1 /* $NetBSD: btreg.h,v 1.1 1995/03/10 01:50:41 gwr Exp $ */ 2 3 /* 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * All advertising materials mentioning features or use of this software 12 * must display the following acknowledgement: 13 * This product includes software developed by the University of 14 * California, Lawrence Berkeley Laboratory. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. All advertising materials mentioning features or use of this software 25 * must display the following acknowledgement: 26 * This product includes software developed by the University of 27 * California, Berkeley and its contributors. 28 * 4. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 * 44 * @(#)btreg.h 8.2 (Berkeley) 1/21/94 45 */ 46 47 /* 48 * Several Sun color frame buffers use some kind of Brooktree video 49 * DAC (e.g., the Bt458, -- in any case, Brooktree make the only 50 * decent color frame buffer chips). 51 * 52 * Color map control on these is a bit funky in a SPARCstation. 53 * To update the color map one would normally do byte writes, but 54 * the hardware takes longword writes. Since there are three 55 * registers for each color map entry (R, then G, then B), we have 56 * to set color 1 with a write to address 0 (setting 0's R/G/B and 57 * color 1's R) followed by a second write to address 1 (setting 58 * color 1's G/B and color 2's R/G). Software must therefore keep 59 * a copy of the current map. 60 * 61 * The colormap address register increments automatically, so the 62 * above write is done as: 63 * 64 * bt->bt_addr = 0; 65 * bt->bt_cmap = R0G0B0R1; 66 * bt->bt_cmap = G1B1R2G2; 67 * ... 68 * 69 * Yow! 70 * 71 * Bonus complication: on the cg6, only the top 8 bits of each 32 bit 72 * register matter, even though the cg3 takes all the bits from all 73 * bytes written to it. 74 */ 75 struct bt_regs { 76 u_int bt_addr; /* map address register */ 77 u_int bt_cmap; /* colormap data register */ 78 u_int bt_ctrl; /* control register */ 79 u_int bt_omap; /* overlay (cursor) map register */ 80 }; 81