> > I mean, what services do drivers offer? What services they _need_ to offer? Do > > they just create appropriate device nodes and let the applications to worry about > > using them or do they do some data manipulation or do they offer routines and > > interfaces for applications or what? What should this particular driver do as I > > just want to read/write data. > >
I think for your application running in userland is fine, if kernel programming is likely to be a steep learning curve. You can use nanosleep() to get the timing you need. On Wed, Oct 15, 2003 at 05:13:29PM -0400, Mathew Kanner wrote: > I'm not positive about this but I think that you can do it > from usermode by opening /dev/io (as root) and the use inb, outb > macros defined in cpufunc.h. You can also use i386_get_ioperm() and i386_set_ioperm(). These change the I/O port permission bitmap in the process's Task State Segment (TSS) accordingly, so that you can issue IN/OUT instructions without segfaulting in a similar way to opening /dev/io. The only trouble with /dev/io is that it's an all-or-nothing approach (processes literally can write anywhere in I/O space); better to ask for what you need than ask for everything, IMHO. BMS _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
