[FREELDR] Add UEFI Console input support. CORE-11954 (#5426)

Co-authored-by: Stanislav Motylkov <x86corez@gmail.com>

boot/freeldr/freeldr/arch/uefi/stubs.c

@@ -55,18 +55,6 @@ UefiPcBeep(VOID)
     /* Not possible on UEFI, for now */
 }
 
-BOOLEAN
-UefiConsKbHit(VOID)
-{
-    return FALSE;
-}
-
-int
-UefiConsGetCh(void)
-{
-    return 0;
-}
-
 VOID
 UefiHwIdle(VOID)
 {

boot/freeldr/freeldr/arch/uefi/ueficon.c

@@ -16,6 +16,9 @@ extern EFI_SYSTEM_TABLE* GlobalSystemTable;
 static unsigned CurrentCursorX = 0;
 static unsigned CurrentCursorY = 0;
 static unsigned CurrentAttr = 0x0f;
+static EFI_INPUT_KEY Key;
+static BOOLEAN ExtendedKey = FALSE;
+static char ExtendedScanCode = 0;
 
 /* FUNCTIONS ******************************************************************/
 
@@ -59,3 +62,82 @@ UefiConsPutChar(int c)
         CurrentCursorY++;
     }
 }
+
+static
+UCHAR
+ConvertToBiosExtValue(UCHAR KeyIn)
+{
+    switch (KeyIn)
+    {
+        case SCAN_UP:
+            return KEY_UP;
+        case SCAN_DOWN:
+            return KEY_DOWN;
+        case SCAN_RIGHT:
+            return KEY_RIGHT;
+        case SCAN_LEFT:
+            return KEY_LEFT;
+        case SCAN_F1:
+            return KEY_F1;
+        case SCAN_F2:
+            return KEY_F2;
+        case SCAN_F3:
+            return KEY_F3;
+        case SCAN_F4:
+            return KEY_F4;
+        case SCAN_F5:
+            return KEY_F5;
+        case SCAN_F6:
+            return KEY_F6;
+        case SCAN_F7:
+            return KEY_F7;
+        case SCAN_F8:
+            return KEY_F8;
+        case SCAN_F9:
+            return KEY_F9;
+        case SCAN_F10:
+            return KEY_F10;
+        case SCAN_ESC:
+            return KEY_ESC;
+        case SCAN_DELETE:
+            return KEY_DELETE;
+    }
+    return 0;
+}
+
+BOOLEAN
+UefiConsKbHit(VOID)
+{
+    return (GlobalSystemTable->ConIn->ReadKeyStroke(GlobalSystemTable->ConIn, &Key) != EFI_NOT_READY);
+}
+
+int
+UefiConsGetCh(VOID)
+{
+    UCHAR KeyOutput = 0;
+
+    /* If an extended key press was detected the last time we were called
+     * then return the scan code of that key. */
+    if (ExtendedKey)
+    {
+        ExtendedKey = FALSE;
+        return ExtendedScanCode;
+    }
+
+    if (Key.UnicodeChar != 0)
+    {
+        KeyOutput = Key.UnicodeChar;
+    }
+    else
+    {
+        ExtendedKey = TRUE;
+        ExtendedScanCode = ConvertToBiosExtValue(Key.ScanCode);
+        KeyOutput = KEY_EXTENDED;
+    }
+
+    /* UEFI will stack input requests, we have to clear it */
+    Key.UnicodeChar = 0;
+    Key.ScanCode = 0;
+    GlobalSystemTable->ConIn->Reset(GlobalSystemTable->ConIn, FALSE);
+    return KeyOutput;
+}