EPIA Howto Update

[Mark Wilkinson]

Hello All,
    Just a quick note to say that I've updated my EPIA howto to include a little  
section for the brave on enabling the onboard VGA.

This is based on Sone Takeshi's work.

Thanks to Andrew Ip for committing the update to CVS.

Regards
Mark.

[SONE Takeshi]

On Fri, Jul 18, 2003 at 01:29:48AM +0100, Mark Wilkinson wrote:
> Just a quick note to say that I've updated my EPIA howto to include a little  
> section for the brave on enabling the onboard VGA.
>
> This is based on Sone Takeshi's work.
>
> Thanks to Andrew Ip for committing the update to CVS.

Hi Mark,
Thank you for your work.

Perhaps everyone already forgets about it, but I was asked by Ron
for a HOWTO on EPIA+VGA.
I started it, but it isn't finished. (I was fiddling with BOOT_IDE etc
to include in my documentation...)
Now that your HOWTO covers VGA, everything is OK.

Some points...

- Line 37-40:
    NOTE: At present, the epia can be booted with a serial console. Power
      management to turn off the power is not available, neither is the
      video bios. Memeory is currenly hard coded to report 64M - you must
      have at least this much memory.

You can use video console once VGA is enabled (option VIDEO_CONSOLE=1).
It isn't very useful however, since VGA initialization is almost at the
end of LinuxBIOS execution. 
Memory configuration is also fixed already.

- Line 364-367:
                0 - Disable Framebuffer
                1 - 1 Mbyte
                2 - 2 Mbytes
                8 - 8 Mbytes

This is incorrect. Valid values are 2, 4, and 8 (MB).
To disable framebuffer, remove the option HAVE_FRAMEBUFFER.

Also, now I use folowing lines in the config for the VGA BIOS image to be
patched in the romimage:
    option ZKERNEL_START=0xfffc0000
    option VGABIOS_START=0xfffe0000
    addaction romimage dd if=/path/to/vgabios.bin of=romimage bs=65536 \
    seek=2 conv=sync conv=notrunc
This way you don't have to handcraft the vga+eb payload.

[Mark Wilkinson]

Hi Sone,

Thanks for the comments, looks like an update to the update will be on it's 
way shortly !

On Friday 18 Jul 2003 05:56, SONE Takeshi wrote:
> On Fri, Jul 18, 2003 at 01:29:48AM +0100, Mark Wilkinson wrote:
> > Just a quick note to say that I've updated my EPIA howto to include a
> > little section for the brave on enabling the onboard VGA.
> >
> > This is based on Sone Takeshi's work.
> >
> > Thanks to Andrew Ip for committing the update to CVS.
>
> Hi Mark,
> Thank you for your work.
>
> Perhaps everyone already forgets about it, but I was asked by Ron
> for a HOWTO on EPIA+VGA.
> I started it, but it isn't finished. (I was fiddling with BOOT_IDE etc
> to include in my documentation...)
> Now that your HOWTO covers VGA, everything is OK.
>
> Some points...
> Line 37-40:
>   NOTE: At present, the epia can be booted with a serial console. Power
>    management to turn off the power is not available, neither is the
>    video bios. Memeory is currenly hard coded to report 64M - you must
>    have at least this much memory.
>
> You can use video console once VGA is enabled (option VIDEO_CONSOLE=1).
> It isn't very useful however, since VGA initialization is almost at the
> end of LinuxBIOS execution.
> Memory configuration is also fixed already.

Oops, forgot all about the memory configuration being fixed, and I haven't had 
a chance to play with the VIDEO_CONSOLE=1 option yet (old story about not 
being enough hours in the day... :-)
> Line 364-367:
>               0 - Disable Framebuffer
>               1 - 1 Mbyte
>               2 - 2 Mbytes
>               8 - 8 Mbytes
>
> This is incorrect. Valid values are 2, 4, and 8 (MB).
> To disable framebuffer, remove the option HAVE_FRAMEBUFFER.

Will correct that, although what I can remember from the northbridge docs is 
that a setting of 0 also disables the framebuffer - perhaps this option is 
really a 'have framebuffer, but don't share with it memory option'
> Also, now I use folowing lines in the config for the VGA BIOS image to be
> patched in the romimage:
>     option ZKERNEL_START=0xfffc0000
>     option VGABIOS_START=0xfffe0000
>     addaction romimage dd if=/path/to/vgabios.bin of=romimage bs=65536 \
>    seek=2 conv=sync conv=notrunc
> This way you don't have to handcraft the vga+eb payload.

so this copies the vgabios into the rom image after the payload (not the 
otherway around) doesn't copying 65536 bytes to 0xfffe000 overwrite the 
Linuxbios part of the rom image ? or is that done afterwards, in which case 
the LinuxBIOS would overwrite part of the vgabios image... althought, I think 
the VGA bios is only 48K in size isn't it !

I'll have to try this, just to get my head around what's happening !

Regards
Mark.

[SONE Takeshi]

On Fri, Jul 18, 2003 at 07:20:22AM +0100, Mark Wilkinson wrote:
> Will correct that, although what I can remember from the northbridge docs is 
> that a setting of 0 also disables the framebuffer - perhaps this option is 
> really a 'have framebuffer, but don't share with it memory option'

vgainit.inc has #if's to examine the value to choose the value for 
the northbridge register, it cause #error if it's 0.
> > option ZKERNEL_START=0xfffc0000
> > option VGABIOS_START=0xfffe0000
> > addaction romimage dd if=/path/to/vgabios.bin of=romimage bs=65536 \
> >
> > seek=2 conv=sync conv=notrunc
> so this copies the vgabios into the rom image after the payload (not the 
> otherway around) doesn't copying 65536 bytes to 0xfffe000 overwrite the 
> Linuxbios part of the rom image ? or is that done afterwards, in which case 
> the LinuxBIOS would overwrite part of the vgabios image... althought, I think 
> the VGA bios is only 48K in size isn't it !

It copies vgabios.bin at 128-192KB of romimage.
LinuxBIOS lives at 192-256KB.
128KB space at the beginning is left for payload.

[ron minnich]

suggestion: next week the config tool should be basically done for
freebios2. You folks cold look at converting DRAM code to C and porting
the EPIA code to freebios2. It is about 100 times easier to code this
stuff up in C.

ron

[SONE Takeshi]

On Fri, Jul 18, 2003 at 08:08:24AM -0600, ron minnich wrote:
> suggestion: next week the config tool should be basically done for
> freebios2. You folks cold look at converting DRAM code to C and porting
> the EPIA code to freebios2. It is about 100 times easier to code this
> stuff up in C.

My raminit code does not use SPD. It does "probe" instead. 
(I first saw this method in NetBSD BIOS)
In C, SPD stuff should easily be done, but I'm not very excited
to adapt it to EPIA since I'm quite happy with current probing code.

Probing is implemented with fewer assembly code (and some in C),
but has disadvantage that it can't detect timing parameters
(PC100/133, CL2/CL3) at runtime.
Still it should be done in C 10 times easier though.