Add cursor module.

src/cursor.c

@@ -0,0 +1,26 @@
+#include "cursor.h"
+
+#include "io.h"
+
+void cursor_setRaw(uint16_t address) {
+    io_out(0xA0, 14);
+    io_out(0xA1, (address >> 8) & 0xff);
+    io_out(0xA0, 15);
+    io_out(0xA1, address & 0xff);
+}
+
+void cursor_setXY(uint8_t x, uint8_t y) {
+    cursor_setRaw((uint16_t)y * 80 + x);
+}
+
+void cursor_setStartRaster(uint8_t start) {
+    start &= 0x1f;
+    io_out(0xA0, 10);
+    io_out(0xA1, start);
+}
+
+void cursor_setEndRaster(uint8_t end) {
+    end &= 0x1f;
+    io_out(0xA0, 11);
+    io_out(0xA1, end);
+}

src/cursor.h

@@ -0,0 +1,14 @@
+#ifndef CEDA_CURSOR_H
+#define CEDA_CURSOR_H
+
+#include <stdint.h>
+
+void cursor_setRaw(uint16_t address);
+
+void cursor_setXY(uint8_t x, uint8_t y);
+
+void cursor_setStartRaster(uint8_t start);
+
+void cursor_setEndRaster(uint8_t end);
+
+#endif