diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index 339b429..5d136b2 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -251,7 +251,7 @@
    -- Maximum source width with enabled scaler. This only accounts
    -- for simple 1:1 pipe:scaler mappings.
 
-   type Width_Per_Pipe is array (Pipe_Index) of Width_Type;
+   type Width_Per_Pipe is array (Pipe_Index) of Pos16;
 
    Maximum_Scalable_Width : constant Width_Per_Pipe :=
      (case CPU is
diff --git a/common/hw-gfx-gma-config_helpers.adb b/common/hw-gfx-gma-config_helpers.adb
index 6eff5d2..f2b4ef6 100644
--- a/common/hw-gfx-gma-config_helpers.adb
+++ b/common/hw-gfx-gma-config_helpers.adb
@@ -181,9 +181,9 @@
    -- Validates that a given configuration should work with
    -- a given framebuffer.
    function Validate_Config
-     (Framebuffer : Framebuffer_Type;
-      Port_Cfg    : Port_Config;
-      Pipe        : Pipe_Index)
+     (FB       : Framebuffer_Type;
+      Port_Cfg : Port_Config;
+      Pipe     : Pipe_Index)
       return Boolean
    is
    begin
@@ -193,18 +193,21 @@
       -- Only 32bpp RGB (ignored for VGA plane)
       -- Stride must be big enough and a multiple of 64 bytes or the tile size
       -- (ignored for VGA plane)
-      -- Tiling is only supported on newer generations (with Plane_Control)
+      -- Tiling and rotation is only supported on newer generations (with
+      -- Plane_Control)
+      -- 90 degree rotations are only supported with Y-tiling
       return
-         ((Framebuffer.Width = Pos32 (Port_Cfg.Mode.H_Visible) and
-           Framebuffer.Height = Pos32 (Port_Cfg.Mode.V_Visible)) or
-          (Framebuffer.Width <= Config.Maximum_Scalable_Width (Pipe) and
-           Framebuffer.Width <= Pos32 (Port_Cfg.Mode.H_Visible) and
-           Framebuffer.Height <= Pos32 (Port_Cfg.Mode.V_Visible))) and
-         (Framebuffer.Offset /= VGA_PLANE_FRAMEBUFFER_OFFSET or Pipe = Primary)
-         and
-         (Framebuffer.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
-          (Framebuffer.BPC = 8 and Valid_Stride (Framebuffer) and
-           (Config.Has_Plane_Control or Framebuffer.Tiling = Linear)));
+         ((Rotated_Width (FB) = Port_Cfg.Mode.H_Visible and
+           Rotated_Height (FB) = Port_Cfg.Mode.V_Visible) or
+          (Rotated_Width (FB) <= Config.Maximum_Scalable_Width (Pipe) and
+           Rotated_Width (FB) <= Port_Cfg.Mode.H_Visible and
+           Rotated_Height (FB) <= Port_Cfg.Mode.V_Visible)) and
+         (FB.Offset /= VGA_PLANE_FRAMEBUFFER_OFFSET or Pipe = Primary) and
+         (FB.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
+          (FB.BPC = 8 and Valid_Stride (FB) and
+           (Config.Has_Plane_Control or
+            (FB.Tiling = Linear and FB.Rotation = No_Rotation)) and
+           (FB.Tiling = Y_Tiled or not Rotation_90 (FB))));
    end Validate_Config;
 
 end HW.GFX.GMA.Config_Helpers;
diff --git a/common/hw-gfx-gma-config_helpers.ads b/common/hw-gfx-gma-config_helpers.ads
index a9cde2b..e684f22 100644
--- a/common/hw-gfx-gma-config_helpers.ads
+++ b/common/hw-gfx-gma-config_helpers.ads
@@ -40,14 +40,16 @@
    use type HW.Pos32;
    pragma Warnings (GNAT, On, """Integer_32"" is already use-visible *");
    function Validate_Config
-     (Framebuffer : Framebuffer_Type;
-      Port_Cfg    : Port_Config;
-      Pipe        : Pipe_Index)
+     (FB       : Framebuffer_Type;
+      Port_Cfg : Port_Config;
+      Pipe     : Pipe_Index)
       return Boolean
    with
       Post =>
         (if Validate_Config'Result then
-            Framebuffer.Width <= Pos32 (Port_Cfg.Mode.H_Visible) and
-            Framebuffer.Height <= Pos32 (Port_Cfg.Mode.V_Visible));
+            Rotated_Width (FB) <= Port_Cfg.Mode.H_Visible and
+            Rotated_Height (FB) <= Port_Cfg.Mode.V_Visible and
+            (FB.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
+             FB.Height <= FB.V_Stride));
 
