  1 files changed, 3 insertions(+), 1 deletions(-)
> > 
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index b1e06fa..2b78dfc 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -683,8 +683,10 @@ static void load_linux(void *fw_cfg,
> >          if (load_multiboot(fw_cfg, f, kernel_filename, initrd_filename,
> >                             kernel_cmdline, kernel_size, header)) {
> >              return;
> > +        } else {
> > +            fprintf(stderr, "please assure specicified kernel is for 
> > x86!\n");
> > +            exit(1);
> 
> load_multiboot() can fail for other reasons so this error messing is
> misleading.  Giving QEMU a non-x86 kernel is just one scenario where
> this may fail.

according to my check of load_mutiboot function,
mostly it will return 0 if it's not multboot,
or 1 it's a multiboot, so print this message,
or can I just print "wrong kernel image!" ?

> 
> >          }
> > -        protocol = 0;
> >      }
> 
> Why did you drop protocol = 0?

I think we only want either normal or multi boot linux kernel,
I can't see meaning let other case go on.
so, here, if a normal kernel, OK, go on,
if multiboot, OK, go on,
others, NO, end up.
so, "protocol = 0" is meaningless here.