Serial Console on XServe and yaboot???

Serial Console on XServe and yaboot???

[Bill Fink]

I'd like to use the serial port on the XServe as a serial console.
I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
set the OF input-device and output-device parameters to ttya, and
booted with the kernel argument "console=ttyS0,38400".

This actually works once the system starts booting.  My problem
is that I never get a chance to interact with yaboot and thus for
example can't select a different Linux kernel to boot.  Is there
any way to accomplish this, for example by some suitable modification
to the ofboot.b file in the boot partition?  Or is this just not
supported by the hardware?

Thanks in advance for any help or pointers, or even for informing
me that this is a hopeless quest.

						-Bill

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Re: Serial Console on XServe and yaboot???

[Benjamin Herrenschmidt]

On Wed, 2003-03-12 at 04:33, Bill Fink wrote:
> I'd like to use the serial port on the XServe as a serial console.
> I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
> set the OF input-device and output-device parameters to ttya, and
> booted with the kernel argument "console=ttyS0,38400".
>
> This actually works once the system starts booting.  My problem
> is that I never get a chance to interact with yaboot and thus for
> example can't select a different Linux kernel to boot.  Is there
> any way to accomplish this, for example by some suitable modification
> to the ofboot.b file in the boot partition?  Or is this just not
> supported by the hardware?
>
> Thanks in advance for any help or pointers, or even for informing
> me that this is a hopeless quest.

iirc, there is something weird with the OF params for the console
on the xserve. Try changing these:

intput-device    "scca"
output-device    "scca"
input-device-1   "scca"
output-device-1  "scca"

Ben.


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Re: Serial Console on XServe and yaboot???

[Brad Boyer]

On Wed, Mar 12, 2003 at 08:46:25AM +0100, Benjamin Herrenschmidt wrote:
> iirc, there is something weird with the OF params for the console
> on the xserve. Try changing these:
>
> intput-device    "scca"
> output-device    "scca"
> input-device-1   "scca"
> output-device-1  "scca"

It may be different on the xserve, but on my 7600, the names of the
serial ports in OF are 'ttya' and 'ttyb'.

	Brad Boyer
	flar@allandria.com


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Re: Serial Console on XServ and yaboot???

[Benjamin Herrenschmidt]

On Wed, 2003-03-12 at 09:51, Brad Boyer wrote:
> On Wed, Mar 12, 2003 at 08:46:25AM +0100, Benjamin Herrenschmidt wrote:
> > iirc, there is something weird with the OF params for the console
> > on the xserve. Try changing these:
> >
> > intput-device    "scca"
> > output-device    "scca"
> > input-device-1   "scca"
> > output-device-1  "scca"
>
> It may be different on the xserve, but on my 7600, the names of the
> serial ports in OF are 'ttya' and 'ttyb'.

Those are the alias names I found in an xserve device-tree dump I
keep around here. Looks like Apple changed them since the 7600...

Actually, "scca" and "sccb" are also the alias names on my tipb,
so I beleive this is a change on all newworlds or maybe all
core99's

Ben.


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Re: Serial Console on XServe and yaboot???

[Bill Fink]

Hi Ben,

On 12 Mar 2003, Benjamin Herrenschmidt wrote:

> On Wed, 2003-03-12 at 04:33, Bill Fink wrote:
> > I'd like to use the serial port on the XServe as a serial console.
> > I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
> > set the OF input-device and output-device parameters to ttya, and
> > booted with the kernel argument "console=ttyS0,38400".
> >
> > This actually works once the system starts booting.  My problem
> > is that I never get a chance to interact with yaboot and thus for
> > example can't select a different Linux kernel to boot.  Is there
> > any way to accomplish this, for example by some suitable modification
> > to the ofboot.b file in the boot partition?  Or is this just not
> > supported by the hardware?
> >
> > Thanks in advance for any help or pointers, or even for informing
> > me that this is a hopeless quest.
>
> iirc, there is something weird with the OF params for the console
> on the xserve. Try changing these:
>
> intput-device    "scca"
> output-device    "scca"
> input-device-1   "scca"
> output-device-1  "scca"

Thanks for the idea, but unfortunately it had no effect, as I saw
no yaboot screens show up when I did a reboot.  Is it possible that
the initial OF uses a different baud rate than 38400 (although I
didn't even see any garbage show up)?

						-Bill

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Re: Serial Console on XServe and yaboot???