 end HW.GFX.GMA.Config_Helpers;
diff --git a/common/hw-gfx-gma-pipe_setup.adb b/common/hw-gfx-gma-pipe_setup.adb
index 215b4de..e1ff835 100644
--- a/common/hw-gfx-gma-pipe_setup.adb
+++ b/common/hw-gfx-gma-pipe_setup.adb
@@ -50,6 +50,13 @@
       X_Tiled  => PLANE_CTL_TILED_SURFACE_X_TILED,
       Y_Tiled  => PLANE_CTL_TILED_SURFACE_Y_TILED);
 
+   PLANE_CTL_PLANE_ROTATION_MASK       : constant := 3 * 2 ** 0;
+   PLANE_CTL_PLANE_ROTATION : constant array (Rotation_Type) of Word32 :=
+     (No_Rotation => 0 * 2 ** 0,
+      Rotated_90  => 1 * 2 ** 0,
+      Rotated_180 => 2 * 2 ** 0,
+      Rotated_270 => 3 * 2 ** 0);
+
    PLANE_WM_ENABLE                     : constant :=        1 * 2 ** 31;
    PLANE_WM_LINES_SHIFT                : constant :=                 14;
    PLANE_WM_LINES_MASK                 : constant := 16#001f# * 2 ** 14;
@@ -149,7 +156,8 @@
             =>+
               (Registers.Register_State,
                Controller,
-               FB))
+               FB)),
+      Pre => FB.Height <= FB.V_Stride
    is
       -- FIXME: setup correct format, based on framebuffer RGB format
       Format : constant Word32 := 6 * 2 ** 26;
@@ -158,20 +166,34 @@
       pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
 
       if Config.Has_Plane_Control then
-         Registers.Write
-           (Register    => Controller.PLANE_CTL,
-            Value       => PLANE_CTL_PLANE_ENABLE or
-                           PLANE_CTL_SRC_PIX_FMT_RGB_32B_8888 or
-                           PLANE_CTL_PLANE_GAMMA_DISABLE or
-                           PLANE_CTL_TILED_SURFACE (FB.Tiling));
-         Registers.Write (Controller.PLANE_OFFSET, 16#0000_0000#);
-         Registers.Write
-           (Controller.PLANE_SIZE,
-            Encode (Pos16 (FB.Width), Pos16 (FB.Height)));
-         Registers.Write
-           (Controller.PLANE_STRIDE, Word32 (FB_Pitch (FB.Stride, FB)));
-         Registers.Write (Controller.PLANE_POS,    16#0000_0000#);
-         Registers.Write (Controller.PLANE_SURF,   FB.Offset and 16#ffff_f000#);
+         declare
+            Stride, Offset, GTT_Addr : Word32;
+            Width : constant Pos16 := Rotated_Width (FB);
+            Height : constant Pos16 := Rotated_Height (FB);
+         begin
+            if Rotation_90 (FB) then
+               Stride            := Word32 (FB_Pitch (FB.V_Stride, FB));
+               Offset            := Word32 (FB.V_Stride - FB.Height);
+               GTT_Addr          :=
+                  FB.Offset + Word32 (GTT_Rotation_Offset) * GTT_Page_Size;
+            else
+               Stride            := Word32 (FB_Pitch (FB.Stride, FB));
+               Offset            := 0;
+               GTT_Addr          := FB.Offset;
+            end if;
+            Registers.Write
+              (Register    => Controller.PLANE_CTL,
+               Value       => PLANE_CTL_PLANE_ENABLE or
+                              PLANE_CTL_SRC_PIX_FMT_RGB_32B_8888 or
+                              PLANE_CTL_PLANE_GAMMA_DISABLE or
+                              PLANE_CTL_TILED_SURFACE (FB.Tiling) or
+                              PLANE_CTL_PLANE_ROTATION (FB.Rotation));
+            Registers.Write (Controller.PLANE_OFFSET, Offset);
+            Registers.Write (Controller.PLANE_SIZE, Encode (Width, Height));
+            Registers.Write (Controller.PLANE_STRIDE, Stride);
+            Registers.Write (Controller.PLANE_POS, 16#0000_0000#);
+            Registers.Write (Controller.PLANE_SURF, GTT_Addr and 16#ffff_f000#);
+         end;
       else
          if Config.Disable_Trickle_Feed then
             PRI := PRI or DSPCNTR_DISABLE_TRICKLE_FEED;
@@ -210,7 +232,10 @@
                Dither),
          Port_IO.State
             =>+
-               (Framebuffer))
+               (Framebuffer)),
+      Pre =>
+         Framebuffer.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
+         Framebuffer.Height <= Framebuffer.V_Stride
    is
       use type Word8;
 
