kernel: cons: Add ANSI cursor pos reset sequence

- Add support for the "\033[H" ANSI escape sequence to
  reset the cursor to the 'home' position

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

4 files changed, 20 insertions, 0 deletions

diff --git a/sys/dev/cons/cons.c b/sys/dev/cons/cons.c
index 88f394b..ce2b154 100644
--- a/sys/dev/cons/cons.c
+++ b/sys/dev/cons/cons.c
@@ -422,6 +422,17 @@ cons_update_color(struct cons_screen *scr, uint32_t fg, uint32_t bg)
     scr->bg = bg;
 }
 
+void
+cons_reset_cursor(struct cons_screen *scr)
+{
+    HIDE_CURSOR(scr);
+    scr->ch_col = 0;
+    scr->ch_row = 0;
+    scr->curs_col = 0;
+    scr->curs_row = 0;
+    SHOW_CURSOR(scr);
+}
+
 /*
  * Put a character on the screen.
  *
diff --git a/sys/dev/cons/cons_ansi.c b/sys/dev/cons/cons_ansi.c
index a91f1d3..4403f9c 100644
--- a/sys/dev/cons/cons_ansi.c
+++ b/sys/dev/cons/cons_ansi.c
@@ -88,6 +88,13 @@ ansi_feed(struct ansi_state *statep, char c)
         statep->csi = 2;
         statep->prev = c;
         return c;
+    case 2:
+        if (c == 'H') {
+            cons_reset_cursor(&g_root_scr);
+            ansi_reset(statep);
+            return ANSI_UPDATE_CURSOR;
+        }
+        break;
     }
 
     if (!statep->set_fg && !statep->set_bg) {
diff --git a/sys/include/dev/cons/ansi.h b/sys/include/dev/cons/ansi.h
index 98d7618..f166458 100644
--- a/sys/include/dev/cons/ansi.h
+++ b/sys/include/dev/cons/ansi.h
@@ -46,6 +46,7 @@
 
 /* ANSI_FEED update codes */
 #define ANSI_UPDATE_COLOR  -1
+#define ANSI_UPDATE_CURSOR -2
 
 /*
  * ANSI parser state machine.
diff --git a/sys/include/dev/cons/cons.h b/sys/include/dev/cons/cons.h
index 13153b2..9868493 100644
--- a/sys/include/dev/cons/cons.h
+++ b/sys/include/dev/cons/cons.h
@@ -68,6 +68,7 @@ void cons_init(void);
 void cons_expose(void);
 void cons_update_color(struct cons_screen *scr, uint32_t fg, uint32_t bg);
 void cons_reset_color(struct cons_screen *scr);
+void cons_reset_cursor(struct cons_screen *scr);
 int cons_putch(struct cons_screen *scr, char c);
 int cons_putstr(struct cons_screen *scr, const char *s, size_t len);