From 56bef77cceccfdf790c0bf030634514d9e3e3c71 Mon Sep 17 00:00:00 2001
From: Ali Mashtizadeh <mashti@uwaterloo.ca>
Date: Fri, 22 Sep 2023 21:07:27 -0400
Subject: [PATCH] Fix backspace emulation in the serial console and in fgets()

---
 lib/libc/file.c       | 5 +++++
 sys/dev/x86/sercons.c | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/lib/libc/file.c b/lib/libc/file.c
index e728cf4..2347a22 100644
--- a/lib/libc/file.c
+++ b/lib/libc/file.c
@@ -171,6 +171,11 @@ fgets(char *str, int size, FILE *fh)
 	int ch = fgetc(fh);
 	if (ch == EOF)
 	    return NULL;
+	if (ch == '\b') {
+	    if (i > 0)
+		i -= 2;
+	    continue;
+	}
 	str[i] = (char)ch;
 	if (ch == '\n') {
 	    str[i + 1] = '\0';
diff --git a/sys/dev/x86/sercons.c b/sys/dev/x86/sercons.c
index 6536e6d..6616b98 100644
--- a/sys/dev/x86/sercons.c
+++ b/sys/dev/x86/sercons.c
@@ -91,6 +91,12 @@ void Serial_Putc(char ch)
 	// Timeout!
     }
     outb(base + UART_OFFSET_DATA, ch);
+
+    if (ch == '\b') {
+	Serial_Putc(0x1B);
+	Serial_Putc('[');
+	Serial_Putc('P');
+    }
 }
 
 void Serial_Puts(const char *str)