Re: Linux 2.1 Virtual Memory problem

David Howells (
Wed, 21 Jan 1998 09:18:52 GMT

>> Well, not actually a bug, but can someone help me with a small problem... To
>> summarise, I need to be able to map physical address 0xFFFFD000 to virtual
>> memory from kernel space.
>No you don't. You probably mean FFFF:D000 in 8086 segmented
>mode... This would be another address in 32-bit mode. AFAIK
>there are no BIOSes with an adress near 4G :-)

Yes, I do... The GET_ESCD_INFO call in the PnP BIOS16 routines returns a
32-bit address representing the base of the NVRAM in the physical memory
map. You are expected to construct a 16-bit/32-bit protected mode segment that
covers 64K starting at this point (in my example, I have to shorten it to
0x3000 bytes).

Anyway... it now works through the use of ioremap()

David Howells