From 6065af357329beb6860f9be797a1a9e5cb73b526 Mon Sep 17 00:00:00 2001
From: Toomas Soome <tsoome@FreeBSD.org>
Date: Sun, 30 Dec 2018 09:05:02 +0000
Subject: [PATCH] MFC r341329: loader.efi: fix EFI getchar() for multiple
 consoles

This fix is ported from illumos (issue #9970), the analysis and initial
implementation was done by John Levon.

See also: https://www.illumos.org/issues/9970

Currently, efi_cons_getchar() will wait for a key. While this seems to make
sense, the implementation of getchar() in common/console.c will loop across
getchar() for all consoles without doing ischar() first.

This means that if we've configured multiple consoles, we can't input into
the serial, as getchar() will be sat waiting for input only from efi_console.c

This patch does implement a bit more generic key buffer to support
translation of input keys, and we use generic efi_readkey() to reduce
duplication from calls from getchar() and poll().

Relnotes:	yes
---
 stand/efi/libefi/efi_console.c | 140 ++++++++++++++++++++++++---------
 1 file changed, 103 insertions(+), 37 deletions(-)

diff --git a/stand/efi/libefi/efi_console.c b/stand/efi/libefi/efi_console.c
index c8275030a2a..de1e3a71164 100644
--- a/stand/efi/libefi/efi_console.c
+++ b/stand/efi/libefi/efi_console.c
@@ -51,7 +51,8 @@ void HO(void);
 void end_term(void);
 #endif
 
-static EFI_INPUT_KEY key_cur;
+#define	KEYBUFSZ 10
+static unsigned keybuf[KEYBUFSZ];	/* keybuf for extended codes */
 static int key_pending;
 
 static void efi_cons_probe(struct console *);
@@ -438,55 +439,120 @@ efi_cons_putchar(int c)
 #endif
 }
 
-int
-efi_cons_getchar()
+static int
+keybuf_getchar(void)
 {
-	EFI_INPUT_KEY key;
-	EFI_STATUS status;
-	UINTN junk;
-
-	if (key_pending) {
-		key = key_cur;
-		key_pending = 0;
-	} else {
-		/* Try to read a key stroke. We wait for one if none is pending. */
-		status = conin->ReadKeyStroke(conin, &key);
-		while (status == EFI_NOT_READY) {
-			/* Some EFI implementation (u-boot for example) do not support WaitForKey */
-			if (conin->WaitForKey != NULL)
-				BS->WaitForEvent(1, &conin->WaitForKey, &junk);
-			status = conin->ReadKeyStroke(conin, &key);
+	int i, c = 0;
+
+	for (i = 0; i < KEYBUFSZ; i++) {
+		if (keybuf[i] != 0) {
+			c = keybuf[i];
+			keybuf[i] = 0;
+			break;
 		}
 	}
 
-	switch (key.ScanCode) {
-	case 0x17: /* ESC */
-		return (0x1b);  /* esc */
+	return (c);
+}
+
+static bool
+keybuf_ischar(void)
+{
+	int i;
+
+	for (i = 0; i < KEYBUFSZ; i++) {
+		if (keybuf[i] != 0)
+			return (true);
 	}
+	return (false);
+}
 
-	/* this can return  */
-	return (key.UnicodeChar);
+/*
+ * We are not reading input before keybuf is empty, so we are safe
+ * just to fill keybuf from the beginning.
+ */
+static void
+keybuf_inschar(EFI_INPUT_KEY *key)
+{
+
+	switch (key->ScanCode) {
+	case 0x1: /* UP */
+		keybuf[0] = 0x1b;	/* esc */
+		keybuf[1] = '[';
+		keybuf[2] = 'A';
+		break;
+	case 0x2: /* DOWN */
+		keybuf[0] = 0x1b;	/* esc */
+		keybuf[1] = '[';
+		keybuf[2] = 'B';
+		break;
+	case 0x3: /* RIGHT */
+		keybuf[0] = 0x1b;	/* esc */
+		keybuf[1] = '[';
+		keybuf[2] = 'C';
+		break;
+	case 0x4: /* LEFT */
+		keybuf[0] = 0x1b;	/* esc */
+		keybuf[1] = '[';
+		keybuf[2] = 'D';
+		break;
+	case 0x17:
+		keybuf[0] = 0x1b;	/* esc */
+		break;
+	default:
+		keybuf[0] = key->UnicodeChar;
+		break;
+	}
 }
 
-int
-efi_cons_poll()
+static bool
+efi_readkey(void)
 {
-	EFI_INPUT_KEY key;
 	EFI_STATUS status;
+	EFI_INPUT_KEY key;
 
-	if (conin->WaitForKey == NULL) {
-		if (key_pending)
-			return (1);
-		status = conin->ReadKeyStroke(conin, &key);
-		if (status == EFI_SUCCESS) {
-			key_cur = key;
-			key_pending = 1;
-		}
-		return (key_pending);
+	status = conin->ReadKeyStroke(conin, &key);
+	if (status == EFI_SUCCESS) {
+		keybuf_inschar(&key);
+		return (true);
 	}
+	return (false);
+}
+
+int
+efi_cons_getchar(void)
+{
+	int c;
+
+	if ((c = keybuf_getchar()) != 0)
+		return (c);
+
+	key_pending = 0;
+
+	if (efi_readkey())
+		return (keybuf_getchar());
+
+	return (-1);
+}
+
+int
+efi_cons_poll(void)
+{
+
+	if (keybuf_ischar() || key_pending)
+		return (1);
+
+	/*
+	 * Some EFI implementation (u-boot for example) do not support
+	 * WaitForKey().
+	 * CheckEvent() can clear the signaled state.
+	 */
+	if (conin->WaitForKey == NULL)
+		key_pending = efi_readkey();
+	else
+		key_pending = BS->CheckEvent(conin->WaitForKey) == EFI_SUCCESS;
 
-	/* This can clear the signaled state. */
-	return (BS->CheckEvent(conin->WaitForKey) == EFI_SUCCESS);
+	return (key_pending);
 }
 
 /* Plain direct access to EFI OutputString(). */
-- 
2.45.0