[U-Boot] [PATCH v2] efi_loader: console: Correctly report modes

[Emmanuel Vadot]

Add support for EFI console modes.
Mode 0 is always 80x25 and present by EFI specification.
Mode 1 is always 80x50 and not mandatory.
Mode 2 and above is freely usable.

If the terminal can handle mode 1, we mark it as supported.
If the terminal size is greater than mode 0 and different than mode 1,
we install it as mode 2.

Modes can be switch with cout_set_mode.

Changes in V2:
 Add mode switch
 Report only the modes that we support

Signed-off-by: Emmanuel Vadot <manu at bidouilliste.com>
---
 lib/efi_loader/efi_console.c | 78 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 64 insertions(+), 14 deletions(-)

diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index 2e0228c..f4adc9e 100644
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -9,11 +9,41 @@
 #include <common.h>
 #include <efi_loader.h>
 
-/* If we can't determine the console size, default to 80x24 */
-static int console_columns = 80;
-static int console_rows = 24;
 static bool console_size_queried;
 
+#define EFI_MAX_COUT_MODE 2
+
+struct cout_mode {
+	unsigned long number;
+	unsigned long columns;
+	unsigned long rows;
+	int present;
+};
+
+static struct cout_mode efi_cout_modes[] = {
+	/* EFI Mode 0 is 80x25 and always present */
+	{
+		.number = 0,
+		.columns = 80,
+		.rows = 25,
+		.present = 1,
+	},
+	/* EFI Mode 1 is always 80x50 */
+	{
+		.number = 1,
+		.columns = 80,
+		.rows = 50,
+		.present = 0,
+	},
+	/* Value are unknown until we query the console */
+	{
+		.number = 2,
+		.columns = 0,
+		.rows = 0,
+		.present = 0,
+	},
+};
+
 const efi_guid_t efi_guid_console_control = CONSOLE_CONTROL_GUID;
 
 #define cESC '\x1b'
@@ -56,6 +86,7 @@ const struct efi_console_control_protocol efi_console_control = {
 	.lock_std_in = efi_cin_lock_std_in,
 };
 
+/* Default to mode 0 */
 static struct simple_text_output_mode efi_con_mode = {
 	.max_mode = 0,
 	.mode = 0,
@@ -140,12 +171,12 @@ static efi_status_t EFIAPI efi_cout_output_string(
 		if (ch == '\n') {
 			efi_con_mode.cursor_column = 1;
 			efi_con_mode.cursor_row++;
-		} else if (efi_con_mode.cursor_column > console_columns) {
+		} else if (efi_con_mode.cursor_column > efi_cout_modes[efi_con_mode.mode].columns) {
 			efi_con_mode.cursor_column = 1;
 			efi_con_mode.cursor_row++;
 		}
-		if (efi_con_mode.cursor_row > console_rows) {
-			efi_con_mode.cursor_row = console_rows;
+		if (efi_con_mode.cursor_row > efi_cout_modes[efi_con_mode.mode].rows) {
+			efi_con_mode.cursor_row = efi_cout_modes[efi_con_mode.mode].rows;
 		}
 	}
 
@@ -191,15 +222,32 @@ static efi_status_t EFIAPI efi_cout_query_mode(
 			goto out;
 		}
 
-		console_columns = n[2];
-		console_rows = n[1];
+		/* Test if we can have Mode 1 */
+		if (n[2] >= 80 && n[1] >= 50) {
+			efi_cout_modes[1].present = 1;
+			efi_con_mode.max_mode = 1;
+		}
+
+		/* Install our mode as mode 2 if it is different than mode 0 or 1 and set it to the default one */
+		if ((n[2] != 80 && n[1] != 25) || (n[2] != 80 && n[1] != 50)) {
+			efi_cout_modes[EFI_MAX_COUT_MODE].columns = n[2];
+			efi_cout_modes[EFI_MAX_COUT_MODE].rows = n[1];
+			efi_cout_modes[EFI_MAX_COUT_MODE].present = 1;
+			efi_con_mode.max_mode = EFI_MAX_COUT_MODE;
+			efi_con_mode.mode = EFI_MAX_COUT_MODE;
+		}
 	}
 
+	if (mode_number > efi_con_mode.max_mode)
+		return EFI_EXIT(EFI_UNSUPPORTED);
+	if (efi_cout_modes[mode_number].present != 1)
+		return EFI_EXIT(EFI_UNSUPPORTED);
+
 out:
 	if (columns)
-		*columns = console_columns;
+		*columns = efi_cout_modes[mode_number].columns;
 	if (rows)
-		*rows = console_rows;
+		*rows = efi_cout_modes[mode_number].rows;
 
 	return EFI_EXIT(EFI_SUCCESS);
 }
@@ -210,11 +258,13 @@ static efi_status_t EFIAPI efi_cout_set_mode(
 {
 	EFI_ENTRY("%p, %ld", this, mode_number);
 
-	/* We only support text output for now */
-	if (mode_number == EFI_CONSOLE_MODE_TEXT)
-		return EFI_EXIT(EFI_SUCCESS);
 
-	return EFI_EXIT(EFI_UNSUPPORTED);
+	if (mode_number > efi_con_mode.max_mode)
+		return EFI_EXIT(EFI_UNSUPPORTED);
+
+	efi_con_mode.mode = mode_number;
+
+	return EFI_EXIT(EFI_SUCCESS);
 }
 
 static efi_status_t EFIAPI efi_cout_set_attribute(
-- 
2.9.2