Initial optimized version LCD display emulation.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

1 files changed, 145 insertions, 0 deletions

diff --git a/qtmips_machine/lcddisplay.cpp b/qtmips_machine/lcddisplay.cpp
new file mode 100644
index 0000000..1d96b9d
--- /dev/null
+++ b/qtmips_machine/lcddisplay.cpp
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*******************************************************************************
+ * QtMips - MIPS 32-bit Architecture Subset Simulator
+ *
+ * Implemented to support following courses:
+ *
+ *   B35APO - Computer Architectures
+ *   https://cw.fel.cvut.cz/wiki/courses/b35apo
+ *
+ *   B4M35PAP - Advanced Computer Architectures
+ *   https://cw.fel.cvut.cz/wiki/courses/b4m35pap/start
+ *
+ * Copyright (c) 2017-2019 Karel Koci<cynerd@email.cz>
+ * Copyright (c) 2019      Pavel Pisa <pisa@cmp.felk.cvut.cz>
+ *
+ * Faculty of Electrical Engineering (http://www.fel.cvut.cz)
+ * Czech Technical University        (http://www.cvut.cz/)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301, USA.
+ *
+ ******************************************************************************/
+
+#include "lcddisplay.h"
+
+using namespace machine;
+
+LcdDisplay::LcdDisplay() {
+    size_t need_bytes;
+    fb_size = 0x4b000;
+    fb_bpp = 16;
+    fb_width = 480;
+    fb_height = 320;
+    if (fb_bpp > 12) {
+        fb_linesize = ((fb_bpp + 7) >> 3) * fb_width;
+    } else {
+        fb_linesize = (fb_bpp * fb_width + 7) >> 3;
+    }
+    need_bytes = fb_linesize * fb_height;
+
+    if (fb_size <= need_bytes)
+        fb_size = need_bytes;
+
+    fb_data = new uchar[fb_size];
+    std::fill(fb_data, fb_data + fb_size, 0);
+}
+
+LcdDisplay::~LcdDisplay() {
+    if (fb_data != nullptr)
+        delete[] fb_data;
+}
+
+std::uint32_t LcdDisplay::pixel_address(uint x, uint y)
+{
+    std::uint32_t address;
+    address = y * fb_linesize;
+    if (fb_bpp > 12)
+        address += x * ((fb_bpp + 7) >> 3);
+    else
+        address += x * fb_bpp / 8;
+
+    return address;
+}
+
+
+bool LcdDisplay::wword(std::uint32_t address, std::uint32_t value) {
+    address &= ~3;
+    uint x, y, r, g, b;
+    std::uint32_t c;
+    std::uint32_t last_addr = address + 3;
+    std::uint32_t pixel_addr;
+
+    if (address + 3 >= fb_size)
+        return 0;
+#if 0
+    printf("LcdDisplay::wword address 0x%08lx data 0x%08lx\n",
+           (unsigned long)address, (unsigned long)value);
+#endif
+
+    fb_data[address + 0] = (value >> 24) & 0xff;
+    fb_data[address + 1] = (value >> 16) & 0xff;
+    fb_data[address + 2] = (value >> 8) & 0xff;
+    fb_data[address + 3] = (value >> 0) & 0xff;
+
+    y = address / fb_linesize;
+    if (fb_bpp > 12)
+        x = (address - y * fb_linesize) / ((fb_bpp + 7) >> 3);
+    else
+        x = (address - y * fb_linesize) * 8 / fb_bpp;
+
+    while ((pixel_addr = pixel_address(x, y)) <= last_addr) {
+        c = fb_data[pixel_addr] << 8;
+        c |= fb_data[pixel_addr + 1];
+
+        r = ((c >> 11) & 0x1f) << 3;
+        g = ((c >> 5) & 0x3f) << 2;
+        b = ((c >> 0) & 0x1f) << 3;
+
+        emit pixel_update(x, y, r, g, b);
+
+        if (++x >= fb_width) {
+            x = 0;
+            y++;
+        }
+    }
+
+    emit write_notification(address, value);
+
+    return true;
+}
+
+std::uint32_t LcdDisplay::rword(std::uint32_t address, bool debug_access) const {
+    address &= ~3;
+    (void)debug_access;
+    std::uint32_t value;
+
+    if (address + 3 >= fb_size)
+        return 0;
+
+    value = (std::uint32_t)fb_data[address + 0] << 24;
+    value |= (std::uint32_t)fb_data[address + 1] << 16;
+    value |= (std::uint32_t)fb_data[address + 2] << 8;
+    value |= (std::uint32_t)fb_data[address + 3] << 0;
+
+#if 0
+    printf("LcdDisplay::rword address 0x%08lx data 0x%08lx\n",
+           (unsigned long)address, (unsigned long)value);
+#endif
+
+    emit read_notification(address, &value);
+
+    return value;
+}