On Wed, Mar 19, 2008 at 02:25:36PM -0400, Leichter, Jerry wrote: [This has been thrashed out on other lists.]
> Just how would that help? As I understand it, Firewire and PCMCIA > provide a way for a device to access memory directly. The OS doesn't > have to do anything - in fact, it *can't* do anything. The OS can program the Firewire controller not to allow DMA. > The only possible protection here is at the hardware level: The > external interface controller must be able to run in a mode which > blocks externally-initiated memory transactions. Unfortunately, > that may not be possible for some controllers. Sure, the rules for > (say) SCSI might say that a target is only supposed to begin sending > after a request from an initiator - but it would take a rather > sophisticated state machine to make sure to match things up properly, > especially on a multi-point bus. Isn't what you're describing here an IOMMU? David. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]