Re: Selecting the scheduler from boot menu

On Sat, 31 Jan 2026 12:44:07 -0800
Steve Kargl <kargls@comcast.net> wrote:

> On 1/31/26 12:35, Milan Obuch wrote:
> > On Sat, 31 Jan 2026 12:21:59 -0800
> > Steve Kargl <kargls@comcast.net> wrote:
> >   
> >> All,
> >>
> >> Is it possible modify the boot menu to select 4BSD or ULE during
> >> the boot process?  I've looked at the code in src/stand/forth, but
> >> unfortunately the language is foreign to me. Currently, one boots
> >> into FreeBSD, checks the kern.sched.name, and then may need to
> >> edit /boot/loader.conf to change to the other scheduler, and then
> >> reboot. 
> > 
> > Which version are you working on? I think something recent, maybe
> > 16-CURRENT. Loader was rewritten in lua some time ago.  
> 
> I'm looking at src/stand/forth, particular, menu-commands.4th.

Somehow, those old files are still present and installed, but no longer
used in boot process unless some non-standard build or configuration is
being used.

> If the boot menu is written in lua, it's still a foreign language to
> me. So, I would need some guidance on how to hack the menu up.
> 
> Yes, it is a convenience to have menu item. Dropping to the loader
> prompt is possible. Taking it to a logical extreme, let's retire the
> menu because everything can be set at the loader prompt.

I'll try to look there. I did not actually read files in /boot/lua
directory yet, but I have some lua experience and maybe I can come with
something if nobody acts quicker... but first I nedd to understand the
process.

Regards,
Milan