[U-Boot] [PATCH v3] efi_loader: console: Correctly report modes

[Alexander Graf <agraf@suse.de>]

On 10/28/2016 10:04 AM, Emmanuel Vadot wrote:
> 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 V3:
>   Valid mode are 0 to EFIMode-1
>   Fix style
>
> Changes in V2:
>   Add mode switch
>   Report only the modes that we support
>
> Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com>
> ---
>   lib/efi_loader/efi_console.c | 84 +++++++++++++++++++++++++++++++++++---------
>   1 file changed, 68 insertions(+), 16 deletions(-)
>
> diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
> index 2e0228c..eabf54f 100644
> --- a/lib/efi_loader/efi_console.c
> +++ b/lib/efi_loader/efi_console.c
> @@ -9,11 +9,38 @@
>   #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_COUT_MODE_2 2
> +#define EFI_MAX_COUT_MODE 3
> +
> +struct cout_mode {
> +	unsigned long columns;
> +	unsigned long rows;
> +	int present;
> +};
> +
> +static struct cout_mode efi_cout_modes[] = {
> +	/* EFI Mode 0 is 80x25 and always present */
> +	{
> +		.columns = 80,
> +		.rows = 25,
> +		.present = 1,
> +	},
> +	/* EFI Mode 1 is always 80x50 */
> +	{
> +		.columns = 80,
> +		.rows = 50,
> +		.present = 0,
> +	},
> +	/* Value are unknown until we query the console */
> +	{
> +		.columns = 0,
> +		.rows = 0,
> +		.present = 0,
> +	},
> +};
> +
>   const efi_guid_t efi_guid_console_control = CONSOLE_CONTROL_GUID;
>   
>   #define cESC '\x1b'
> @@ -56,8 +83,9 @@ 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,
> +	.max_mode = 1,
>   	.mode = 0,
>   	.attribute = 0,
>   	.cursor_column = 0,
> @@ -131,8 +159,10 @@ static efi_status_t EFIAPI efi_cout_output_string(
>   			struct efi_simple_text_output_protocol *this,
>   			const unsigned short *string)
>   {
> +	struct cout_mode *mode;
>   	u16 ch;
>   
> +	mode = &efi_cout_modes[efi_con_mode.mode];
>   	EFI_ENTRY("%p, %p", this, string);
>   	for (;(ch = *string); string++) {
>   		print_unicode_in_utf8(ch);
> @@ -140,13 +170,12 @@ 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 > 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 > mode->rows)
> +			efi_con_mode.cursor_row = mode->rows;
>   	}
>   
>   	return EFI_EXIT(EFI_SUCCESS);
> @@ -191,15 +220,36 @@ 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) {

This is going to be very tedious to read for someone who isn't familiar 
with the return semantics of term_read_reply(). Please put n[x] into 
local col/row variables and use them in all conditionals afterwards.

> +			efi_cout_modes[1].present = 1;
> +			efi_con_mode.max_mode = 2;
> +		}
> +
> +		/*
> +		 * Install our mode as mode 2 if it is different
> +		 * than mode 0 or 1 and set it to the default one

I guess you want to say "set it as the currently selected mode"?

> +		 */
> +		if ((n[2] != 80 && n[1] != 25) || (n[2] != 80 && n[1] != 50)) {
> +			efi_cout_modes[EFI_COUT_MODE_2].columns = n[2];
> +			efi_cout_modes[EFI_COUT_MODE_2].rows = n[1];
> +			efi_cout_modes[EFI_COUT_MODE_2].present = 1;
> +			efi_con_mode.max_mode = EFI_MAX_COUT_MODE;
> +			efi_con_mode.mode = EFI_COUT_MODE_2;
> +		}
>   	}
>   
> +	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 +260,13 @@ 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);

You're dropping the MODE_TEXT check - is that intentional?


Alex

>   
> -	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(