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* new OF: how can we use it?
@ 1999-05-27 15:38 Brad Midgley
  1999-05-27 19:39 ` Tom Rini
  0 siblings, 1 reply; 6+ messages in thread
From: Brad Midgley @ 1999-05-27 15:38 UTC (permalink / raw)
  To: linuxppc-dev


hi guys...

don't you think it would be a great help to the success of linux on
powermac if we could make the kind of elf binary that the new open
firmware loads? 

(it would also be nice to get it to include an initial ramdisk like paul
did with the coff binary) 

we could make bootable cd's for powermac
macos wouldn't be required any more
we could net-boot

what remains to be done? is the problem well understood/documented?

Brad
brad@pht.com | http://www.pht.com/~brad/



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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: new OF: how can we use it?
  1999-05-27 15:38 new OF: how can we use it? Brad Midgley
@ 1999-05-27 19:39 ` Tom Rini
  1999-05-27 23:28   ` Joel Klecker
  1999-05-28  0:28   ` David Edelsohn
  0 siblings, 2 replies; 6+ messages in thread
From: Tom Rini @ 1999-05-27 19:39 UTC (permalink / raw)
  To: Brad Midgley; +Cc: linuxppc-dev


On Thu, 27 May 1999, Brad Midgley wrote:

> don't you think it would be a great help to the success of linux on
> powermac if we could make the kind of elf binary that the new open
> firmware loads? 
[neat ideas nusked]
> what remains to be done? is the problem well understood/documented?

It might be the text segments at the start.  Basically we need to see how
darwin and netbsd/macppc are linked and what they do that we don't (or
that we do and don't need to).  This is of coruse only my understanding,
from a dozen emails w/ adrian sun (I have access to an iMac, he
wants/wanted to fix it).

---
Tom Rini (TR1265)
http://gate.crashing.org/~trini/


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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: new OF: how can we use it?
  1999-05-27 19:39 ` Tom Rini
@ 1999-05-27 23:28   ` Joel Klecker
  1999-05-27 23:33     ` Tom Rini
  1999-05-28  0:28   ` David Edelsohn
  1 sibling, 1 reply; 6+ messages in thread
From: Joel Klecker @ 1999-05-27 23:28 UTC (permalink / raw)
  To: linuxppc-dev


At 15:39 -0400 1999-05-27, Tom Rini wrote:
>On Thu, 27 May 1999, Brad Midgley wrote:
>> don't you think it would be a great help to the success of linux on
>> powermac if we could make the kind of elf binary that the new open
>> firmware loads?
>[neat ideas nusked]
>> what remains to be done? is the problem well understood/documented?
>
>It might be the text segments at the start.  Basically we need to see how
>darwin and netbsd/macppc are linked and what they do that we don't (or
>that we do and don't need to).  This is of coruse only my understanding,
>from a dozen emails w/ adrian sun (I have access to an iMac, he
>wants/wanted to fix it).

NetBSD/macppc kernels have the .note section that OF wants, 
Linux/powerpc kernels do not.

<ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/arch
/powerpc/powerpc/ofwmagic.S>

See also vger: linux/arch/ppc/chrpboot/{mknote.c,Makefile}.
-- 
Joel Klecker (aka Espy)                    Debian GNU/Linux Developer
<URL:mailto:jk@espy.org>                 <URL:mailto:espy@debian.org>
<URL:http://web.espy.org/>               <URL:http://www.debian.org/>

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: new OF: how can we use it?
  1999-05-27 23:28   ` Joel Klecker
@ 1999-05-27 23:33     ` Tom Rini
  1999-05-28  4:13       ` Troy Benjegerdes
  0 siblings, 1 reply; 6+ messages in thread
From: Tom Rini @ 1999-05-27 23:33 UTC (permalink / raw)
  To: Joel Klecker; +Cc: linuxppc-dev


On Thu, 27 May 1999, Joel Klecker wrote:

> At 15:39 -0400 1999-05-27, Tom Rini wrote:
> >On Thu, 27 May 1999, Brad Midgley wrote:
> >> don't you think it would be a great help to the success of linux on
> >> powermac if we could make the kind of elf binary that the new open
> >> firmware loads?
> >[neat ideas nusked]
> >> what remains to be done? is the problem well understood/documented?
> >
> >It might be the text segments at the start.  Basically we need to see how
> >darwin and netbsd/macppc are linked and what they do that we don't (or
> >that we do and don't need to).  This is of coruse only my understanding,
> >from a dozen emails w/ adrian sun (I have access to an iMac, he
> >wants/wanted to fix it).
> 
> NetBSD/macppc kernels have the .note section that OF wants, 
> Linux/powerpc kernels do not.
> 
> <ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/arch
> /powerpc/powerpc/ofwmagic.S>
> 
> See also vger: linux/arch/ppc/chrpboot/{mknote.c,Makefile}.

Hmm.  So has anybody tried booting a CHRP-specific 2.3.x kernel on a B&W
or iMac? :)

---
Tom Rini (TR1265)
http://gate.crashing.org/~trini/


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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: new OF: how can we use it?
  1999-05-27 19:39 ` Tom Rini
  1999-05-27 23:28   ` Joel Klecker
@ 1999-05-28  0:28   ` David Edelsohn
  1 sibling, 0 replies; 6+ messages in thread
From: David Edelsohn @ 1999-05-28  0:28 UTC (permalink / raw)
  To: Tom Rini; +Cc: Brad Midgley, linuxppc-dev


	I presume that vger's mknote does all of the following, but the
special details that CHRP requires are:

A standard ELF-format PowerPC program
	e_ident = \7FELF (first byte is hex 7F)
	e_ident[EI_CLASS] = 1
	e_type = 2
	e_machine = 20 (PowerPC)
	e_version = 1
	e_flags = 0

A "note" section which looks like:

	.section .note
	.align 4
	/* length of PowerPC string */
	.long 8
	/* length of note descriptor */
	.long 24
	/* code for PowerPC open firmware */
	.long 0x1275
	/* PowerPC string */
	.asciz "PowerPC"
	/* real-mode true=-1 false=0 */
	.long -1
	/* real base of OF (do not care / use defaults = -1) */
	.long -1
	/* real size of OF (do not care / use defaults = -1) */
	.long -1
	/* virtual base of OF (ignored in real-mode) */
	.long -1
	/* virtual size of OF (ignored in real-mode) */
	.long -1
	/* load base of program (example real mode 0x4000) */
	.long 0x4000

One needs to ensure that the loaded program base does not specify a
location which overwrites Open Firmware itself.

	The ELF header must contain a PT_NOTE segment table entry pointing
to the note section as well as PT_LOAD segment table entries pointing to
the actual program image.  The GNU linker for PowerPC probably does not
create a PT_NOTE segment in the loader header although it does include the
.note section in the image.

	If all is correct, OF transfers control to the image entry point
with the five OF parameters including the OF client services entry point
in r5 (third parameter).

David

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: new OF: how can we use it?
  1999-05-27 23:33     ` Tom Rini
@ 1999-05-28  4:13       ` Troy Benjegerdes
  0 siblings, 0 replies; 6+ messages in thread
From: Troy Benjegerdes @ 1999-05-28  4:13 UTC (permalink / raw)
  To: Tom Rini; +Cc: Joel Klecker, linuxppc-dev


On Thu, 27 May 1999, Tom Rini wrote:

> 
> On Thu, 27 May 1999, Joel Klecker wrote:
> 
> > At 15:39 -0400 1999-05-27, Tom Rini wrote:
> > >On Thu, 27 May 1999, Brad Midgley wrote:
> > >> don't you think it would be a great help to the success of linux on
> > >> powermac if we could make the kind of elf binary that the new open
> > >> firmware loads?
> > >[neat ideas nusked]
> > >> what remains to be done? is the problem well understood/documented?
> > >
> > >It might be the text segments at the start.  Basically we need to see how
> > >darwin and netbsd/macppc are linked and what they do that we don't (or
> > >that we do and don't need to).  This is of coruse only my understanding,
> > >from a dozen emails w/ adrian sun (I have access to an iMac, he
> > >wants/wanted to fix it).
> > 
> > NetBSD/macppc kernels have the .note section that OF wants, 
> > Linux/powerpc kernels do not.
> > 
> > <ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/arch
> > /powerpc/powerpc/ofwmagic.S>
> > 
> > See also vger: linux/arch/ppc/chrpboot/{mknote.c,Makefile}.
> 
> Hmm.  So has anybody tried booting a CHRP-specific 2.3.x kernel on a B&W
> or iMac? :)

Just tried using the latest vger 'chrpboot', which makes a zImage, from a
Pmac kernel, and got 'gunzipping...'
'Default Catch 0900'  (which is the decrementer exception)

FYI, netbooting uses standard bootp and tftp 8->


> 
> ---
> Tom Rini (TR1265)
> http://gate.crashing.org/~trini/
> 

> 

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|    Unix is user friendly... You just have to be friendly to it first.  |
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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~1999-05-28  4:13 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
1999-05-27 15:38 new OF: how can we use it? Brad Midgley
1999-05-27 19:39 ` Tom Rini
1999-05-27 23:28   ` Joel Klecker
1999-05-27 23:33     ` Tom Rini
1999-05-28  4:13       ` Troy Benjegerdes
1999-05-28  0:28   ` David Edelsohn

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