Date: Wed, 19 Jun 1996 16:30:36 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: msaal@qosnet.com (Michael Saal) Cc: questions@FreeBSD.org Subject: Re: ?: allocating physical memory for a driver Message-ID: <199606192330.QAA14478@phaeton.artisoft.com> In-Reply-To: <31C80975.41C67EA6@qosnet.com> from "Michael Saal" at Jun 19, 96 02:06:45 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> I am writing a driver for a bus mastering ISA card.
>
> How do I allocate physical memory and make sure that is located below
> the 16M boundry addressable by the ISA bus?
>
> Is malloc("memory size", M_DEVBUF, M_NOWAIT) sufficient? If it is I
> don't see how you can make sure the memory is in the right range with
> out testing the resulting pointer.
Look at the DMA stuff in (for instance) the aha1542 driver; it's pretty
straight-forward. If you use the standard routines, bouncing will
be done for you.
Terry Lambert
terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199606192330.QAA14478>