[U-Boot] [PATCH 1/2] efi_loader: cursor positioning
Heinrich Schuchardt
xypron.glpk at gmx.de
Thu Sep 5 08:06:03 UTC 2019
When backspacing in column 0 do no set the column index to ULONG_MAX.
Ensure that the row number is not set to ULONG_MAX even if the row count is
advertised as 0.
Ignore control characters other the 0x08, 0x0a, 0x0d when updating the
column.
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
lib/efi_loader/efi_console.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index d4765afb98..d5222c46b4 100644
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -156,13 +156,14 @@ static efi_status_t EFIAPI efi_cout_output_string(
* Update the cursor position.
*
* The UEFI spec provides advance rules for U+0000, U+0008, U+000A,
- * and U000D. All other characters, including control characters
- * U+0007 (BEL) and U+0009 (TAB), have to increase the column by one.
+ * and U000D. All other control characters are ignored. Any non-control
+ * character increase the column by one.
*/
for (p = string; *p; ++p) {
switch (*p) {
case '\b': /* U+0008, backspace */
- con->cursor_column = max(0, con->cursor_column - 1);
+ if (con->cursor_column)
+ con->cursor_column--;
break;
case '\n': /* U+000A, newline */
con->cursor_column = 0;
@@ -178,13 +179,16 @@ static efi_status_t EFIAPI efi_cout_output_string(
*/
break;
default:
- con->cursor_column++;
+ if (*p > 0x1f)
+ con->cursor_column++;
break;
}
if (con->cursor_column >= mode->columns) {
con->cursor_column = 0;
con->cursor_row++;
}
+ if (con->cursor_row >= mode->rows && con->cursor_row)
+ con->cursor_row--;
con->cursor_row = min(con->cursor_row, (s32)mode->rows - 1);
}
--
2.23.0.rc1
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