Re: [PATCH] arch/x86/purgatory/Makefile: supress kexec-purgatory.c is up to date message

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, Oct 15, 2014 at 10:14:31AM +0800, WANG Chao wrote:
> On 10/14/14 at 05:52pm, Vivek Goyal wrote:
> > On Tue, Oct 14, 2014 at 12:46:58PM +0800, WANG Chao wrote:
> > > Supress this unnecessary message during kernel re-build
> > > (CONFIG_KEXEC_FILE=y):
> > > 
> > > make[1]: `arch/x86/purgatory/kexec-purgatory.c' is up to date.
> > > 
> > > Signed-off-by: WANG Chao <chaowang@redhat.com>
> > > ---
> > >  arch/x86/purgatory/Makefile | 1 +
> > >  1 file changed, 1 insertion(+)
> > > 
> > > diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
> > > index f52e033..2c835e3 100644
> > > --- a/arch/x86/purgatory/Makefile
> > > +++ b/arch/x86/purgatory/Makefile
> > > @@ -24,6 +24,7 @@ quiet_cmd_bin2c = BIN2C   $@
> > >  
> > >  $(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE
> > >  	$(call if_changed,bin2c)
> > > +	@:
> > 
> > Where can I find the description of "@:" and how does it work?
> 
> @ is used to suppress echo'ing. See:
> https://www.gnu.org/software/make/manual/html_node/Echoing.html
> 
> This is a trick to avoid "... is up to date" message". Check out commit
> a9358bc ("x86/build: Supress realmode.bin is up to date message").

Thanks for the explanations. Looks good to me.

Acked-by: Vivek Goyal <vgoyal@redhat.com>

Vivek