Re: [Xen-devel] [PATCH 4/4] x86: check for multiboot{1, 2} header presence

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Wed, Jun 19, 2019 at 12:11:43PM +0100, Andrew Cooper wrote:
> On 19/06/2019 12:02, Roger Pau Monne wrote:
> > After building the hypervisor binary. Note that the check is performed
> > by searching for the magic header value at the start of the binary.
> >
> > Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> > ---
> > Cc: Jan Beulich <jbeulich@xxxxxxxx>
> > Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> > Cc: Wei Liu <wl@xxxxxxx>
> > ---
> >  xen/arch/x86/Makefile | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
> > index 8a8d8f060f..9bb3bf6e6c 100644
> > --- a/xen/arch/x86/Makefile
> > +++ b/xen/arch/x86/Makefile
> > @@ -102,6 +102,9 @@ 
> > syms-warn-dup-$(CONFIG_SUPPRESS_DUPLICATE_SYMBOL_WARNINGS) :=
> >  $(TARGET): $(TARGET)-syms $(efi-y) boot/mkelf32
> >     ./boot/mkelf32 $(notes_phdrs) $(TARGET)-syms $(TARGET) 
> > $(XEN_IMG_OFFSET) \
> >                    `$(NM) $(TARGET)-syms | sed -ne 's/^\([^ ]*\) . 
> > __2M_rwdata_end$$/0x\1/p'`
> > +   # Check for multiboot{1,2} headers
> > +   od -t x4 -N 8192 $(TARGET) | grep 1badb002 > /dev/null
> > +   od -t x4 -N 32768 $(TARGET) | grep e85250d6 > /dev/null
> 
> Neat solution.  Is `grep -q` portable ?

It is, but grep -q closes the pipe on the first match, and then od
will return an error. Note sure whether there's a way to workaround
this issue, but I think the above is simple enough.

Thanks, Roger.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel