Need help to understand why kdump is for 64 bit PPC only

Need help to understand why kdump is for 64 bit PPC only

[Frank Fan]

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Hello,

I am working on a freescale MPC8572 CPU board and use 32 bit Linux2.6.28.
When I enable 64 bit, it shows "kdump" in "kernel options". Otherwise,
"kdump" is disabled.
Can someone give me some hint why kdump is for 64 bit PPC only?

Thanks for the help,

Frank Fan
Alcatel-Lucent
Salt Lake City, UT, USA

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Re: Need help to understand why kdump is for 64 bit PPC only

[Kumar Gala]

On Dec 15, 2008, at 12:58 PM, Frank Fan wrote:

> Hello,
>
> I am working on a freescale MPC8572 CPU board and use 32 bit  
> Linux2.6.28.  When I enable 64 bit, it shows "kdump" in "kernel  
> options". Otherwise, "kdump" is disabled.
> Can someone give me some hint why kdump is for 64 bit PPC only?

Probably because no one has implemented or tested it on ppc32/8572.

- k

Re: Need help to understand why kdump is for 64 bit PPC only

[Michael Ellerman]

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On Mon, 2008-12-15 at 13:35 -0600, Kumar Gala wrote:
> On Dec 15, 2008, at 12:58 PM, Frank Fan wrote:
> 
> > Hello,
> >
> > I am working on a freescale MPC8572 CPU board and use 32 bit  
> > Linux2.6.28.  When I enable 64 bit, it shows "kdump" in "kernel  
> > options". Otherwise, "kdump" is disabled.
> > Can someone give me some hint why kdump is for 64 bit PPC only?
> 
> Probably because no one has implemented or tested it on ppc32/8572.

Pretty much, the 32-bit version of default_machine_kexec() is pretty
naïve, but you never know it might work.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

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Re: Need help to understand why kdump is for 64 bit PPC only

[Josh Boyer]

On Tue, 16 Dec 2008 07:33:04 +1100
Michael Ellerman <michael@ellerman.id.au> wrote:

> On Mon, 2008-12-15 at 13:35 -0600, Kumar Gala wrote:
> > On Dec 15, 2008, at 12:58 PM, Frank Fan wrote:
> >=20
> > > Hello,
> > >
> > > I am working on a freescale MPC8572 CPU board and use 32 bit =20
> > > Linux2.6.28.  When I enable 64 bit, it shows "kdump" in "kernel =20
> > > options". Otherwise, "kdump" is disabled.
> > > Can someone give me some hint why kdump is for 64 bit PPC only?
> >=20
> > Probably because no one has implemented or tested it on ppc32/8572.
>=20
> Pretty much, the 32-bit version of default_machine_kexec() is pretty
> na=C3=AFve, but you never know it might work.

You forgot the obligatory: "Or it could crash and cause your board to
catch on fire."

josh