yaboot: text mode or graphics mode?

Does anyone knw what happens when we boot into yaboot,whether we are
in text mode or graphics mode? If text mode then wat is the address of
the screen? I need it to print some debug info..bt i either dnt seem
to get the buffer address correct or i m not in text mode as yaboot
has already switched to some other mode...

Regards,
Sumedh

I just found out that openfirmware boots into graphics mode(non-text
mode). Now i wish to switch back to text mode. how do i do this?

On Sat, Dec 20, 2008 at 9:37 PM, sumedh tirodkar
[off-list ref] wrote:

Does anyone knw what happens when we boot into yaboot,whether we are
in text mode or graphics mode? If text mode then wat is the address of
the screen? I need it to print some debug info..bt i either dnt seem
to get the buffer address correct or i m not in text mode as yaboot
has already switched to some other mode...

Regards,
Sumedh

sumedh tirodkar wrote:

I just found out that openfirmware boots into graphics mode(non-text
mode). Now i wish to switch back to text mode. how do i do this?

Unfortunately unless you are running some kind of yaboot-accessible or 
firmware-accessible x86 BIOS emulation, this isn't possible.

--
Matt

Isn't there any other way that i can access the VGA registers? So as
to reconfigure them...

-Sumedh

On Wed, Dec 31, 2008 at 4:15 AM, Matt Sealey [off-list ref] wrote:

sumedh tirodkar wrote:

quoted

I just found out that openfirmware boots into graphics mode(non-text
mode). Now i wish to switch back to text mode. how do i do this?

Unfortunately unless you are running some kind of yaboot-accessible or
firmware-accessible x86 BIOS emulation, this isn't possible.

--
Matt

They should be mapped into PCI address space with the rest, you should 
note though that a bunch of people have asked this a bunch of times and 
the response is usually null.

If you want to output debugging info, try a serial port, or if you're 
still at the point in boot where the OF is still around, you can still 
output to it (check prom_init.c) and if not, the open firmware 
framebuffer console driver is your best friend..

sumedh tirodkar wrote:

Isn't there any other way that i can access the VGA registers? So as
to reconfigure them...

-Sumedh

On Wed, Dec 31, 2008 at 4:15 AM, Matt Sealey [off-list ref] wrote:

quoted

sumedh tirodkar wrote:

quoted

I just found out that openfirmware boots into graphics mode(non-text
mode). Now i wish to switch back to text mode. how do i do this?

Unfortunately unless you are running some kind of yaboot-accessible or
firmware-accessible x86 BIOS emulation, this isn't possible.

--
Matt