[PATCH] bootstd: Allow PXE boot to be disabled

[Tony Dinh]

Hi Tom & Simon,

On Fri, Oct 10, 2025 at 7:28 AM Tom Rini <trini at konsulko.com> wrote:
>
> On Thu, Oct 09, 2025 at 10:29:17PM -0700, Tony Dinh wrote:
>
> > Make it possible to disable CMD_PXE.
> > Remove unnecessary PXE_UTILS selection in BOOTMETH_EXTLINUX config.
> > In extlinux_boot(), invoke pxe utils only when
> > CONFIG_BOOTMETH_EXTLINUX_PXE is enabled.
> >
> > This patch results in about 9K reduction in image size when
> > PXE boot is disabled.
> >
> > Signed-off-by: Tony Dinh <mibodhi at gmail.com>
> > ---
> >
> >  boot/Kconfig             |  3 +--
> >  boot/bootmeth_extlinux.c | 18 ++++++++++--------
> >  2 files changed, 11 insertions(+), 10 deletions(-)
>
> Is some part of the symbol logic here wrong? A challenge is that "PXE"
> is also where the logic to parse extlinux.conf style files came from,
> and I thought we had split those two out. And then there's this:
>
> >
> > diff --git a/boot/Kconfig b/boot/Kconfig
> > index 2993cd7f9ba..403ce4c3d46 100644
> > --- a/boot/Kconfig
> > +++ b/boot/Kconfig
> > @@ -421,10 +421,10 @@ config BOOT_DEFAULTS_CMDS
> >       select CMD_PART if PARTITIONS
> >       select CMD_DHCP if CMD_NET
> >       select CMD_PING if CMD_NET
> > -     select CMD_PXE if CMD_NET
> >       select CMD_BOOTI if ARM64
> >       select CMD_BOOTZ if ARM && !ARM64
> >       imply CMD_MII if NET
> > +     imply CMD_PXE if CMD_NET
>
> This is one of the things where defaults isn't supposed to be so easy to
> get out of. How many platforms are you wanting to then disable CMD_PXE
> on to save space?

I'm simply trying to compile out PXE for a board that I'm working on!
The only thing I need is booting with scripts on a block device. And
it looks like we have to include everything in bootstd to use it. It
seems wrong to make the image a lot larger than needed for boards that
never use a specific feature.

I would agree about  "defaults isn't supposed to be so easy to get out
of". But in this case (and similarly in other CMD_x), CMD_PXE brings
in all dependencies for PXE including pxe_utils.

All the best,
Tony

>
> --
> Tom