Re: [PATCH v5 4/5] normal/main: Search for specific config files for netboot

[Daniel Kiper]

On Fri, Dec 13, 2019 at 03:28:37PM +0100, Javier Martinez Canillas wrote:
> On 11/29/19 4:46 PM, Daniel Kiper wrote:
> > On Wed, Oct 30, 2019 at 06:02:35PM +0100, Javier Martinez Canillas wrote:
> >> On 10/30/19 2:45 PM, Vladimir 'phcoder' Serbinenko wrote:
> >>> We had a discussion with Daniel and agreed on following:
> >>> 1) we accept the feature
> >>
> >> Great, thanks.
> >>
> >>> 2) we want to have an option to specify grub config file. And if this
> >>> option is present, the scanning would be disabled
> >>
> >> Sure, you mentioned that this should be a DHCP option. Which option were
> >> you thinking that could be used for this?
> >
> > We took closer look at DHCP RFC and it seems to us that it is more
> > complicated than we expected. So, let's do this differently. Please add
>
> Yes, I also took a closer look at the RFC and didn't see how what you
> proposed could be done.

It can be done using Vendor Class Identifier (60) and Vendor Specific
Information (43) options. Though it will complicate the GRUB code
needlessly at this point. So, it can be done if there are real users
for it and they are able properly define exchange between the DHCP
server and client.

> > a variable which can be used to disable this feature. However, it should
> > be noted in the GRUB doc that this variable has to be set in early
> > config file.
> >
>
> I don't know if that could work, since this logic is to fetch the config
> file where this variable could be set (or a load_env command invoked to
> load these from an env file).

"man grub-mkimage" and look for "early config"...

> Another option is to have this feature under a configure flag that will
> be disabled by default. Then distros that want the feature can enable it.

If we want to go that way I prefer runtime option for 
grub-mkimage/grub-mkstandalone
instead of build time configure option.

Daniel