text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  
  #include <AK/String.h>
  #include <AK/Types.h>
  #include <Kernel/Devices/BlockDevice.h>
  #include <Kernel/PhysicalAddress.h>
  
  namespace Kernel {
  
  class BXVGADevice final : public BlockDevice {
      AK_MAKE_ETERNAL
  public:
      static BXVGADevice& the();
  
      BXVGADevice();
  
      virtual int ioctl(FileDescription&, unsigned request, FlatPtr arg) override;
      virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress preferred_vaddr, size_t offset, size_t, int prot, bool shared) override;
  
  private:
      virtual const char* class_name() const override { return "BXVGA"; }
      virtual bool can_read(const FileDescription&, size_t) const override { return true; }
      virtual bool can_write(const FileDescription&, size_t) const override { return true; }
      virtual KResultOr<size_t> read(FileDescription&, size_t, u8*, size_t) override { return -EINVAL; }
      virtual KResultOr<size_t> write(FileDescription&, size_t, const u8*, size_t) override { return -EINVAL; }
      virtual bool read_blocks(unsigned, u16, u8*) override { return false; }
      virtual bool write_blocks(unsigned, u16, const u8*) override { return false; }
  
      void set_safe_resolution();
  
      void set_register(u16 index, u16 value);
      u16 get_register(u16 index);
      bool validate_setup_resolution(size_t width, size_t height);
      u32 find_framebuffer_address();
      void revert_resolution();
      bool test_resolution(size_t width, size_t height);
      size_t framebuffer_size_in_bytes() const { return m_framebuffer_pitch * m_framebuffer_height * 2; }
      bool set_resolution(size_t width, size_t height);
      void set_resolution_registers(size_t width, size_t height);
      void set_y_offset(size_t);
  
      PhysicalAddress m_framebuffer_address;
      size_t m_framebuffer_pitch { 0 };
      size_t m_framebuffer_width { 0 };
      size_t m_framebuffer_height { 0 };
      size_t m_y_offset { 0 };
  };
  
  }
  