Re: [Fastboot] Re: Announce: dumpfs v0.01 - common RAS output API

Eric W. Biederman
2004-07-29T16:42:44Z

"Martin J. Bligh" <mbligh@aracnet.com> writes:

> IIRC, what Adam did is to relocate the bottom 16MB of mem into the
> reserved buffer and execute into the bottom 16MB. Yes, that probably does
> leave some DMA issues that we should fix up as you suggest above, but I
> think it's good enough for a first pass at the problem.

Probably. I have witnessed network RX causing memory corruption,
before the kexec code started downing the network interfaces on
the user space side. I suspect data capture from sound cards or
video capture cards would have the same issue.

The way I have observed this in the past is to kexec memtest86,
on a machine with known good memory, and then attempt to ping it :)

What especially worries me about the low 16MB is that it is the
DMA zone for ISA devices. Old sound cards in particular. Most
of that is output but....

Eric