[Info-vax] Device Driver Kernel-User Buffer Mapping

[Roger Ivie]

On Sunday, May 9, 2021 at 6:44:32 PM UTC-7, lui... at gmail.com wrote:
> Specifically, the problem is that IOC$MAP_IO returns a handle value which I can't figure
> out how to resolve to a virtual address, so I don't know where in system memory my PCI
> device is mapped. Unless the "magic number" it returns happens to be a pointer to an
> IOHANDLE or something.

the iohandle holds the *physical* address at which your device is mapped. you use that to create the page frame number you need to hand to the appropriate flavor of $crmpsc to create a pfn-mapped section. $crmpsc gives you the virtual address.
-- 
roger ivie
roger.ivie at gmail.com