Mapping Video BIOS?

M. Warner Losh imp at
Sat Jul 26 18:52:29 PDT 2003

In message: <20030727010938.GF45069 at>
            "Greg 'groggy' Lehey" <grog at> writes:
: On Saturday, 26 July 2003 at 18:44:43 -0600, M. Warner Losh wrote:
: > In message: <20030727002138.GD45069 at>
: >             "Greg 'groggy' Lehey" <grog at> writes:
: >> On Saturday, 26 July 2003 at 11:27:06 -0600, M. Warner Losh wrote:
: >>> In message: <20030726080217.GB45069 at>
: >>>             "Greg 'groggy' Lehey" <grog at> writes:
: >>>> machine doesn't have a serial port, so I can't apply a kernel debugger
: >>>> to find out what's going on.
: >>>
: >>> Does it have a firewire port?
: >>
: >> Yes.  How can I use that?
: >
: > If you have a second machine with firewire, then you can use the
: > firewire port as your console.  Look at /usr/ports/devel/dcons.  It is
: > one of the under-publicized cool features from Japan (Thanks
: > Shimokawa-san!).
: Ah, good stuff.  I'll have to check if it also works with gdb.
: Unfortunately, this is my only machine with firewire.  I was wondering
: if there were USB/conventional serial converters that I could use.

None of them support console access, as far as I know.

: >> I had also expected that you could shed some light on the BIOS mapping
: >> issue.  Since my last message I've become pretty sure that it must be
: >> something to do with the chip set setup.  Is it possible that we're
: >> not mapping the entire area 0xc0000 to 0xfffff?
: >
: > I'm not sure what you mean by this question.  Since OLDCARD works, and
: > requires read/write access to that physical memory range, I doubt that
: > it is unmapped.
: I'm not sure at what level.  I suspect that something in the chipset
: is turning off that area of memory, or mapping something else to it.
: The dump from Microsoft shows that there's another BIOS at 0xcf000,
: but what I have mapped in memory shows only 0xff up to address
: 0xd0000, where I find another BIOS signature:
: 0x28377fe0:     0xffffffff      0xffffffff      0xffffffff      0xffffffff
: 0x28377ff0:     0xffffffff      0xffffffff      0xffffffff      0xffffffff
: 0x28378000:     0xe80caa55      0x4ecb14c8      0x0000033b      0x00000000
: 0x28378010:     0x00000000      0x00200000      0x00600040      0x90c08b2e
: 0x28378020:     0x49444e55      0x0000ea16      0x0c9d0201      0xad100800

Typically, there are a number of different ROM sections.  The orm
driver searches for these things out.  Does it report anything

: > It may be the case that we aren't setting things up so that XFree86
: > can call the BIOS, but given that we used PCIBIOS before ACPI, it
: > seems unlikely.
: Well, this is a new laptop, so it's possible that something *is*
: getting set up incorrectly.



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