kernel/include/kernel/Process.h

@@ -118,6 +118,8 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_mmap(const sys_mmap_t*);
 		BAN::ErrorOr<long> sys_munmap(void* addr, size_t len);
 
+		BAN::ErrorOr<long> sys_tty_ctrl(int fildes, int command, int flags);
+
 		BAN::ErrorOr<long> sys_signal(int, void (*)(int));
 		BAN::ErrorOr<long> sys_raise(int signal);
 		static BAN::ErrorOr<long> sys_kill(pid_t pid, int signal);

kernel/include/kernel/Terminal/Serial.h

@@ -41,7 +41,7 @@ namespace Kernel
 		
 		virtual uint32_t width() const override;
 		virtual uint32_t height() const override;
-		virtual void putchar(uint8_t) override;
+		virtual void putchar_impl(uint8_t) override;
 
 		virtual void update() override;
 

kernel/include/kernel/Terminal/TTY.h

@@ -21,6 +21,8 @@ namespace Kernel
 		void set_foreground_pgrp(pid_t pgrp) { m_foreground_pgrp = pgrp; }
 		pid_t foreground_pgrp() const { return m_foreground_pgrp; }
 
+		BAN::ErrorOr<void> tty_ctrl(int command, int flags);
+
 		// for kprint
 		static void putchar_current(uint8_t ch);
 		static bool is_initialized();
@@ -35,7 +37,8 @@ namespace Kernel
 
 		virtual uint32_t height() const = 0;
 		virtual uint32_t width() const = 0;
-		virtual void putchar(uint8_t ch) = 0;
+		void putchar(uint8_t ch);
+		virtual void putchar_impl(uint8_t ch) = 0;
 
 		bool has_data() const;
 
@@ -62,6 +65,14 @@ namespace Kernel
 	private:
 		pid_t m_foreground_pgrp { 0 };
 
+		struct tty_ctrl_t
+		{
+			bool draw_graphics { true };
+			bool receive_input { true };
+			Semaphore semaphore;
+		};
+		tty_ctrl_t m_tty_ctrl;
+
 		struct Buffer
 		{
 			BAN::Array<uint8_t, 1024> buffer;

kernel/include/kernel/Terminal/VirtualTTY.h

@@ -21,7 +21,7 @@ namespace Kernel
 
 		virtual uint32_t height() const override { return m_height; }
 		virtual uint32_t width() const override { return m_width; }
-		virtual void putchar(uint8_t ch) override;
+		virtual void putchar_impl(uint8_t ch) override;
 
 	protected:
 		virtual BAN::StringView name() const override { return m_name; }

kernel/kernel/Process.cpp

@@ -883,6 +883,19 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_tty_ctrl(int fildes, int command, int flags)
+	{
+		LockGuard _(m_lock);
+
+		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
+		if (!inode->is_tty())
+			return BAN::Error::from_errno(ENOTTY);
+		
+		TRY(((TTY*)inode.ptr())->tty_ctrl(command, flags));
+
+		return 0;
+	}
+
 	BAN::ErrorOr<long> Process::sys_termid(char* buffer)
 	{
 		LockGuard _(m_lock);

kernel/kernel/Syscall.cpp

@@ -193,6 +193,9 @@ namespace Kernel
 		case SYS_MUNMAP:
 			ret = Process::current().sys_munmap((void*)arg1, (size_t)arg2);
 			break;
+		case SYS_TTY_CTRL:
+			ret = Process::current().sys_tty_ctrl((int)arg1, (int)arg2, (int)arg3);
+			break;
 		default:
 			dwarnln("Unknown syscall {}", syscall);
 			break;

kernel/kernel/Terminal/Serial.cpp

@@ -286,7 +286,7 @@ namespace Kernel
 		return m_serial.height();
 	}
 
-	void SerialTTY::putchar(uint8_t ch)
+	void SerialTTY::putchar_impl(uint8_t ch)
 	{
 		m_serial.putchar(ch);
 	}

kernel/kernel/Terminal/TTY.cpp

@@ -10,6 +10,7 @@
 
 #include <fcntl.h>
 #include <string.h>
+#include <sys/banan-os.h>
 #include <sys/sysmacros.h>
 
 namespace Kernel
@@ -42,6 +43,35 @@ namespace Kernel
 			MUST(((RamSymlinkInode*)inode.ptr())->set_link_target(name()));
 	}
 