@@ -252,7 +277,7 @@
       Registers.Write
         (Register => Controller.PIPESRC,
          Value    => Encode
-           (Pos16 (Framebuffer.Height), Pos16 (Framebuffer.Width)));
+           (Rotated_Height (Framebuffer), Rotated_Width (Framebuffer)));
 
       if Config.Has_Pipeconf_Misc then
          Registers.Write
@@ -273,19 +298,21 @@
       Pre =>
          Max_Width <= Pos32 (Pos16'Last) and
          Max_Height <= Pos32 (Pos16'Last) and
-         Framebuffer.Width <= Max_Width and
-         Framebuffer.Height <= Max_Height,
+         Pos32 (Rotated_Width (Framebuffer)) <= Max_Width and
+         Pos32 (Rotated_Height (Framebuffer)) <= Max_Height,
       Post =>
          Width <= Max_Width and Height <= Max_Height
    is
+      Src_Width : constant Pos32 := Pos32 (Rotated_Width (Framebuffer));
+      Src_Height : constant Pos32 := Pos32 (Rotated_Height (Framebuffer));
    begin
-      if (Max_Width * Framebuffer.Height) / Framebuffer.Width <= Max_Height then
+      if (Max_Width * Src_Height) / Src_Width <= Max_Height then
          Width  := Max_Width;
-         Height := (Max_Width * Framebuffer.Height) / Framebuffer.Width;
+         Height := (Max_Width * Src_Height) / Src_Width;
       else
          Height := Max_Height;
          Width  := Pos32'Min (Max_Width,  -- could prove, it's <= Max_Width
-            (Max_Height * Framebuffer.Width) / Framebuffer.Height);
+            (Max_Height * Src_Width) / Src_Height);
       end if;
    end Scale_Keep_Aspect;
 
@@ -295,8 +322,8 @@
       Framebuffer : in     HW.GFX.Framebuffer_Type)
    with
       Pre =>
-         Framebuffer.Width <= Pos32 (Mode.H_Visible) and
-         Framebuffer.Height <= Pos32 (Mode.V_Visible)
+         Rotated_Width (Framebuffer) <= Mode.H_Visible and
+         Rotated_Height (Framebuffer) <= Mode.V_Visible
    is
       use type Registers.Registers_Invalid_Index;
 
@@ -305,14 +332,17 @@
         (if Controller.PS_CTRL_2 /= Registers.Invalid_Register then
             PS_CTRL_SCALER_MODE_7X5_EXTENDED else 0);
 
