efi, ansi: Improve console handling even further (e.g. scrolling support)

There were quite a few trivial bugs in the EFI console code, such as
mixing up column and row arguments and implementing functions with
different semantics when compared with the BIOS code.

With these changes console output now looks the same as the BIOS
version, with output scrolling down the screen instead of overwriting
existing text at the top whenever it incremented past the last row.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>

2 files changed, 30 insertions, 30 deletions

diff --git a/com32/lib/sys/ansi.c b/com32/lib/sys/ansi.c
index db47ea46..f73c03e2 100644
--- a/com32/lib/sys/ansi.c
+++ b/com32/lib/sys/ansi.c
@@ -438,14 +438,6 @@ void __ansi_putchar(const struct term_info *ti, uint8_t ch)
 	op->scroll_up(st);
     }
 
-    /*
-     * Testing on EFI shows that from (rows-1)th line newline does not
-     * advance anymore.  All further output is always on the same
-     * (rows-1)th line.  Resetting the row to 0 does work.
-     */
-    if (xy.y == rows-1)
-	xy.y = 0;
-
     /* Update cursor position */
     op->set_cursor(xy.x, xy.y, st->cursor);
     st->xy = xy;
diff --git a/efi/main.c b/efi/main.c
index 379b475c..7c1887c2 100644
--- a/efi/main.c
+++ b/efi/main.c
@@ -108,16 +108,6 @@ uint8_t KeepPXE;
 volatile uint32_t __ms_timer = 0xdeadbeef;
 volatile uint32_t __jiffies = 0;
 
-static UINTN cursor_x, cursor_y;
-static void efi_erase(const struct term_state *st,
-		       int x0, int y0, int x1, int y1)
-{
-	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
-	cursor_x = cursor_y = 0;
-	/* Really clear the screen */
-	uefi_call_wrapper(out->ClearScreen, 1, out);
-}
-
 static void efi_write_char(uint8_t ch, uint8_t attribute)
 {
 	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
@@ -131,45 +121,63 @@ static void efi_write_char(uint8_t ch, uint8_t attribute)
 static void efi_showcursor(const struct term_state *st)
 {
 	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
-	uefi_call_wrapper(out->SetCursorPosition, 3, out, cursor_x, cursor_y);
+
+	uefi_call_wrapper(out->EnableCursor, 2, out, true);
 }
 
 static void efi_set_cursor(int x, int y, bool visible)
 {
 	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
 
-	if (visible) {
-		uefi_call_wrapper(out->SetCursorPosition, 3, out, x, y);
-		cursor_x = x;
-		cursor_y = y;
-	} else
-		uefi_call_wrapper(out->EnableCursor, 2, out, false);
+	uefi_call_wrapper(out->SetCursorPosition, 3, out, x, y);
 }
 
 static void efi_scroll_up(uint8_t cols, uint8_t rows, uint8_t attribute)
 {
+	efi_write_char('\n', 0);
+	efi_write_char('\r', 0);
 }
 
-
 static void efi_get_mode(int *cols, int *rows)
 {
 	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
 	UINTN c, r;
 
-	/* XXX: Assume we're at 80x25 for now (mode 0) */
-	uefi_call_wrapper(out->QueryMode, 4, out, 0, &c, &r);
+	uefi_call_wrapper(out->QueryMode, 4, out, out->Mode->Mode, &c, &r);
 	*rows = r;
 	*cols = c;
 }
 
+static void efi_erase(const struct term_state *st,
+		       int x0, int y0, int x1, int y1)
+{
+	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
+	int cols, rows;
+
+	efi_get_mode(&cols, &rows);
+
+	/*
+	 * The BIOS version of this function has the ability to erase
+	 * parts or all of the screen - the UEFI console doesn't
+	 * support this so we just set the cursor position unless
+	 * we're clearing the whole screen.
+	 */
+	if (!x0 && !y0 && x1 == (rows - 1) && y1 == (cols - 1)) {
+		/* Really clear the screen */
+		uefi_call_wrapper(out->ClearScreen, 1, out);
+	} else
+		uefi_call_wrapper(out->SetCursorPosition, 3, out, y0, x0);
+}
+
 static void efi_set_mode(uint16_t mode)
 {
 }
 
 static void efi_get_cursor(int *x, int *y)
 {
-	*x = cursor_x;
-	*y = cursor_y;
+	SIMPLE_TEXT_OUTPUT_INTERFACE *out = ST->ConOut;
+	*x = out->Mode->CursorColumn;
+	*y = out->Mode->CursorRow;
 }
 
 struct output_ops efi_ops = {