term: Do not scroll screen when it shouldn't be

stage23/drivers/vga_textmode.h

@@ -13,6 +13,8 @@ void text_set_cursor_pos(int x, int y);
 void text_get_cursor_pos(int *x, int *y);
 void text_set_text_fg(int fg);
 void text_set_text_bg(int bg);
+bool text_scroll_disable(void);
+void text_scroll_enable(void);
 
 void text_double_buffer(bool state);
 void text_double_buffer_flush(void);

stage23/drivers/vga_textmode.s2.c

@@ -37,7 +37,22 @@ static void draw_cursor(void) {
     }
 }
 
+static bool scroll_enabled = true;
+
+bool text_scroll_disable(void) {
+    bool ret = scroll_enabled;
+    scroll_enabled = false;
+    return ret;
+}
+
+void text_scroll_enable(void) {
+    scroll_enabled = true;
+}
+
 static void scroll(void) {
+    if (scroll_enabled == false)
+        return;
+
     // move the text up by one row
     for (size_t i = 0; i <= VIDEO_BOTTOM - VD_COLS; i++) {
         current_buffer[i] = current_buffer[i + VD_COLS];

stage23/lib/gterm.c

@@ -284,7 +284,22 @@ static inline bool compare_char(struct gterm_char *a, struct gterm_char *b) {
     return !(a->c != b->c || a->bg != b->bg || a->fg != b->fg);
 }
 
+static bool scroll_enabled = true;
+
+bool gterm_scroll_disable(void) {
+    bool ret = scroll_enabled;
+    scroll_enabled = false;
+    return ret;
+}
+
+void gterm_scroll_enable(void) {
+    scroll_enabled = true;
+}
+
 static void scroll(void) {
+    if (scroll_enabled == false)
+        return;
+
     clear_cursor();
 
     for (int i = cols; i < rows * cols; i++) {

stage23/lib/gterm.h

@@ -18,6 +18,8 @@ void gterm_set_cursor_pos(int x, int y);
 void gterm_get_cursor_pos(int *x, int *y);
 void gterm_set_text_fg(int fg);
 void gterm_set_text_bg(int bg);
+bool gterm_scroll_disable(void);
+void gterm_scroll_enable(void);
 
 void gterm_double_buffer_flush(void);
 void gterm_double_buffer(bool state);

stage23/lib/term.c

@@ -27,6 +27,8 @@ void term_vbe(int width, int height) {
     get_cursor_pos = gterm_get_cursor_pos;
     set_text_fg    = gterm_set_text_fg;
     set_text_bg    = gterm_set_text_bg;
+    scroll_disable = gterm_scroll_disable;
+    scroll_enable  = gterm_scroll_enable;
 
     term_double_buffer       = gterm_double_buffer;
     term_double_buffer_flush = gterm_double_buffer_flush;

stage23/lib/term.h

@@ -13,6 +13,8 @@ extern void (*set_cursor_pos)(int x, int y);
 extern void (*get_cursor_pos)(int *x, int *y);
 extern void (*set_text_fg)(int fg);
 extern void (*set_text_bg)(int bg);
+extern bool (*scroll_disable)(void);
+extern void (*scroll_enable)(void);
 
 extern void (*term_double_buffer)(bool status);
 extern void (*term_double_buffer_flush)(void);

stage23/lib/term.s2.c

@@ -25,6 +25,8 @@ void (*set_cursor_pos)(int x, int y);
 void (*get_cursor_pos)(int *x, int *y);
 void (*set_text_fg)(int fg);
 void (*set_text_bg)(int bg);
+bool (*scroll_disable)(void);
+void (*scroll_enable)(void);
 
 void (*term_double_buffer)(bool status);
 void (*term_double_buffer_flush)(void);
@@ -45,6 +47,8 @@ void term_textmode(void) {
     get_cursor_pos = text_get_cursor_pos;
     set_text_fg    = text_set_text_fg;
     set_text_bg    = text_set_text_bg;
+    scroll_disable = text_scroll_disable;
+    scroll_enable  = text_scroll_enable;
 
     term_double_buffer       = text_double_buffer;
     term_double_buffer_flush = text_double_buffer_flush;
@@ -215,8 +219,11 @@ static void control_sequence_parse(uint8_t c) {
                     int x, y;
                     get_cursor_pos(&x, &y);
                     set_cursor_pos(0, y);
+                    bool r = scroll_disable();
                     for (int i = 0; i < term_cols; i++)
                         raw_putchar(' ');
+                    if (r)
+                        scroll_enable();
                     set_cursor_pos(x, y);
                     break;
                 }

stage23/menu.c

@@ -606,7 +606,7 @@ refresh:
             term_double_buffer_flush();
             if ((c = pit_sleep_and_quit_on_keypress(1))) {
                 skip_timeout = true;
-                print("\e[2K\r\e[2A");
+                print("\e[2K\r");
                 term_double_buffer_flush();
                 goto timeout_aborted;
             }