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SubjectRe: The zen of kernel virtual addresses
On Sat, Oct 21, 2000 at 01:37:26PM -0600, Jonathan Corbet wrote:
> physical address
> An address as known by the low-level hardware. In the modern
> world, these can be 64-bit quantities, even on 32-bit systems.
> These are the addresses used by /dev/mem - which appears to work
> only for low memory.

A phyical address is the address the CPU uses to talk to memory. It is not
necessarily the same kind of address a device uses to see memory: they use
bus addresses. The simple case is bus address == physical address, but
there are many variations. Systems with an IOMMU (or equiv) present devices
with a completely different view of system memory.

J
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