Date: Thu, 13 Oct 2005 10:52:53 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-drivers@freebsd.org Subject: Re: reference drivers Message-ID: <200510131052.54692.jhb@freebsd.org> In-Reply-To: <434D7A42.1080005@endace.com> References: <434983A6.8040403@endace.com> <200510121532.54474.jhb@freebsd.org> <434D7A42.1080005@endace.com>
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On Wednesday 12 October 2005 05:04 pm, Michael Honeyfield wrote: > John Baldwin wrote: > >On Sunday 09 October 2005 04:55 pm, Michael Honeyfield wrote: > >>Hello all, > >> > >>I have been working on a small project that involes writting a drver for > >>FreeBSD. I have used this link as my reference for my driver: > >> > >>http://www.ben.com/minipci/driver.php > >> > >>Now, after my modifications, I can load the kernel module fine. However, > >>the mmap function is not even called. Is the mmap function used inside > >>this diver the correct way map registers from kernel space to user space? > > > >Yes. It should be called when an application does an mmap() on an fd > > returned by open()'ing the file in /dev. > > Ok, good to know I am on the right path. > > Where is a good place to look if the foo_mmap() is not actually called? > > I use this routine as a test for mapping a register into user space: > > fd = open( "/dev/bar0", O_RDWR ); > reg = mmap(NULL, 0x10000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); > if( reg == MAP_FAILED) { > fprintf( stderr, "can't mmap bar!\n" ); > exit(1); > } > > the code takes an arg, and the register I am selecting is there. The > above code snippet works on Linux. You need to make sure d_mmap in your cdevsw is mapped to your mmap function. How do you know that your mmap routine is not being called? Did you add a printf or some such? Did you do so before any error checking that would cause an early return from the function? -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.orghome | help
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