From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Hans de Goede <hdegoede@redhat.com>

Date: Wed, 6 Jun 2018 15:54:44 +0200

Subject: [PATCH] EFI: console: Add grub_console_read_key_stroke() helper

 function

This is a preparation patch for adding getkeystatus() support to the

EFI console terminal input 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>

---

 grub-core/term/efi/console.c | 51 ++++++++++++++++++++++++++++++++++----------

 1 file changed, 40 insertions(+), 11 deletions(-)

diff --git a/grub-core/term/efi/console.c b/grub-core/term/efi/console.c

index 051633d71e9..3d36c5c701b 100644

--- a/grub-core/term/efi/console.c

+++ b/grub-core/term/efi/console.c

@@ -157,27 +157,56 @@ 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 int

+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 0;

+}

+

 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;

   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)

+  if (grub_console_read_key_stroke (term->data, &key_data, &key, 1) ||

+      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