[UPDATE] New Boot-Loader Menu -- version 1.1

Tue May 3 21:23:14 UTC 2011

> -----Original Message-----
> From: John Baldwin [mailto:jhb at freebsd.org]
> Sent: Tuesday, May 03, 2011 2:01 PM
> To: Devin Teske
> Cc: freebsd-hackers at freebsd.org
> Subject: Re: [UPDATE] New Boot-Loader Menu -- version 1.1
> 
> On Tuesday, May 03, 2011 4:47:26 pm Devin Teske wrote:
> > > -----Original Message-----
> > > From: John Baldwin [mailto:jhb at freebsd.org]
> > > Sent: Tuesday, May 03, 2011 1:36 PM
> > > To: Devin Teske
> > > Cc: freebsd-hackers at freebsd.org
> > > Subject: Re: [UPDATE] New Boot-Loader Menu -- version 1.1
> > >
> > > On Tuesday, May 03, 2011 4:17:23 pm Devin Teske wrote:
> > > > > -----Original Message-----
> > > > > From: John Baldwin [mailto:jhb at freebsd.org]
> > > > > Sent: Tuesday, May 03, 2011 12:20 PM
> > > > > To: Devin Teske
> > > > > Cc: freebsd-hackers at freebsd.org
> > > > > Subject: Re: [UPDATE] New Boot-Loader Menu -- version 1.1
> > > > >
> > > > > On Tuesday, May 03, 2011 2:57:34 pm Devin Teske wrote:
> > > > > > > From: John Baldwin [mailto:jhb at freebsd.org]
> > > > > > > Sent: Tuesday, May 03, 2011 10:33 AM
> > > > > > > To: Devin Teske
> > > > > > > Cc: freebsd-hackers at freebsd.org; Olivier SMEDTS
> > > > > > > Subject: Re: [UPDATE] New Boot-Loader Menu -- version 1.1
> > > > > > >
> > > > > > > On Tuesday, May 03, 2011 12:31:14 pm Devin Teske wrote:
> > > > > > > >
> > > > > > > > On May 3, 2011, at 4:45 AM, John Baldwin wrote:
> > > > > > > >
> > > > > > > > > On Monday, May 02, 2011 8:48:31 pm Devin Teske wrote:
> > > > > > > > > > This version (1.1) works nearly identically to the
> > > > > > > > > > standard menu that ships with FreeBSD in that it
> > > > > > > > > > detects whether ACPI is enabled (truth be told, I
> > > > > > > > > > actually re-used the
> > > "acpienabled?"
> > > > > > > > > > function verbatim from /boot/beastie.4th by Scott Long
> > > > > > > > > > and Aleksander Fafula). The ACPI detection of my boot
> > > > > > > > > > loader (version
> > > > > > > > > > 1.1 or higher) should be identical to the detection of
> > > > > > > > > > the current boot-loader.
> > > > > > > >
> > > > > > > > Ugh. By "current", I meant 8.1-RELEASE (wasn't expecting
> > > > > > > > this stuff to be different in HEAD, which it is).
> > > > > > > >
> > > > > > > >
> > > > > > > > > Err, note that the acpienabled stuff is all different in
> > > > > > > > > HEAD than in 7/8 since acpi.ko no longer exists.  You
> > > > > > > > > should use the scheme from HEAD for handling ACPI
> > > > > > > > > present vs ACPI
> > > enabled/disabled.
> > > > > > > > >
> > > > > > > > > --
> > > > > > > > > John Baldwin
> > > > > > > >
> > > > > > > >
> > > > > > > > Ok, I see the new "acpipresent?" word (which replaces the
> > "arch-i386"
> > > > > > > > environment-test). Does this imply that we're going to
> > > > > > > > support ACPI on
> > > > > > > > non-i386 platforms (or already do)?
> > > > > > >
> > > > > > > amd64 and ia64 have always supported ACPI.  ia64 effectively
> > > > > > > requires
> > it.
> > > > > > > However, "hint.acpi.0.rsdp" is set by biosacpi.c in the i386
> > > > > > > loader bits, so other platforms will not set it, so the
> > > > > > > arch-i386 test is no longer
> > > > > > needed.
> > > > > >
> > > > > > If "hint.acpi.0.rsdp" is only set in the i386 pieces, wouldn't
> > > > > > that imply that the "acpipresent?" would return FALSE on IA64?
> > > > >
> > > > > Yes.  Right now the ACPI menu item is not displayed on ia64 and
> > > > > it never has been.  You can't actually boot IA64 with ACPI
> > > > > disabled, so there's no reason
> > > > for it
> > > > > to be in the menu.
> > > >
> > > > This raises a concern for my menu. Unlike the current menu, which
> > > > blanks-out menuitem #2 for IA64, I've chosen instead to insert an
> > > > inoperative menuitem with the text "ACPI Support: N/A".
> > >
> > > Hmm, I think you should just leave the menu item blank or not
> > > listed.  It
> > doesn't
> > > make sense to see a knob about ACPI support on a ppc box for
> > > example, and other platforms may grow platform-specific knobs in the
future
> as well.
> > >
> > > The current menu item is only blank as a hack to avoid renumbering the
> items.
> > > If you are already changing that around, then I'd just leave it out
> > > altogether unless ACPI is detected by the loader.
> > >
> >
> > I too avoid renumbering of the items.
> >
> > Having never actually booted a PPC or IA64 FreeBSD installation... is
> > it the case that the numbers displayed jump from 1 to 3 (no blank line
> > in-between 1 and 3, correct)?
> 
> Actually, I think PPC/IA64, etc. do not display the ACPI menu item at all and
they
> are numbered differently from i386 and amd64.  The ACPI menu item is only
> blank if ACPI is not present on i386 and amd64.
> 

You're absolutely right. I looked closer at the Forth in HEAD, and indeed you're
right.

"arch-i386" will always allocate a #2 to ACPI, but will only display it when
"hint.acpi.0.rsdp" is set whereas non-i386 architectures will assign #2 to the
next menuitem (Safe Mode).

I'll make a new version that mimics this behavior.

The overall goal is to:
a. Satisfy everbody on -hackers.
b. Announce final version on -questions and -announce for broader audience.
c. Try to satisfy critical concerns.
d. Approach -core about using it in base

Think I have a shot at (d)?
-- 
Devin

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