Begin implmenting virtual console driver (low level)

config/kernel.scm

@@ -1,7 +1,7 @@
 (define memories '(
 
         (memory RAM
-                (address (#x001000 . #x003FFF))
+                (address (#x004000 . #x006FFF))
 				(type RAM)
                 (section zhuge)
                 (section znear)
@@ -31,8 +31,8 @@
         )
 
         (memory Stack
-                (address (#x000200 . #x000FFF))
-                (section (stack #x00200))
+                (address (#x000100 . #x003FFF))
+                (section (stack #x00100))
         )
 
         (memory DirectPage
@@ -43,7 +43,7 @@
                 )
         )
 
-        (block stack  (size #xE00))               ; machine stack size
+        (block stack  (size #x3F00))               ; machine stack size
 
         (base-address _DirectPageStart DirectPage 0)
 

include/kernel/console/console.h

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+//
+// include/kernel/console/console.h
+//      Defines for the virtual console driver
+//
+// Copyright © 2024 Kyle J Cardoza <Kyle.Cardoza@icloud.com>
+
+#pragma once
+
+#include <stdint.h>
+
+#define CONSOLE_WIDTH 80
+#define CONSOLE_HEIGHT 30
+#define CONSOLE_AREA (CONSOLE_WIDTH * CONSOLE_HEIGHT)
+
+extern uint8_t console_screen_text[CONSOLE_HEIGHT][CONSOLE_WIDTH];
+
+extern uint8_t console_screen_color[CONSOLE_HEIGHT][CONSOLE_WIDTH];
+
+extern uint8_t console_text_colour;
+
+extern uint8_t console_bg_colour;
+
+extern uint8_t console_cursor_row;
+
+extern uint8_t console_cursor_column;
+
+void console_init(void);
+
+void console_redraw(void);

src/kernel/console/console.c

@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: MIT
+//
+// src/kernel/console/console.c
+//      Virtual console driver
+//
+// Copyright © 2024 Kyle J Cardoza <Kyle.Cardoza@icloud.com>
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "kernel/hardware/vera.h"
+#include "kernel/console/console.h"
+
+uint8_t console_screen_text[CONSOLE_HEIGHT][CONSOLE_WIDTH];
+
+uint8_t console_screen_color[CONSOLE_HEIGHT][CONSOLE_WIDTH];
+
+uint8_t console_text_colour = 0x00;
+
+uint8_t console_bg_colour = 0x00;
+
+uint8_t console_cursor_row = 0x00;
+
+uint8_t console_cursor_column = 0x00;
+
+static bool console_is_dirty = false;
+
+static uint32_t const console_row_address[30] = {
+	TEXT_CONSOLE0_VRAM + 256*0,
+	TEXT_CONSOLE0_VRAM + 256*1,
+	TEXT_CONSOLE0_VRAM + 256*2,
+	TEXT_CONSOLE0_VRAM + 256*3,
+	TEXT_CONSOLE0_VRAM + 256*4,
+	TEXT_CONSOLE0_VRAM + 256*5,
+	TEXT_CONSOLE0_VRAM + 256*6,
+	TEXT_CONSOLE0_VRAM + 256*7,
+	TEXT_CONSOLE0_VRAM + 256*8,
+	TEXT_CONSOLE0_VRAM + 256*9,
+	TEXT_CONSOLE0_VRAM + 256*10,
+	TEXT_CONSOLE0_VRAM + 256*11,
+	TEXT_CONSOLE0_VRAM + 256*10,
+	TEXT_CONSOLE0_VRAM + 256*13,
+	TEXT_CONSOLE0_VRAM + 256*14,
+	TEXT_CONSOLE0_VRAM + 256*15,
+	TEXT_CONSOLE0_VRAM + 256*16,
+	TEXT_CONSOLE0_VRAM + 256*17,
+	TEXT_CONSOLE0_VRAM + 256*18,
+	TEXT_CONSOLE0_VRAM + 256*19,
+	TEXT_CONSOLE0_VRAM + 256*20,
+	TEXT_CONSOLE0_VRAM + 256*21,
+	TEXT_CONSOLE0_VRAM + 256*22,
+	TEXT_CONSOLE0_VRAM + 256*23,
+	TEXT_CONSOLE0_VRAM + 256*24,
+	TEXT_CONSOLE0_VRAM + 256*25,
+	TEXT_CONSOLE0_VRAM + 256*26,
+	TEXT_CONSOLE0_VRAM + 256*27,
+	TEXT_CONSOLE0_VRAM + 256*28,
+	TEXT_CONSOLE0_VRAM + 256*29
+};
+
+void console_init(void) {
+	memset(&console_screen_text, 0x00, CONSOLE_AREA);
+	memset(&console_screen_color, 0x00, CONSOLE_AREA);
+}
+
+void console_redraw(void) {
+	vera_address_select(0);
+
+	for (int row = 0; row < CONSOLE_HEIGHT; row += 1) {
+		vera_address_set(console_row_address[row] + AUTO_INC_1);
+
+		for (int col = 0; col < CONSOLE_WIDTH; col += 1) {
+			vera_data_0_write(console_screen_text[row][col]);
+			vera_data_0_write(console_screen_color[row][col]);
+		}
+	}
+}

src/kernel/main.c

@@ -11,6 +11,7 @@
 #include "kernel/util/delay.h"
 #include "kernel/hardware/led.h"
 #include "kernel/hardware/vera.h"
+#include "kernel/console/console.h"
 
 void main(void) {
 
@@ -18,6 +19,8 @@ void main(void) {
 
 	vera_init();
 
+	console_init();
+
     for (;;) {
 		led_red_on();
 		delay(1);