Re: [LinuxBIOS] Epia-M patch

[Jun OKAJIMA]

Please let me clear ...

1. You mean, in the end, VGA works. Right?
2. If 1 is yes, X server works also? or not tested yet?
3. How much time it takes to boot?
   Both in vga enabled and disabled?
   Old way of VGA init is slow?

--- Okajima, Jun. Tokyo, Japan.
> I attach a patch file for the Via Epia-m target which makes this target now
> compile and work.
>
> I have tried to keep all changes local to the directories relevent to this
> target i.e.
> mainboard/via/epia-m
> northbridge/via/vt8623
> southbridge/via/vt8623
> southbridge/ricoh
> superio/via/vt1211
> targets/via/epia-m
>
> However there are 4 files which are modified elsewhere in the sources:
> devices/cardbus_device.c - which needed another io resource probing -
>
> comments suggest no-one else is using this anyway
> include/device/cardbus.h - to include another function definition
> cpu/via/model_centaur/model_centaur.c - to add more processor id codes and
>
> to get it to set up mtrr's
> arch/i386/lib/cpu.c - to conditionally test for SMP & IOAPIC systems -
>
> this board/processor has no APIC's and would otherwise fail on the call to
> lapicid()
>
> In addition to making it work again, I have added the following
> functionality:
>
> Dynamic memory sizing - which has been tested so far with:
> 256Mb 1 bank (i.e. single sided)
> 256Mb 2 bank (i.e. double sided)
> 512Mb 2 bank (i.e. double sided)
>
> A minimalist ACPI dsdt table free of any intellectual property and can
>
> thus be distributed with sources.
>
> Compact Flash boot working.
>
> I have also written an EPIA-M howto which I have attached seperately.
>
> Maybe that can get onto the web site.
>
> Things still not resolved:
> I spent a great deal of time trying to get the vga to initialise through the
> emulator, but I have failed. I feel that I now know the workings of the
> emulator inside out, but it would take a good deal more effort to resolve
> the issues.
>
> As an interim solution, therefore, I have re-implemented the old real mode
> vga-bios.c which works a treat on this board. To keep the main source tree
> clean of this, it is implemented locally within the mainboard/via/epia-m
> directory, and in a way which does not require any changes to the main
> source tree (e.g. it implements its own temporary gdt's and idt's). Maybe
> one day I shall return to this problem.
>
> Whilst attempting to get the emulator to work, I had to start using a
> fallback only image for sizing reasons, and this is how the patch is
> configured. Without both real-mode vga and the emulator it may be possible
> to go back to a dual image.
>
> My original epia-m port set up 2 mtrr's over the vga framebuffer and agp
> bridge as per the Award bios, and this makes a noticeable difference in
> performance. Without changing the current mtrr stuff I see no way of making
> a request for these to be set up, and so this version doesn't attempt to. It
> would be nice to see this sort of functionality return into the core if
> anyone is interested - perhaps as another type of memory resource different
> to main memory and non contiguous from main memory. The type of these mtrr's
> is write combining rather than write back as used for main memory.
>
> Nick Barker