From 4b0be17c719bb867c18da6055c2daa4371f632c0 Mon Sep 17 00:00:00 2001
From: Peter Elliott <pelliott@ualberta.ca>
Date: Thu, 28 Apr 2022 01:17:32 -0600
Subject: [PATCH] Kernel: Support userspace TTY graphics modesetting

This is a copy of linux's KDSETMODE/KDGETMODE console ioctl(2)
interface.
---
 Kernel/TTY/TTY.cpp                          | 13 +++++++++++++
 Kernel/TTY/TTY.h                            |  3 +++
 Kernel/TTY/VirtualConsole.h                 |  5 +++--
 Userland/Libraries/LibC/sys/ioctl_numbers.h |  9 +++++++++
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/Kernel/TTY/TTY.cpp b/Kernel/TTY/TTY.cpp
index 841e73720ff..77bb9ed645d 100644
--- a/Kernel/TTY/TTY.cpp
+++ b/Kernel/TTY/TTY.cpp
@@ -562,6 +562,19 @@ ErrorOr<void> TTY::ioctl(OpenFileDescription&, unsigned request, Userspace<void*
     case TIOCNOTTY:
         current_process.set_tty(nullptr);
         return {};
+    case KDSETMODE: {
+        auto mode = static_cast<unsigned int>(arg.ptr());
+        if (mode != KD_TEXT && mode != KD_GRAPHICS)
+            return EINVAL;
+
+        set_graphical(mode == KD_GRAPHICS);
+        return {};
+    }
+    case KDGETMODE: {
+        auto mode_ptr = static_ptr_cast<int*>(arg);
+        int mode = (is_graphical()) ? KD_GRAPHICS : KD_TEXT;
+        return copy_to_user(mode_ptr, &mode);
+    }
     }
     return EINVAL;
 }
diff --git a/Kernel/TTY/TTY.h b/Kernel/TTY/TTY.h
index 881fe905239..76a811373ac 100644
--- a/Kernel/TTY/TTY.h
+++ b/Kernel/TTY/TTY.h
@@ -48,6 +48,9 @@ public:
 
     virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_name() const = 0;
 
+    virtual bool is_graphical() const { return false; }
+    virtual void set_graphical(bool) { }
+
 protected:
     virtual ErrorOr<size_t> on_tty_write(UserOrKernelBuffer const&, size_t) = 0;
     void set_size(unsigned short columns, unsigned short rows);
diff --git a/Kernel/TTY/VirtualConsole.h b/Kernel/TTY/VirtualConsole.h
index 615ad4cf168..13a8add281a 100644
--- a/Kernel/TTY/VirtualConsole.h
+++ b/Kernel/TTY/VirtualConsole.h
@@ -78,8 +78,9 @@ public:
 
     void refresh_after_resolution_change();
 
-    bool is_graphical() { return m_graphical; }
-    void set_graphical(bool graphical);
+    // ^TTY
+    virtual bool is_graphical() const override { return m_graphical; }
+    virtual void set_graphical(bool graphical) override;
 
     void emit_char(char);
 
diff --git a/Userland/Libraries/LibC/sys/ioctl_numbers.h b/Userland/Libraries/LibC/sys/ioctl_numbers.h
index 2a97ea41ab3..a1a314e3783 100644
--- a/Userland/Libraries/LibC/sys/ioctl_numbers.h
+++ b/Userland/Libraries/LibC/sys/ioctl_numbers.h
@@ -74,6 +74,11 @@ struct FBFlushRects {
     struct FBRect const* rects;
 };
 
+enum ConsoleModes {
+    KD_TEXT = 0x00,
+    KD_GRAPHICS = 0x01,
+};
+
 __END_DECLS
 
 enum IOCtlNumber {
@@ -132,6 +137,8 @@ enum IOCtlNumber {
     VIRGL_IOCTL_CREATE_RESOURCE,
     VIRGL_IOCTL_SUBMIT_CMD,
     VIRGL_IOCTL_TRANSFER_DATA,
+    KDSETMODE,
+    KDGETMODE,
 };
 
 #define TIOCGPGRP TIOCGPGRP
@@ -184,3 +191,5 @@ enum IOCtlNumber {
 #define VIRGL_IOCTL_CREATE_RESOURCE VIRGL_IOCTL_CREATE_RESOURCE
 #define VIRGL_IOCTL_SUBMIT_CMD VIRGL_IOCTL_SUBMIT_CMD
 #define VIRGL_IOCTL_TRANSFER_DATA VIRGL_IOCTL_TRANSFER_DATA
+#define KDSETMODE KDSETMODE
+#define KDGETMODE KDGETMODE