efi/console: Add grub_console_read_key_stroke() helper function

This is a preparatory patch for adding getkeystatus() support to the
EFI console driver.

We can get modifier status through the simple_text_input read_key_stroke()
method, but if a non-modifier key is (also) pressed the read_key_stroke()
call will consume that key from the firmware's queue.

The new grub_console_read_key_stroke() helper buffers upto 1 key-stroke.
If it has a non-modifier key buffered, it will return that one, if its
buffer is empty, it will fills its buffer by getting a new key-stroke.

If called with consume=1 it will empty its buffer after copying the
key-data to the callers buffer, this is how getkey() will use it.

If called with consume=0 it will keep the last key-stroke buffered, this
is how getkeystatus() will call it. This means that if a non-modifier
key gets pressed, repeated getkeystatus() calls will return the modifiers
of that key-press until it is consumed by a getkey() call.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Hans de Goede 2020-04-15 12:26:19 +02:00 committed by Daniel Kiper
parent 5bcdf67642
commit 8bab36af60

View file

@ -193,27 +193,57 @@ grub_console_getkey_con (struct grub_term_input *term __attribute__ ((unused)))
return grub_efi_translate_key(key);
}
/*
* When more then just modifiers are pressed, our getkeystatus() consumes a
* press from the queue, this function buffers the press for the regular
* getkey() so that it does not get lost.
*/
static grub_err_t
grub_console_read_key_stroke (
grub_efi_simple_text_input_ex_interface_t *text_input,
grub_efi_key_data_t *key_data_ret, int *key_ret,
int consume)
{
static grub_efi_key_data_t key_data;
grub_efi_status_t status;
int key;
if (!text_input)
return GRUB_ERR_EOF;
key = grub_efi_translate_key (key_data.key);
if (key == GRUB_TERM_NO_KEY) {
status = efi_call_2 (text_input->read_key_stroke, text_input, &key_data);
if (status != GRUB_EFI_SUCCESS)
return GRUB_ERR_EOF;
key = grub_efi_translate_key (key_data.key);
}
*key_data_ret = key_data;
*key_ret = key;
if (consume) {
key_data.key.scan_code = 0;
key_data.key.unicode_char = 0;
}
return GRUB_ERR_NONE;
}
static int
grub_console_getkey_ex (struct grub_term_input *term)
{
grub_efi_key_data_t key_data;
grub_efi_status_t status;
grub_efi_uint32_t kss;
grub_err_t err;
int key = -1;
grub_efi_simple_text_input_ex_interface_t *text_input = term->data;
status = efi_call_2 (text_input->read_key_stroke, text_input, &key_data);
if (status != GRUB_EFI_SUCCESS)
err = grub_console_read_key_stroke (term->data, &key_data, &key, 1);
if (err != GRUB_ERR_NONE || key == GRUB_TERM_NO_KEY)
return GRUB_TERM_NO_KEY;
kss = key_data.key_state.key_shift_state;
key = grub_efi_translate_key(key_data.key);
if (key == GRUB_TERM_NO_KEY)
return GRUB_TERM_NO_KEY;
if (kss & GRUB_EFI_SHIFT_STATE_VALID)
{
if ((kss & GRUB_EFI_LEFT_SHIFT_PRESSED