[meta-intel] [PATCH 04/31] intel-ucode: a new MACHINE_FEATURE for meta-intel BSPs

[Tom Zanussi]

On Fri, 2014-09-19 at 11:22 -0500, Kamble, Nitin A wrote:
> 
> On 9/19/14, 6:40 AM, "Zanussi, Tom" <tom.zanussi at intel.com> wrote:
> 
> >On Thu, 2014-09-18 at 17:35 -0700, nitin.a.kamble at intel.com wrote:
> >> From: Nitin A Kamble <nitin.a.kamble at intel.com>
> >> 
> >> The Intel microcode can be enabled or disabled for each of the BSP by
> >> using the MACHINE_FEATURES variable.
> >>  All the BSPs which can utilize the feature need a line like this
> >> in their machine configuration file.
> >> 
> >> MACHINE_FEATURES += "intel-ucode"
> >> 
> >
> >As a new user-visible feature, this should have documentation, and in
> >fact, users have already asked you for an explanation of what this
> >microcode thing is and why they need it, and more importantly, under
> >what conditions they might not want it or if there are any risks
> >involved.
> 
> What kind of documentation are you looking for here? As this is specific
> to meta-intel layer and BSPs, the generic BSP developer¹s manual is not
> the right place for this.
> Is there documentation of any other feature which can be looked at as an
> example?
> 

This could be new ground and we may need to create a home for things
like this.  In the past, we've mainly documented things in the
individual BSP READMEs, but with those going away in favor of the new
emphasis on layer-wide features, we'll need a place to document those
kinds of things.  We do have the top-level meta-intel README, but I'm
wondering if we need a different file like oe-core has README.hardware.

Tom


> Thanks,
> Nitin
> 
> >
> >Thanks,
> >
> >Tom
> >
> >> Signed-off-by: Nitin A Kamble <nitin.a.kamble at intel.com>
> >> ---
> >>  conf/machine/include/meta-intel.inc | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >> 
> >> diff --git a/conf/machine/include/meta-intel.inc
> >>b/conf/machine/include/meta-intel.inc
> >> index f43903e..b94e1dd 100644
> >> --- a/conf/machine/include/meta-intel.inc
> >> +++ b/conf/machine/include/meta-intel.inc
> >> @@ -22,8 +22,8 @@ XSERVER_X86_ASPEED_AST = "xf86-video-ast \
> >>             "
> >>  
> >>  # include the user space intel microcode loading support in the
> >>generated images.
> >> -MACHINE_ESSENTIAL_EXTRA_RDEPENDS_append = " intel-microcode
> >>iucode-tool"
> >> +MACHINE_ESSENTIAL_EXTRA_RDEPENDS_append =
> >>"${@bb.utils.contains('MACHINE_FEATURES', 'intel-ucode', '
> >>intel-microcode iucode-tool', '', d)}"
> >>  
> >> -# For the early boot time kernel microcode loading support,
> >> +# for the early boot time kernel microcode loading support,
> >>  # merge the microcode data in the final initrd image.
> >> -INITRD_prepend = "${DEPLOY_DIR_IMAGE}/microcode.cpio "
> >> +INITRD_prepend = "${@bb.utils.contains('MACHINE_FEATURES',
> >>'intel-ucode', '${DEPLOY_DIR_IMAGE}/microcode.cpio ', '', d)}"
> >
> >
>