From 50123cd5368602f68b9650890735947eb7ec501e Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Fri, 26 Feb 2021 21:05:42 +0100
Subject: Removed serial driver from userspace

---
 kernel/Makefile         |  1 +
 kernel/drivers/serial.c | 35 +++++++++++++++++++++++++++++++++++
 kernel/inc/serial.h     | 10 ++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 kernel/drivers/serial.c
 create mode 100644 kernel/inc/serial.h

(limited to 'kernel')

diff --git a/kernel/Makefile b/kernel/Makefile
index 5e5b752..9cf18e5 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -3,6 +3,7 @@
 COBJS = main.o \
 	drivers/interrupts.o \
 	drivers/interrupts_asm.o \
+	drivers/serial.o \
 	drivers/keyboard.o \
 	drivers/mouse.o \
 	drivers/pci.o \
diff --git a/kernel/drivers/serial.c b/kernel/drivers/serial.c
new file mode 100644
index 0000000..98108eb
--- /dev/null
+++ b/kernel/drivers/serial.c
@@ -0,0 +1,35 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <cpu.h>
+#include <def.h>
+#include <serial.h>
+#include <str.h>
+
+void serial_install(void)
+{
+	outb(0x3f8 + 1, 0x00);
+	outb(0x3f8 + 3, 0x80);
+	outb(0x3f8 + 0, 0x03);
+	outb(0x3f8 + 1, 0x00);
+	outb(0x3f8 + 3, 0x03);
+	outb(0x3f8 + 2, 0xC7);
+	outb(0x3f8 + 4, 0x0B);
+}
+
+static int is_transmit_empty(void)
+{
+	return inb(0x3f8 + 5) & 0x20;
+}
+
+void serial_put(char ch)
+{
+	while (is_transmit_empty() == 0)
+		;
+	outb(0x3f8, (u8)ch);
+}
+
+void serial_print(const char *data)
+{
+	for (u32 i = 0; i < strlen(data); i++)
+		serial_put(data[i]);
+}
diff --git a/kernel/inc/serial.h b/kernel/inc/serial.h
new file mode 100644
index 0000000..7ca5ac2
--- /dev/null
+++ b/kernel/inc/serial.h
@@ -0,0 +1,10 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#ifndef SERIAL_H
+#define SERIAL_H
+
+void serial_install(void);
+void serial_print(const char *data);
+void serial_put(char ch);
+
+#endif
-- 
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