[Benjamin Herrenschmidt]

On Wed, 2003-03-12 at 14:19, Bill Fink wrote:
> Hi Ben,
>
> On 12 Mar 2003, Benjamin Herrenschmidt wrote:
>
> > On Wed, 2003-03-12 at 04:33, Bill Fink wrote:
> > > I'd like to use the serial port on the XServe as a serial console.
> > > I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
> > > set the OF input-device and output-device parameters to ttya, and
> > > booted with the kernel argument "console=ttyS0,38400".
> > >
> > > This actually works once the system starts booting.  My problem
> > > is that I never get a chance to interact with yaboot and thus for
> > > example can't select a different Linux kernel to boot.  Is there
> > > any way to accomplish this, for example by some suitable modification
> > > to the ofboot.b file in the boot partition?  Or is this just not
> > > supported by the hardware?
> > >
> > > Thanks in advance for any help or pointers, or even for informing
> > > me that this is a hopeless quest.
> >
> > iirc, there is something weird with the OF params for the console
> > on the xserve. Try changing these:
> >
> > intput-device    "scca"
> > output-device    "scca"
> > input-device-1   "scca"
> > output-device-1  "scca"
>
> Thanks for the idea, but unfortunately it had no effect, as I saw
> no yaboot screens show up when I did a reboot.  Is it possible that
> the initial OF uses a different baud rate than 38400 (although I
> didn't even see any garbage show up)?

Hrm... I did manage to get it last time I played with an xserve. I
don't remember the baudrate though (maybe 57600...)

Ben.


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Re: Serial Console on XServe and yaboot???

[Bill Fink]

On 12 Mar 2003, Benjamin Herrenschmidt wrote:

> On Wed, 2003-03-12 at 14:19, Bill Fink wrote:
> >
> > On 12 Mar 2003, Benjamin Herrenschmidt wrote:
> >
> > > iirc, there is something weird with the OF params for the console
> > > on the xserve. Try changing these:
> > >
> > > intput-device    "scca"
> > > output-device    "scca"
> > > input-device-1   "scca"
> > > output-device-1  "scca"
> >
> > Thanks for the idea, but unfortunately it had no effect, as I saw
> > no yaboot screens show up when I did a reboot.  Is it possible that
> > the initial OF uses a different baud rate than 38400 (although I
> > didn't even see any garbage show up)?
>
> Hrm... I did manage to get it last time I played with an xserve. I
> don't remember the baudrate though (maybe 57600...)

I determined it is indeed 57600.  Does anyone know of any OpenFirmware
parameter on the XServe to set the baud rate of the serial port?
Unfortunately my current console server maxes out at 38400.

						-Bill

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Re: Serial Console on XServe and yaboot???

[Ethan Benson]

On Tue, Mar 11, 2003 at 10:33:53PM -0500, Bill Fink wrote:
>
> I'd like to use the serial port on the XServe as a serial console.
> I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
> set the OF input-device and output-device parameters to ttya, and
> booted with the kernel argument "console=ttyS0,38400".
>
> This actually works once the system starts booting.  My problem
> is that I never get a chance to interact with yaboot and thus for

you will need to use a different first stage (magicboot) or none at
all (if OF will boot that way, some models refuse to autoboot
binaries without the CHRP bootinfos).  the default ofboot script
installed with yaboot forces the output to screen to work around
stupid hacks in apple OF to prevent `archaic peecee text' from
appearing on the screen.

> example can't select a different Linux kernel to boot.  Is there
> any way to accomplish this, for example by some suitable modification
> to the ofboot.b file in the boot partition?  Or is this just not

never modify the bootstrap partition, edit the magicboot= line in
/etc/yaboot.conf to point to an alternate script.  you can make a copy
of the /usr/lib/yaboot/ofboot file, then find and change the line:

" screen" output

to

" ttya" output

later im going to fix this so it won't have this problem.

--
Ethan Benson
http://www.alaska.net/~erbenson/

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Re: Serial Console on XServe and yaboot???

