[SLOF] [PATCH 3/4] bootmenu: Implement keyboard handling and boot menu selection

[Thomas Huth]

On 05.06.2017 07:42, Nikunj A Dadhania wrote:
> Thomas Huth <thuth at redhat.com> writes:
> 
>> Wait for a key and return the selected boot device on the Forth stack.
>>
>> Signed-off-by: Thomas Huth <thuth at redhat.com>
>> ---
>>  lib/libbootmenu/bootmenu.c    | 74 +++++++++++++++++++++++++++++++++++++++++++
>>  lib/libbootmenu/bootmenu.code |  2 +-
>>  2 files changed, 75 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/libbootmenu/bootmenu.c b/lib/libbootmenu/bootmenu.c
>> index 649e518..979cdc4 100644
>> --- a/lib/libbootmenu/bootmenu.c
>> +++ b/lib/libbootmenu/bootmenu.c
>> @@ -12,10 +12,12 @@
>>   *     Thomas Huth, Red Hat Inc. - initial implementation
>>   *****************************************************************************/
>>
>> +#include <stdbool.h>
>>  #include <string.h>
>>  #include <stdio.h>
>>  #include <stdlib.h>
>>  #include <paflof.h>
>> +#include <helpers.h>
>>  #include "bootmenu.h"
>>
>>  #define MAX_DEVS 36        /* Enough for 10 digits + 26 letters */
>> @@ -93,15 +95,87 @@ static void bootmenu_show_devs(void)
>>  	}
>>  }
>>
>> +static bool has_key(void)
>> +{
>> +	forth_eval("key?");
>> +	return forth_pop();
>> +}
>> +
>> +static char get_key(void)
>> +{
>> +	forth_eval("key");
>> +	return forth_pop();
>> +}
>> +
>> +/* Flush pending key presses */
>> +static void flush_keys(void)
>> +{
>> +	uint32_t start;
>> +
>> +	start = SLOF_GetTimer();
>> +	while (SLOF_GetTimer() - start < 10) {
>> +		if (has_key()) {
>> +			get_key();
>> +			start = SLOF_GetTimer();
>> +		}
>> +	}
>> +}
>> +
>> +static int bootmenu_get_selection(void)
>> +{
>> +	char key = 0;
>> +	int sel;
>> +
>> +	do {
>> +		sel = -1;
>> +		if (!has_key())
>> +			continue;
>> +		key = get_key();
>> +		switch (key) {
>> +		case '0':
>> +			return -1;
>> +		case '1' ... '9':
>> +			sel = key - '1';
>> +			break;
>> +		case 'a' ... 'z':
>> +			sel = key - 'a' + 9;
>> +			break;
>> +		case 'A' ... 'Z':
>> +			sel = key - 'A' + 9;
>> +			break;
> 
> With this we can have 1-9, a-z and A-Z, 10 + 26 + 26 = 62 selection.
> Though displaying them on one screen is difficult. MAX_DEVS is set to 36
> though.

Right, currently I treat the letters case-insensitive. We could increase
MAX_DEVS to 62 by treating the letters case-sensitive instead ...
question is, do we want that, or are 36 possible boot devices enough
(since 62 hardly fit on a screen anyway, as you noted)?

 Thomas