Messages in this thread | | | Date | Fri, 9 Apr 2010 23:54:13 +0100 | From | Alan Cox <> | Subject | Re: [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86_32 |
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> No they're not. The 0xa0000...0xbffff range has been a legacy video > area since the very first PC (although the first PC only used > 0xb0000..0xbffff, 0xa0000..0xbffff was declared reserved at that time.)
Depending on your definition of "PC". Quite a few early MSDOS systems had video elsewhere. Some embedded systems without video use the space for other stuff. Lots of ISA 386/486 PCs had cards borrowing the unused bits of video space.
> I'm wondering what those legitimate reasons are. This is particularly > so since it affects our ability to deal with very early errors, long > before we have enumerated anything. At this point we can at least lay > down bytes in the video area and hope the user can see them.
Thats why you have the bios equipment byte and video queries.
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