bruce@garfield.UUCP (Bruce Keats) (07/12/84)
[Reach out and grep someone] I am going to write a device driver for a Ramtek RM-4060 Graphics System on a Vax 750 running 4.2BSD. Before I go blindly into to this, I have some questions that need to be answered. I am thinking of setting it up such that the Ramtek would be a character device. This way a user could do open/read/write/ioctl/ close to access the device. Is this the best way to do it? Since the Ramtek does DMA, any method I use will still would have to handle setting up the UBA. Is there a problem with setting up the UBA memory map so that it can DMA from user space? If this isn't possible, how is buffer allocation done in 4.2? How does one set up the UBA for DMA under 4.2? In-real-life: Bruce Keats, Memorial Univ. of Nfld., St. John's, Nfld., Can. UUCP: {utcsrgv,ihnp4,akgua,allegra,cbosgd,philabs}!garfield!bruce