+      Width_In    : constant Pos32 := Pos32 (Rotated_Width (Framebuffer));
+      Height_In   : constant Pos32 := Pos32 (Rotated_Height (Framebuffer));
+
       -- We can scale up to 2.99x horizontally:
-      Horizontal_Limit : constant Pos32 := ((Framebuffer.Width * 299) / 100);
+      Horizontal_Limit : constant Pos32 := (Width_In * 299) / 100;
       -- The third scaler is limited to 1.99x
       -- vertical scaling for source widths > 2048:
       Vertical_Limit : constant Pos32 :=
-        (Framebuffer.Height *
+        (Height_In *
            (if Controller.PS_CTRL_2 = Registers.Invalid_Register and
-               Framebuffer.Width > 2048
+               Width_In > 2048
             then
                199
             else
@@ -348,8 +378,8 @@
       Framebuffer : in     HW.GFX.Framebuffer_Type)
    with
       Pre =>
-         Framebuffer.Width <= Pos32 (Mode.H_Visible) and
-         Framebuffer.Height <= Pos32 (Mode.V_Visible)
+         Rotated_Width (Framebuffer) <= Mode.H_Visible and
+         Rotated_Height (Framebuffer) <= Mode.V_Visible
    is
       -- Force 1:1 mapping of panel fitter:pipe
       PF_Ctrl_Pipe_Sel : constant Word32 :=
@@ -390,12 +420,12 @@
       Framebuffer : in     HW.GFX.Framebuffer_Type)
    with
       Pre =>
-         Framebuffer.Width <= Pos32 (Mode.H_Visible) and
-         Framebuffer.Height <= Pos32 (Mode.V_Visible)
+         Rotated_Width (Framebuffer) <= Mode.H_Visible and
+         Rotated_Height (Framebuffer) <= Mode.V_Visible
    is
    begin
-      if Framebuffer.Width /= Pos32 (Mode.H_Visible) or
-         Framebuffer.Height /= Pos32 (Mode.V_Visible)
+      if Rotated_Width (Framebuffer) /= Mode.H_Visible or
+         Rotated_Height (Framebuffer) /= Mode.V_Visible
       then
          if Config.Has_Plane_Control then
             Setup_Skylake_Pipe_Scaler (Controller, Mode, Framebuffer);
diff --git a/common/hw-gfx-gma-pipe_setup.ads b/common/hw-gfx-gma-pipe_setup.ads
index 725bc08..35d9e87 100644
--- a/common/hw-gfx-gma-pipe_setup.ads
+++ b/common/hw-gfx-gma-pipe_setup.ads
@@ -25,8 +25,10 @@
       Framebuffer : Framebuffer_Type)
    with
       Pre =>
-         Framebuffer.Width <= Pos32 (Port_Cfg.Mode.H_Visible) and
-         Framebuffer.Height <= Pos32 (Port_Cfg.Mode.V_Visible);
+         Rotated_Width (Framebuffer) <= Port_Cfg.Mode.H_Visible and
+         Rotated_Height (Framebuffer) <= Port_Cfg.Mode.V_Visible and
+         (Framebuffer.Offset = VGA_PLANE_FRAMEBUFFER_OFFSET or
+          Framebuffer.Height <= Framebuffer.V_Stride);
 
    procedure Off (Pipe : Pipe_Index);
 
diff --git a/common/hw-gfx-gma.adb b/common/hw-gfx-gma.adb
index e4ad3b3..d8438ab 100644
--- a/common/hw-gfx-gma.adb
+++ b/common/hw-gfx-gma.adb
@@ -479,7 +479,7 @@
 
    -- Check basics and that it fits in GTT
    function Valid_FB (FB : Framebuffer_Type) return Boolean is
-     (Valid_Stride (FB) and FB_Last_Page (FB) <= GTT_Range'Last);
+     (Valid_Stride (FB) and FB_Last_Page (FB) < GTT_Rotation_Offset);
 
