* Jeremy Jackson jerj@coplanar.net [070611 17:17]:
My dream is to have a chip specific driver (map driver in MTD terms) which knows the window size the BIOS hardware decoder supports, including the optional enable bits.
One kernel driver per supported chipset? Ouch. That does not make things easy at all.
The chip driver also interacts with Linux /dev/iomem to reflect the current setting of the optional enables.
In the kernel you don't have to use /dev/iomem, you can just inb/outb directly (which is what /dev/iomem does)
It should also update the below 1MB (and maybe below 16MB) aliases in /proc/iomem, according to their actual status in the hardware. For example, the K8 northbridge fixed MTRRs could be disabled, rendering any aliasing of the southbridge or LPC/FWH parts moot (from the processor's perspective at least)
How is this thing done today? Is it part of the e820 table? Or does Linux hardcode that area?
Stefan