1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/display.c Sun May 28 19:03:58 2017 +0200
1.3 @@ -0,0 +1,58 @@
1.4 +/*
1.5 + * Write to display memory.
1.6 + *
1.7 + * Copyright (C) 2017 Paul Boddie <paul@boddie.org.uk>
1.8 + *
1.9 + * This program is free software: you can redistribute it and/or modify
1.10 + * it under the terms of the GNU General Public License as published by
1.11 + * the Free Software Foundation, either version 3 of the License, or
1.12 + * (at your option) any later version.
1.13 + *
1.14 + * This program is distributed in the hope that it will be useful,
1.15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 + * GNU General Public License for more details.
1.18 + *
1.19 + * You should have received a copy of the GNU General Public License
1.20 + * along with this program. If not, see <http://www.gnu.org/licenses/>.
1.21 + */
1.22 +
1.23 +#include <stdint.h>
1.24 +#include "mips.h"
1.25 +#include "vga.h"
1.26 +
1.27 +void init_framebuffer_with_pattern()
1.28 +{
1.29 + uint32_t *addr = (uint32_t *) KSEG1_BASE;
1.30 + uint32_t base, value;
1.31 + uint16_t x, y;
1.32 + uint8_t row, offset;
1.33 +
1.34 + for (y = 0; y < LINE_COUNT; y++)
1.35 + {
1.36 + /* Start each line with a base value. */
1.37 +
1.38 + row = y / 16;
1.39 + base = (row << 26) | (row << 18) | (row << 10) | (row << 2);
1.40 +
1.41 + /* Set the intensity bit on every other palette row. */
1.42 +
1.43 + if (row % 2) base |= 0x80808080;
1.44 +
1.45 + for (x = 0; x < LINE_LENGTH; x += 4)
1.46 + {
1.47 + /* Combine the base value with the offset. */
1.48 +
1.49 + offset = x / 20;
1.50 + value = base | (offset << 24) | (offset << 16) | (offset << 8) | offset;
1.51 +
1.52 + /* Store the value. */
1.53 +
1.54 + *addr = value;
1.55 +
1.56 + /* Access the next word. */
1.57 +
1.58 + addr++;
1.59 + }
1.60 + }
1.61 +}