    -- Also check that we don't overflow the GTT's 39-bit space
    -- (always true with a 32-bit base)
@@ -514,6 +514,30 @@
             Valid          => True);
          Phys_Addr := Phys_Addr + GTT_Page_Size;
       end loop;
+
+      if Rotation_90 (FB) and FB.Tiling = Y_Tiled and FB.V_Stride >= 32 then
+         declare
+            V_Pages : constant Natural := Natural (FB.V_Stride) / 32;
+            Bytes_Per_Row : constant GTT_Address_Type :=
+               GTT_Address_Type (Pixel_To_Bytes (32 * FB.Stride, FB));
+         begin
+            Phys_Addr := GTT_Address_Type (Phys_Base) +
+                           GTT_Address_Type (FB.Offset) +
+                           GTT_Address_Type (FB_Size (FB));
+            for Page in FB_First_Page (FB) .. FB_Last_Page (FB) loop
+               Phys_Addr := Phys_Addr - Bytes_Per_Row;
+               Registers.Write_GTT
+                 (GTT_Page       => GTT_Rotation_Offset + Page,
+                  Device_Address => Phys_Addr,
+                  Valid          => True);
+
+               if (Page - FB_First_Page (FB) + 1) mod V_Pages = 0 then
+                  Phys_Addr := Phys_Addr + GTT_Page_Size +
+                                 GTT_Address_Type (V_Pages) * Bytes_Per_Row;
+               end if;
+            end loop;
+         end;
+      end if;
    end Setup_Default_GTT;
 
    ----------------------------------------------------------------------------
diff --git a/common/hw-gfx-gma.ads b/common/hw-gfx-gma.ads
index 9943e44..50a76a0 100644
--- a/common/hw-gfx-gma.ads
+++ b/common/hw-gfx-gma.ads
@@ -95,6 +95,8 @@
    GTT_Page_Size : constant := 4096;
    type GTT_Address_Type is mod 2 ** 39;
    subtype GTT_Range is Natural range 0 .. 16#8_0000# - 1;
+   GTT_Rotation_Offset : constant GTT_Range := GTT_Range'Last / 2 + 1;
+
    procedure Write_GTT
      (GTT_Page       : GTT_Range;
       Device_Address : GTT_Address_Type;
@@ -161,6 +163,8 @@
 
    Tile_Width : constant array (Tiling_Type) of Pos32 :=
      (Linear => 16, X_Tiled => 128, Y_Tiled => 32);
+   Tile_Rows : constant array (Tiling_Type) of Pos32 :=
+     (Linear => 1, X_Tiled => 8, Y_Tiled => 32);
 
    function FB_Pitch (Px : Pixel_Type; FB : Framebuffer_Type) return Natural is
      (Natural (Div_Round_Up
@@ -168,6 +172,8 @@
 
    function Valid_Stride (FB : Framebuffer_Type) return Boolean is
      (FB.Width <= FB.Stride and
-      Pixel_To_Bytes (FB.Stride, FB) mod (Tile_Width (FB.Tiling) * 4) = 0);
+      Pixel_To_Bytes (FB.Stride, FB) mod (Tile_Width (FB.Tiling) * 4) = 0 and
+      FB.Height <= FB.V_Stride and
+      FB.V_Stride mod Tile_Rows (FB.Tiling) = 0);
 
 end HW.GFX.GMA;
diff --git a/common/hw-gfx.ads b/common/hw-gfx.ads
index 5594b18..5d8ae59 100644
--- a/common/hw-gfx.ads
+++ b/common/hw-gfx.ads
@@ -47,6 +47,14 @@
       Offset   : Word32;
    end record;
 
+   function Rotation_90 (FB : Framebuffer_Type) return Boolean is
+     (FB.Rotation = Rotated_90 or FB.Rotation = Rotated_270);
+
+   function Rotated_Width (FB : Framebuffer_Type) return Pos16 is
+     (if Rotation_90 (FB) then Pos16 (FB.Height) else Pos16 (FB.Width));
+   function Rotated_Height (FB : Framebuffer_Type) return Pos16 is
+     (if Rotation_90 (FB) then Pos16 (FB.Width) else Pos16 (FB.Height));
+
    function Pixel_To_Bytes (Pixel : Pixel_Type; FB : Framebuffer_Type)
       return Pos32 is (Pixel * Pos32 (FB.BPC) / (8 / 4));
    function FB_Size (FB : Framebuffer_Type) return Pos32 is