[gentoo-user] scrollback using framebuffer

[Maxim Wexler]

Hi group,

I'm using the nvidia framebuffer(CONFIG_FB_NVIDIA=y) but I can't get
scrollback to work for more than a few lines. I've added
'fbcon=scrollback:128' to my kernel line in grub.conf but scrollback
is still disabled.

Is there some nvidia specific way to do this?

[Alan McKinnon]

Yes, use vesa. It's slow at high res, but works.

The nvidia framebuffer does not work with nvidia-drivers

--
alan dot mckinnon at gmail dot com

[Maxim Wexler]

Yeah, I found that out just after mailing the above. But now that I'm using vesa
how do I enable scrollback? 'fbcon=scrollback:128' in the grub kernel
line doesn't work. It's enabled in the kernel and works fine without
the fb, if that matters.

mw

[Justin]

Ty this here

│ CONFIG_VGACON_SOFT_SCROLLBACK_SIZE:

│
│

│
│ Enter the amount of System RAM to allocate for the scrollback

│
│ buffer. Each 64KB will give you approximately 16 80x25

│
│ screenfuls of scrollback buffer

│
│

│
│ Symbol: VGACON_SOFT_SCROLLBACK_SIZE [=256]

│
│ Prompt: Scrollback Buffer Size (in KB)

│
│ Defined at drivers/video/console/Kconfig:37

│
│ Depends on: HAS_IOMEM && VT && VGACON_SOFT_SCROLLBACK

│
│ Location:

│
│ -> Device Drivers

│
│ -> Graphics support

│
│ -> Console display driver support

│
│ -> VGA text console (VGA_CONSOLE [=y])

│
│ -> Enable Scrollback Buffer in System RAM
(VGACON_SOFT_SCROLLBACK [=y])

│

I am using 256kb with 1050x1680 resolution.

[Alan McKinnon]

It JustWorked for me. My relevant settings:

CONFIG_FB=y
CONFIG_FB_BOOT_VESA_SUPPORT=y
CONFIG_FB_CFB_FILLRECT=y
CONFIG_FB_CFB_COPYAREA=y
CONFIG_FB_CFB_IMAGEBLIT=y
CONFIG_FB_VESA=y
CONFIG_VGACON_SOFT_SCROLLBACK=y
CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=256

I have no settings for scrollback on the kernel command line, just this to set
the resolution etc:

vga=0x37D ywrap mtrr:4

[Maxim Wexler]

>
> CONFIG_FB=y
> CONFIG_FB_BOOT_VESA_SUPPORT=y
> CONFIG_FB_CFB_FILLRECT=y
> CONFIG_FB_CFB_COPYAREA=y
> CONFIG_FB_CFB_IMAGEBLIT=y
> CONFIG_FB_VESA=y
> CONFIG_VGACON_SOFT_SCROLLBACK=y
> CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=256

Identical to mine.

> I have no settings for scrollback on the kernel command line, just this to
> set
> the resolution etc:
>
> vga=0x37D ywrap mtrr:4

Sure about this? 0x37D is not a recognized mode. Are you missing some
punctuation?

my line is: video=vesafb:ywrap,mtrr vga=0x318. Is this syntax
correct? There seems to be a variety out there. Mine only scrolls a
few lines, doesn't matter If I give scrollback 128 or 256k. But there
are no errors, so I must be doing something right. Tried ypan too, no
luck.

mw

[Alan McKinnon]

On Tuesday 17 November 2009 07:48:21 Maxim Wexler wrote:
> > CONFIG_FB=y
> > CONFIG_FB_BOOT_VESA_SUPPORT=y
> > CONFIG_FB_CFB_FILLRECT=y
> > CONFIG_FB_CFB_COPYAREA=y
> > CONFIG_FB_CFB_IMAGEBLIT=y
> > CONFIG_FB_VESA=y
> > CONFIG_VGACON_SOFT_SCROLLBACK=y
> > CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=256
>
> Identical to mine.
>
> > I have no settings for scrollback on the kernel command line, just this
> > to set
> > the resolution etc:
> >
> > vga=0x37D ywrap mtrr:4
>
> Sure about this? 0x37D is not a recognized mode. Are you missing some
> punctuation?

Nope, that's exactly how it is in grub. I have a 1920x1440 screen and I get as
many 8x8 characters as can fit

I got the 0x37D parameter by the table shown with vga=ask

> my line is: video=vesafb:ywrap,mtrr vga=0x318. Is this syntax
> correct? There seems to be a variety out there. Mine only scrolls a
> few lines, doesn't matter If I give scrollback 128 or 256k. But there
> are no errors, so I must be doing something right. Tried ypan too, no
> luck.

And I get 32k worth of scrollback. There's a setting for this in menuconfig:

Device Drivers -> Graphics support -> Console display driver support

what is yours set to?

I must admit, the fb situation is very confusing and the Documentation
directory seems to be a mixture of old, new, wrong and just flat out obsolete
stuff. One has to read the code to find out what is supported it seems