SMP Bootup

[James Hendricks]

> All the code I've seen requires that you build either an ACPI table or
> an Intel MP 1.x table.

I'll assume you meant APIC (Advanced Programmable Interrupt Controller)
instead of ACPI. (Isn't that Advanced Computer Power Interface?)  Or is
ACPI something different? (too many acronyms)

Looks like I have to build both APIC and Intel MP tables; I am not too
excited about that.  I guess I'll just printk() everything and hardwire
everything in to start with. I don't even think I need to store the
information where the bios would; I just need to assign variables.  I have
no idea how we are going to do autodetection..

I am working with kernel 2.4.0-test1; the only file I believe I need to
edit is mpparse.c.  Does this sound right to everybody?

- James

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[fb-d] SMP Bootup

[Jeff Garzik]

James Hendricks wrote:
> > All the code I've seen requires that you build either an ACPI table or
> > an Intel MP 1.x table.
>
> I'll assume you meant APIC (Advanced Programmable Interrupt Controller)
> instead of ACPI. (Isn't that Advanced Computer Power Interface?)  Or is
> ACPI something different? (too many acronyms)
>
> Looks like I have to build both APIC and Intel MP tables; I am not too
> excited about that.  I guess I'll just printk() everything and hardwire
> everything in to start with. I don't even think I need to store the
> information where the bios would; I just need to assign variables.  I have
> no idea how we are going to do autodetection..

I meant ACPI.  :)  ACPI is mainly associated with power management right
now, but it is a lot more than just that.  ACPI tables are information
tables found on all new computers, built by BIOS as a completely
platform independent way of initializing CPUs, routing interrupts,
managing power, and other stuff.

Check out arch/ia64 and "grep -i acpi" in there.  You'll see where the
kernel boot code reads CPU and interrupt info from ACPI tables.

But for X86 that is not the path of least resistence -- you'll still
have to write or port ACPI infrastructure to X86.  To accomplish your
goal quickly it is probably best to simply create the tables expected by
mpparse.c...
> I am working with kernel 2.4.0-test1; the only file I believe I need to
> edit is mpparse.c.  Does this sound right to everybody?

Yes but where does mpparse get its info from?

I don't see any way around building a memory map in FreeBIOS for
anything more than simple configurations...

Jeff

[fb-d] SMP Bootup

[Maciej W. Rozycki]

On Sat, 10 Jun 2000, Jeff Garzik wrote:
> > I am working with kernel 2.4.0-test1; the only file I believe I need to
> > edit is mpparse.c.  Does this sound right to everybody?
>
> Yes but where does mpparse get its info from?

It usually gets a table from BIOS.  But it need not to.  See
construct_default_ISA_mptable() for how the so-called default MP
configurations are handled.

If you know details of a particular SMP board you may either build an MPS
compliant MP table or provide an alternate way of providing this
information together with a backend called from find_smp_config().  The
backend may reuse existing code like construct_default_ISA_mptable() does.