VbCheckDisplayKey: Remove easter egg support

We haven't used the easter egg screen since Mario. Time to get rid of
that code.

BRANCH=None
BUG=None
TEST=Booted Kevin.

Change-Id: I8f403f296ebb2a3d14ba6a70f12cd13a58e67b64
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1548303
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
diff --git a/firmware/lib/include/utility.h b/firmware/lib/include/utility.h
index ca9bcd7..e887249 100644
--- a/firmware/lib/include/utility.h
+++ b/firmware/lib/include/utility.h
@@ -22,13 +22,6 @@
 #define VbAssert(expr)
 #endif
 
-/* Optional, up to the BIOS */
-#ifdef VBOOT_EASTER_EGG
-#define VBEASTEREGG VbExEasterEgg()
-#else
-#define VBEASTEREGG 0
-#endif
-
 /*
  * Combine [msw] and [lsw] uint16s to a uint32_t with its [msw] and [lsw]
  * forming the most and least signficant 16-bit words.
diff --git a/firmware/lib/vboot_display.c b/firmware/lib/vboot_display.c
index e735946..c4b4f87 100644
--- a/firmware/lib/vboot_display.c
+++ b/firmware/lib/vboot_display.c
@@ -399,22 +399,11 @@
 	return VbExDisplayDebugInfo(buf, 1);
 }
 
-#define MAGIC_WORD_LEN 5
-#define MAGIC_WORD "xyzzy"
-static uint8_t MagicBuffer[MAGIC_WORD_LEN];
-
 VbError_t VbCheckDisplayKey(struct vb2_context *ctx, uint32_t key,
 			    const VbScreenData *data)
 {
 	uint32_t loc = 0;
 	uint32_t count = 0;
-	int i;
-
-	/* Update key buffer */
-	for(i = 1; i < MAGIC_WORD_LEN; i++)
-		MagicBuffer[i - 1] = MagicBuffer[i];
-	/* Save as lower-case ASCII */
-	MagicBuffer[MAGIC_WORD_LEN - 1] = (key | 0x20) & 0xFF;
 
 	switch (key) {
 	case '\t':
@@ -457,11 +446,5 @@
 		return VbDisplayScreen(ctx, disp_current_screen, 1, data);
 	}
 
-	if (0 == memcmp(MagicBuffer, MAGIC_WORD, MAGIC_WORD_LEN)) {
-		if (VBEASTEREGG)
-			(void)VbDisplayScreen(ctx, disp_current_screen, 1,
-					      NULL);
-	}
-
 	return VBERROR_SUCCESS;
 }