kernel: Move video console code

This commit introduces a video console driver to Hyra and replaces
that weird tty.c file used only for video console logic

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 207 insertions, 0 deletions

diff --git a/sys/dev/vcons/vcons.c b/sys/dev/vcons/vcons.c
new file mode 100644
index 0000000..622c7ae
--- /dev/null
+++ b/sys/dev/vcons/vcons.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <dev/vcons/vcons.h>
+#include <dev/vcons/vcons_io.h>
+#include <dev/video/fbdev.h>
+#include <sys/syslog.h>
+#include <sys/cdefs.h>
+#include <string.h>
+
+__MODULE_NAME("kern_vcons");
+__KERNEL_META("$Hyra$: kern_vcons.c, Ian Marco Moffett, "
+              "Hyra video console code");
+
+/* Get x or y values in pixels */
+#define PIX_CPY_X(scrptr) (scr->cpy_x * FONT_WIDTH)
+#define PIX_CPY_Y(scrptr) (scr->cpy_y * FONT_HEIGHT)
+
+static struct vcons_screen *screen = NULL;
+
+static void
+vcons_clear_scr(struct vcons_screen *scr)
+{
+    struct fbdev fbdev = scr->fbdev;
+
+    scr->cpy_x = 0, scr->cpy_y = 0;
+
+    memset(scr->fbdev_mem, scr->bg, (fbdev.pitch * fbdev.height));
+}
+
+/*
+ * Renders a char onto the screen specified by `scr`.
+ *
+ * @x,y: In chars
+ */
+static void
+vcons_draw_char(struct vcons_screen *scr, char c, uint32_t x, uint32_t y)
+{
+    uint32_t *fb_ptr;
+    size_t idx;
+    const uint8_t *glyph;
+
+    /* Get a pointer to framebuffer memory */
+    fb_ptr = scr->fbdev_mem;
+
+    /* Get the specific glyph of `c` */
+    glyph = &DEFAULT_FONT_DATA[(int)c*16];
+
+    for (uint32_t cy = 0; cy < FONT_HEIGHT; ++cy) {
+        for (uint32_t cx = 0; cx < FONT_WIDTH; ++cx) {
+            idx = fbdev_get_index(&scr->fbdev, x+FONT_WIDTH-cx, y+cy);
+            fb_ptr[idx] = __TEST(glyph[cy], __BIT(cx)) ? scr->fg : scr->bg;
+        }
+    }
+}
+
+int
+vcons_putch(struct vcons_screen *scr, char c)
+{
+    uint32_t x = PIX_CPY_X(scr);
+    uint32_t y = PIX_CPY_Y(scr);
+
+    if (scr == NULL) {
+        return 1;
+    }
+
+    if (vcons_process_output(scr, c) >= 0) {
+        /* No need to do anything */
+        return 0;
+    }
+
+    /*
+     * Check text bounds
+     *
+     * We must subtract ncols,nrows by FONT_WIDTH,FONT_HEIGHT
+     * as each char is of that width and we need to account for
+     * that.
+     */
+    if (x >= (scr->ncols - FONT_WIDTH)) {
+        /* Wrap to the next row */
+        ++scr->cpy_y, scr->cpy_x = 0;
+        x = PIX_CPY_X(scr), y = PIX_CPY_Y(scr);
+    }
+    if (y >= (scr->nrows - FONT_HEIGHT)) {
+        scr->cpy_y = 0;
+        scr->cpy_x = 0;
+        vcons_clear_scr(scr);
+        x = PIX_CPY_X(scr), y = PIX_CPY_Y(scr);
+    }
+
+    vcons_draw_char(scr, c, x, y);
+    ++scr->cpy_x;
+    return 0;
+}
+
+void
+vcons_attach(struct vcons_screen *scr)
+{
+    scr->fbdev = fbdev_get_front();
+    scr->fbdev_mem = scr->fbdev.mem;
+
+    scr->nrows = scr->fbdev.height;
+    scr->ncols = scr->fbdev.width;
+
+    screen = scr;
+    vcons_clear_scr(scr);
+}
diff --git a/sys/dev/vcons/vcons_io.c b/sys/dev/vcons/vcons_io.c
new file mode 100644
index 0000000..569cce6
--- /dev/null
+++ b/sys/dev/vcons/vcons_io.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <dev/vcons/vcons_io.h>
+#include <dev/vcons/vcons.h>
+#include <sys/cdefs.h>
+#include <sys/ascii.h>
+
+static void
+vcons_expand_tab(struct vcons_screen *scr)
+{
+    for (size_t i = 0; i < VCONS_TAB_WIDTH; ++i) {
+        vcons_putch(scr, ' ');
+    }
+}
+
+/*
+ * This routine tries to process the output `c'.
+ *
+ * Returns < 0 value on failure. Values >= 0
+ * is `c' which may differ from the original.
+ *
+ * This routine also may modify the screen state
+ * if `c' is a control character.
+ */
+int
+vcons_process_output(struct vcons_screen *scr, int c)
+{
+    struct termios termios = scr->termios;
+
+    switch (c) {
+    case ASCII_LF:
+        if (__TEST(termios.c_oflag, OCRNL))
+            scr->cpy_x = 0;
+        scr->cpy_y++;
+        break;
+    case ASCII_CR:
+        scr->cpy_x = 0;
+        break;
+    case ASCII_HT:
+        vcons_expand_tab(scr);
+        break;
+    default:
+        return -1;
+    }
+
+    return c;
+}