add VT100 'clear screen' escape code

device/terminal/fx9860/text_display.c

@@ -18,7 +18,9 @@ const struct text_display fx9860_text_display = {
 	.flush = &fx9860_tdisp_flush,
 
 	.set_cursor_pos = &fx9860_tdisp_set_cursor_pos,
-	.set_cursor = &fx9860_tdisp_set_cursor
+	.set_cursor = &fx9860_tdisp_set_cursor,
+
+	.clear = &fx9860_tdisp_clear
 };
 
 
@@ -115,3 +117,8 @@ void fx9860_tdisp_set_cursor_pos(struct tdisp_data *disp, size_t posx,
 void fx9860_tdisp_set_cursor(struct tdisp_data *disp, enum text_cursor curs) {
 	disp->cursor = curs;
 }
+
+
+void fx9860_tdisp_clear(struct tdisp_data *disp) {
+	memset(disp->vram, disp->back ? 0xFF : 0x00, 1024);
+}

device/terminal/fx9860/text_display.h

@@ -37,5 +37,6 @@ void fx9860_tdisp_set_cursor_pos(struct tdisp_data *disp, size_t posx,
 
 void fx9860_tdisp_set_cursor(struct tdisp_data *disp, enum text_cursor curs);
 
+void fx9860_tdisp_clear(struct tdisp_data *disp);
 
 #endif //_DEVICE_TERMINAL_FX9860_TEXT_DISPLAY_H

device/terminal/text_display.h

@@ -79,6 +79,14 @@ struct text_display {
 	 * Set cursor type, if supported.
 	 */
 	void (*set_cursor)(struct tdisp_data *disp, enum text_cursor curs);
+
+
+	/**
+	 * Clear the whole screen (using the current background color).
+	 * TODO should be more generic, to allow erasing of a given part
+	 * of the screen.
+	 */
+	void (*clear)(struct tdisp_data *disp);
 };
 
 

device/terminal/virtual_term.c

@@ -304,7 +304,15 @@ static int vt_parse_escape_code(struct vt_instance *term, char str_char) {
 		break;
 	case 'J':
 		// TODO Erase the screen down to the bottom from the current line. If an argument is given and == 1, erase up to the top instead.
-		// If an argument is given and == 2, clear the whole screen with the background color and go to cursor home.			
+		if(term->esc_state.arguments_index >= 0 
+				&& term->esc_state.arguments[0] == 2)
+		{
+			// If an argument is given and == 2, clear the whole screen with the
+			// background color and go to cursor home.
+			_tdisp->clear(& term->disp);
+			vt_move_cursor(term, 0, 0);
+			vt_delay_flush();
+		}
 		break;
 	case 'p':
 		// TODO Bind a string to a keyboard key
@@ -348,7 +356,6 @@ static void vt_read_escape_code(struct vt_instance *term, char str_char) {
 				term->esc_state.arguments_index++;
 				// check if there are too much arguments for our simple parser
 				if(term->esc_state.arguments_index == VT100_MAX_INTARGS) {
-					vt_clear_escape_code(term);
 					newstate = VT100_STATE_NONE;
 				}
 			} else {
@@ -368,6 +375,8 @@ static void vt_read_escape_code(struct vt_instance *term, char str_char) {
 		break;
 	}
 
+	if(newstate == VT100_STATE_NONE)
+		vt_clear_escape_code(term);
 	term->esc_state.discovery_state = newstate;
 }