Login prompt on a video console instead of serial port?

Login prompt on a video console instead of serial port?

[Timur Tabi]

I'm using a Freescale P1022DS (PowerPC e500 core) system, which has a built-in
video controller.  I have a framebuffer driver that works fine, and if I add
"video=fslfb:1280x1024-32@60,monitor=0 console=tty0" to the command-line, then
*most* of the kernel boot log appears on the serial port and the video display.

However, the login prompt is always on the serial port.  This happens even if I
delete the "console=ttyS0,115200" from the command-line.  I presume this is
because the "linux,stdout-path" property in the device tree always points to a
serial port node.

So my question is: what do I need to do get the login prompt on the video
console?  That is, stdout goes to /dev/fb0 but stdin is still from /dev/ttyS0.
I presume I need to direct "linux,stdout-path" to the fslfb node in the device
tree, but there doesn't appear to be support for "linux,stdin-path".

-- 
Timur Tabi
Linux kernel developer at Freescale

Re: Login prompt on a video console instead of serial port?

[McClintock Matthew-B29882]

Don't you have to spawn a terminal on the framebuffer for the login?
Right now getty spawns the login on the serial port via /etc/inittab.
Something similiar is probably needed for the framebuffer.

-M



On Mon, May 2, 2011 at 2:30 PM, Timur Tabi <timur@freescale.com> wrote:
> I'm using a Freescale P1022DS (PowerPC e500 core) system, which has a built-in
> video controller.  I have a framebuffer driver that works fine, and if I add
> "video=fslfb:1280x1024-32@60,monitor=0 console=tty0" to the command-line, then
> *most* of the kernel boot log appears on the serial port and the video display.
>
> However, the login prompt is always on the serial port.  This happens even if I
> delete the "console=ttyS0,115200" from the command-line.  I presume this is
> because the "linux,stdout-path" property in the device tree always points to a
> serial port node.
>
> So my question is: what do I need to do get the login prompt on the video
> console?  That is, stdout goes to /dev/fb0 but stdin is still from /dev/ttyS0.
> I presume I need to direct "linux,stdout-path" to the fslfb node in the device
> tree, but there doesn't appear to be support for "linux,stdin-path".

Re: Login prompt on a video console instead of serial port?

[Timur Tabi]

McClintock Matthew-B29882 wrote:
> Don't you have to spawn a terminal on the framebuffer for the login?

I suppose, but I don't know how to do that.  And although that would technically
answer the question in the subject of this thread, I still would have *some*
boot output on the serial port.  It would be nice if I could get all of stdout
on the video display, and all of stdin from the serial port.

> Right now getty spawns the login on the serial port via /etc/inittab.
> Something similiar is probably needed for the framebuffer.

getty appears to work only with serial devices, since it insists on a baud rate
as one of the parameters.

-- 
Timur Tabi
Linux kernel developer at Freescale

Re: Login prompt on a video console instead of serial port?

[Benjamin Herrenschmidt]

On Mon, 2011-05-02 at 15:02 -0500, Timur Tabi wrote:
> McClintock Matthew-B29882 wrote:
> > Don't you have to spawn a terminal on the framebuffer for the login?
> 
> I suppose, but I don't know how to do that.  And although that would technically
> answer the question in the subject of this thread, I still would have *some*
> boot output on the serial port.  It would be nice if I could get all of stdout
> on the video display, and all of stdin from the serial port.

I don't think we have a way to do that unless you can make a serial
"keyboard" device in the input layer. The VT layer will only get its
input from such a thing, maybe that does exist in the depth of legacy
code in there but it has nothing to do with your device-tree.

> > Right now getty spawns the login on the serial port via /etc/inittab.
> > Something similiar is probably needed for the framebuffer.
> 
> getty appears to work only with serial devices, since it insists on a baud rate
> as one of the parameters.

No, or no existing distro would work :-)

Just fake a baudrate for the tty's

Cheers,
Ben.

Re: Login prompt on a video console instead of serial port?

[Grant Likely]

On Mon, May 2, 2011 at 1:30 PM, Timur Tabi <timur@freescale.com> wrote:
> I'm using a Freescale P1022DS (PowerPC e500 core) system, which has a built-in
> video controller.  I have a framebuffer driver that works fine, and if I add
> "video=fslfb:1280x1024-32@60,monitor=0 console=tty0" to the command-line, then
> *most* of the kernel boot log appears on the serial port and the video display.
>
> However, the login prompt is always on the serial port.  This happens even if I
> delete the "console=ttyS0,115200" from the command-line.  I presume this is
> because the "linux,stdout-path" property in the device tree always points to a
> serial port node.
>
> So my question is: what do I need to do get the login prompt on the video
> console?  That is, stdout goes to /dev/fb0 but stdin is still from /dev/ttyS0.
> I presume I need to direct "linux,stdout-path" to the fslfb node in the device
> tree, but there doesn't appear to be support for "linux,stdin-path".

Look in /etc/inittab.  That's usually where the login gettys are specified.

g.

>
> --
> Timur Tabi
> Linux kernel developer at Freescale
>
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>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.