[Bill Fink]

Hi Ethan,

On Tue, 11 Mar 2003, Ethan Benson wrote:

> On Tue, Mar 11, 2003 at 10:33:53PM -0500, Bill Fink wrote:
> >
> > I'd like to use the serial port on the XServe as a serial console.
> > I enabled CONFIG_SERIAL_CONSOLE in a 2.4.20-0.7b (YDL 2.3) kernel,
> > set the OF input-device and output-device parameters to ttya, and
> > booted with the kernel argument "console=ttyS0,38400".
> >
> > This actually works once the system starts booting. My problem
> > is that I never get a chance to interact with yaboot and thus for
>
> you will need to use a different first stage (magicboot) or none at
> all (if OF will boot that way, some models refuse to autoboot
> binaries without the CHRP bootinfos). the default ofboot script
> installed with yaboot forces the output to screen to work around
> stupid hacks in apple OF to prevent `archaic peecee text' from
> appearing on the screen.
>
> > example can't select a different Linux kernel to boot. Is there
> > any way to accomplish this, for example by some suitable modification
> > to the ofboot.b file in the boot partition? Or is this just not
>
> never modify the bootstrap partition, edit the magicboot= line in
> /etc/yaboot.conf to point to an alternate script. you can make a copy
> of the /usr/lib/yaboot/ofboot file, then find and change the line:
>
> " screen" output
>
> to
>
> " ttya" output
>
> later im going to fix this so it won't have this problem.

Thanks a bunch for the info!  Using this method, with scca instead
of ttya, and a baud rate of 57600 (using a laptop), I was able to
verify this basically works.  The initial menu that asks you what
you want to boot (Linux, MacOS 9, MacOS X, etc) still goes to the
screen (at least it does if you have a screen attached) but the
yaboot menu where you select the Linux kernel to boot does show
up on the serial port of the XServe, and this is what I'm most
interested in.  Now if I can just figure out how to set the baud
rate of the serial console for OF to 38400 or less to make my
console server happy, I'd be in business.  If nothing else I can
use the laptop approach which is at least a lot easier than toting
a big monitor around.

						-Bill

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Re: Serial Console on XServe and yaboot???

[Ethan Benson]

On Thu, Mar 13, 2003 at 10:29:01PM -0500, Bill Fink wrote:
>
> Thanks a bunch for the info!  Using this method, with scca instead
> of ttya, and a baud rate of 57600 (using a laptop), I was able to
> verify this basically works.  The initial menu that asks you what
> you want to boot (Linux, MacOS 9, MacOS X, etc) still goes to the
> screen (at least it does if you have a screen attached) but the

yes this is because i had to write all my text directly to the
framebuffer, apple takes all kinds of special efforts to prevent
`archaic peecee text' from showing up on the screen...  this problem
should be fixed in yaboot 2.0

i don't consider it too serious right now since if your doing serial
console your probably not running any macos.

you could probably fix this easily enough for your setup by altering
the `.printf' definition in ofboot.

> yaboot menu where you select the Linux kernel to boot does show
> up on the serial port of the XServe, and this is what I'm most
> interested in.  Now if I can just figure out how to set the baud
> rate of the serial console for OF to 38400 or less to make my
> console server happy, I'd be in business.  If nothing else I can
> use the laptop approach which is at least a lot easier than toting
> a big monitor around.

hmm, not sure on that one.

--
Ethan Benson
http://www.alaska.net/~erbenson/

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: Serial Console on XServe and yaboot???

[Bill Fink]

Hi Ethan,

On Thu, 13 Mar 2003, Ethan Benson wrote:

> On Thu, Mar 13, 2003 at 10:29:01PM -0500, Bill Fink wrote:
> >
> > Thanks a bunch for the info!  Using this method, with scca instead
> > of ttya, and a baud rate of 57600 (using a laptop), I was able to
> > verify this basically works.  The initial menu that asks you what
> > you want to boot (Linux, MacOS 9, MacOS X, etc) still goes to the
> > screen (at least it does if you have a screen attached) but the
>
> yes this is because i had to write all my text directly to the
> framebuffer, apple takes all kinds of special efforts to prevent
> `archaic peecee text' from showing up on the screen...  this problem
> should be fixed in yaboot 2.0
>
> i don't consider it too serious right now since if your doing serial
> console your probably not running any macos.
>
> you could probably fix this easily enough for your setup by altering
> the `.printf' definition in ofboot.

It's not a big deal since I only want to run Linux at the moment.

> > yaboot menu where you select the Linux kernel to boot does show
> > up on the serial port of the XServe, and this is what I'm most
> > interested in.  Now if I can just figure out how to set the baud
> > rate of the serial console for OF to 38400 or less to make my
> > console server happy, I'd be in business.  If nothing else I can
> > use the laptop approach which is at least a lot easier than toting
> > a big monitor around.
>
> hmm, not sure on that one.

I figured it out.  I just set the OpenFirmware parameters input-device
and output-device to scca:38400 and it worked fine (except it put my
window into reverse video mode for some reason).

						-Thanks again

						-Bill

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