[SeaBIOS] [PATCH] mark VBE mapping as reserved in e820

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Sun Jan 24 17:10:46 CET 2010


On 24.01.2010 16:32, Izik Eidus wrote:
> On Sun, 24 Jan 2010 15:26:55 +0100
> Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> wrote:
>
>   
>>> So we can see that even the acpi spec example mark the LFB region as reserved.
>>>   
>>>       
>> No, the memory hole is marked as reserved. The LFB region is not listed
>> above.
>>     
>
> But how in case you use vesa with isa, windows will know it cant remap pci devices
> into that physical address?
>   

ISA only supports 24 bit addresses anyway, so you can't map any resource
of an ISA card above 16 MByte. That means an ISA device will never use
the region at 0xE0000000.

http://www.microsoft.com/whdc/connect/pci/isa-bus.mspx implies that the
ISAPNP interface of the BIOS is available for querying any resources, so
in case you have an EISA device and if that device can indeed use full
32 bit addressing (very unusual for EISA hardware) you can still ask the
BIOS to retrieve the location of any memory regions.

Regards,
Carl-Daniel

-- 
Developer quote of the year:
"We are juggling too many chainsaws and flaming arrows and tigers."




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