+	BAN::ErrorOr<void> TTY::tty_ctrl(int command, int flags)
+	{
+		if (flags & ~(TTY_FLAG_ENABLE_INPUT | TTY_FLAG_ENABLE_OUTPUT))
+			return BAN::Error::from_errno(EINVAL);
+
+		switch (command)
+		{
+			case TTY_CMD_SET:
+				if ((flags & TTY_FLAG_ENABLE_INPUT) && !m_tty_ctrl.receive_input)
+				{
+					m_tty_ctrl.receive_input = true;
+					m_tty_ctrl.semaphore.unblock();
+				}
+				if (flags & TTY_FLAG_ENABLE_OUTPUT)
+					m_tty_ctrl.draw_graphics = true;
+				break;
+			case TTY_CMD_UNSET:
+				if ((flags & TTY_FLAG_ENABLE_INPUT) && m_tty_ctrl.receive_input)
+					m_tty_ctrl.receive_input = false;
+				if (flags & TTY_FLAG_ENABLE_OUTPUT)
+					m_tty_ctrl.draw_graphics = false;
+				break;
+			default:
+				return BAN::Error::from_errno(EINVAL);
+		}
+
+		return {};
+	}
+
 	void TTY::initialize_devices()
 	{
 		static bool initialized = false;
@@ -53,6 +83,9 @@ namespace Kernel
 				auto inode = MUST(VirtualFileSystem::get().file_from_absolute_path({ 0, 0, 0, 0 }, "/dev/input0"sv, O_RDONLY)).inode;
 				while (true)
 				{
+					while (!TTY::current()->m_tty_ctrl.receive_input)
+						TTY::current()->m_tty_ctrl.semaphore.block();
+
 					Input::KeyEvent event;
 					size_t read = MUST(inode->read(0, &event, sizeof(event)));
 					ASSERT(read == sizeof(event));
@@ -251,6 +284,12 @@ namespace Kernel
 		}
 	}
 
+	void TTY::putchar(uint8_t ch)
+	{
+		if (m_tty_ctrl.draw_graphics)
+			putchar_impl(ch);
+	}
+
 	BAN::ErrorOr<size_t> TTY::read_impl(off_t, void* buffer, size_t count)
 	{
 		LockGuard _(m_lock);

kernel/kernel/Terminal/VirtualTTY.cpp

@@ -304,7 +304,7 @@ namespace Kernel
 		m_terminal_driver->putchar_at(codepoint, x, y, m_foreground, m_background);
 	}
 
-	void VirtualTTY::putchar(uint8_t ch)
+	void VirtualTTY::putchar_impl(uint8_t ch)
 	{
 		ASSERT(m_lock.is_locked());
 		

libc/CMakeLists.txt

@@ -14,6 +14,7 @@ set(LIBC_SOURCES
 	stdio.cpp
 	stdlib.cpp
 	string.cpp
+	sys/banan-os.cpp
 	sys/mman.cpp
 	sys/stat.cpp
 	sys/wait.cpp

libc/include/sys/banan-os.h

@@ -0,0 +1,25 @@
+#ifndef _SYS_BANAN_OS_H
+#define _SYS_BANAN_OS_H 1
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define TTY_CMD_SET		0x01
+#define TTY_CMD_UNSET	0x02
+
+#define TTY_FLAG_ENABLE_OUTPUT	1
+#define TTY_FLAG_ENABLE_INPUT	2
+
+/*
+fildes:		refers to valid tty device
+command:	one of TTY_CMD_* definitions
+flags:		bitwise or of TTY_FLAG_* definitions
+
+return value: 0 on success, -1 on failure and errno set to the error
+*/
+int tty_ctrl(int fildes, int command, int flags);
+
+__END_DECLS
+
+#endif

libc/include/sys/syscall.h

@@ -53,6 +53,7 @@ __BEGIN_DECLS
 #define SYS_SYNC 50
 #define SYS_MMAP 51
 #define SYS_MUNMAP 52
+#define SYS_TTY_CTRL 53
 
 __END_DECLS
 

libc/sys/banan-os.cpp

@@ -0,0 +1,8 @@
+#include <sys/banan-os.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+int tty_ctrl(int fildes, int command, int flags)
+{
+	return syscall(SYS_TTY_CTRL, fildes, command, flags);
+}