From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4CB36658.5000200@domain.hid> Date: Mon, 11 Oct 2010 21:32:40 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4CB35360.6080003@domain.hid> <4CB36314.6090109@domain.hid> <4CB36627.5040602@domain.hid> In-Reply-To: <4CB36627.5040602@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] rt_io_get_region List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Roger Carns Cc: Xenomai help Roger Carns wrote: > > On 10/11/2010 3:18 PM, Gilles Chanteperdrix wrote: >> Roger Carns wrote: >>> Does rt_io_get_region function be called from user space and does >>> it return a user space address and if so how is it return? Also >>> is there doc out there someplace on usage of this function. >> rt_io_get_region is a user-space mapping of >> request_mem_regio/request_io_region. As such, yes, it may be called >> from user-space. And no, it does not return address. What it >> returns is a cookie that may be passed to rt_io_put_region to free >> the used memory. >> >> In order to map an MMIO region in user-space you should use >> /dev/mem or use ioperm and inl/outl directly if you want to access >> an I/O port. What rt_io_get_region does is to allow you to this >> cleanly with regard to the rest of the system. >> > So, I open the /dev/mem and use the fd returned on the mmap call. But > how do I associate the region defined in the rt_io_get_region with > that fd? The offset passed to mmap is the physical address which you want to map. Please do not forget to CC the maling list. -- Gilles.