From 97d36f069d3362cd09b481fba94ee1de01a1f51b Mon Sep 17 00:00:00 2001
From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Sun, 27 Dec 2020 14:47:50 +0100
Subject: [PATCH] efi_loader: escape key handling
Up to now the escape key was not correctly detected in UEFI applications.
We had to hit it twice for a single escape to be recognized.
Use a 10 ms delay to detect if we are dealing with the escape key or an
escape sequence.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
lib/efi_loader/efi_console.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index 011accab78..705109596e 100644
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -14,6 +14,7 @@
#include <env.h>
#include <stdio_dev.h>
#include <video_console.h>
+#include <linux/delay.h>
#define EFI_COUT_MODE_2 2
#define EFI_MAX_COUT_MODE 3
@@ -688,6 +689,17 @@ static efi_status_t efi_cin_read_key(struct efi_key_data *key)
switch (ch) {
case 0x1b:
+ /*
+ * If a second key is received within 10 ms, assume that we are
+ * dealing with an escape sequence. Otherwise consider this the
+ * escape key being hit. 10 ms is long enough to work fine at
+ * 1200 baud and above.
+ */
+ udelay(10000);
+ if (!tstc()) {
+ pressed_key.scan_code = 23;
+ break;
+ }
/*
* Xterm Control Sequences
* https://www.xfree86.org/4.8.0/ctlseqs.html
--
2.39.5