text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   *
   * SPDX-License-Identifier: BSD-2-Clause
   */
  
  #include <AK/StringBuilder.h>
  #include <Kernel/CommandLine.h>
  #include <Kernel/Panic.h>
  #include <Kernel/Sections.h>
  #include <Kernel/StdLib.h>
  
  namespace Kernel {
  
  static char s_cmd_line[1024];
  static constexpr StringView s_embedded_cmd_line = "";
  static CommandLine* s_the;
  
  UNMAP_AFTER_INIT void CommandLine::early_initialize(const char* cmd_line)
  {
      if (!cmd_line)
          return;
      size_t length = strlen(cmd_line);
      if (length >= sizeof(s_cmd_line))
          length = sizeof(s_cmd_line) - 1;
      memcpy(s_cmd_line, cmd_line, length);
      s_cmd_line[length] = '\0';
  }
  
  const CommandLine& kernel_command_line()
  {
      VERIFY(s_the);
      return *s_the;
  }
  
  UNMAP_AFTER_INIT void CommandLine::initialize()
  {
      VERIFY(!s_the);
      s_the = new CommandLine(s_cmd_line);
      dmesgln("Kernel Commandline: {}", kernel_command_line().string());
  }
  
  UNMAP_AFTER_INIT void CommandLine::build_commandline(const String& cmdline_from_bootloader)
  {
      StringBuilder builder;
      builder.append(cmdline_from_bootloader);
      if (!s_embedded_cmd_line.is_empty()) {
          builder.append(" ");
          builder.append(s_embedded_cmd_line);
      }
      m_string = builder.to_string();
  }
  
  UNMAP_AFTER_INIT void CommandLine::add_arguments(const Vector<StringView>& args)
  {
      for (auto&& str : args) {
          if (str == ""sv) {
              continue;
          }
  
          auto pair = str.split_view('=', false);
          VERIFY(pair.size() == 2 || pair.size() == 1);
  
          if (pair.size() == 1) {
              m_params.set(move(pair[0]), ""sv);
          } else {
              m_params.set(move(pair[0]), move(pair[1]));
          }
      }
  }
  
  UNMAP_AFTER_INIT CommandLine::CommandLine(const String& cmdline_from_bootloader)
  {
      s_the = this;
      build_commandline(cmdline_from_bootloader);
      const auto& args = m_string.split_view(' ');
      m_params.ensure_capacity(args.size());
      add_arguments(args);
  }
  
  Optional<String> CommandLine::lookup(const StringView& key) const
  {
      return m_params.get(key);
  }
  
  bool CommandLine::contains(const StringView& key) const
  {
      return m_params.contains(key);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_boot_profiling_enabled() const
  {
      return contains("boot_prof"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_ide_enabled() const
  {
      return !contains("disable_ide"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_smp_enabled() const
  {
      return lookup("smp"sv).value_or("off"sv) == "on"sv;
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_vmmouse_enabled() const
  {
      return lookup("vmmouse"sv).value_or("on") == "on"sv;
  }
  
  UNMAP_AFTER_INIT PCIAccessLevel CommandLine::pci_access_level() const
  {
      auto value = lookup("pci_ecam"sv).value_or("off"sv);
      if (value == "on"sv)
          return PCIAccessLevel::MappingPerBus;
      if (value == "per-device"sv)
          return PCIAccessLevel::MappingPerDevice;
      if (value == "off"sv)
          return PCIAccessLevel::IOAddressing;
      PANIC("Unknown PCI ECAM setting: {}", value);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_legacy_time_enabled() const
  {
      return lookup("time"sv).value_or("modern"sv) == "legacy"sv;
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_force_pio() const
  {
      return contains("force_pio"sv);
  }
  
  UNMAP_AFTER_INIT String CommandLine::root_device() const
  {
      return lookup("root"sv).value_or("/dev/hda"sv);
  }
  
  UNMAP_AFTER_INIT AcpiFeatureLevel CommandLine::acpi_feature_level() const
  {
      auto value = kernel_command_line().lookup("acpi"sv).value_or("on"sv);
      if (value == "limited"sv)
          return AcpiFeatureLevel::Limited;
      if (value == "off"sv)
          return AcpiFeatureLevel::Disabled;
      return AcpiFeatureLevel::Enabled;
  }
  
  UNMAP_AFTER_INIT HPETMode CommandLine::hpet_mode() const
  {
      auto hpet_mode = lookup("hpet"sv).value_or("periodic"sv);
      if (hpet_mode == "periodic"sv)
          return HPETMode::Periodic;
      if (hpet_mode == "nonperiodic"sv)
          return HPETMode::NonPeriodic;
      PANIC("Unknown HPETMode: {}", hpet_mode);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_physical_networking_disabled() const
  {
      return contains("disable_physical_networking"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::disable_ps2_controller() const
  {
      return contains("disable_ps2_controller"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::disable_physical_storage() const
  {
      return contains("disable_physical_storage"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::disable_uhci_controller() const
  {
      return contains("disable_uhci_controller"sv);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::disable_virtio() const
  {
      return contains("disable_virtio"sv);
  }
  
  UNMAP_AFTER_INIT AHCIResetMode CommandLine::ahci_reset_mode() const
  {
      const auto ahci_reset_mode = lookup("ahci_reset_mode"sv).value_or("controllers"sv);
      if (ahci_reset_mode == "controllers"sv) {
          return AHCIResetMode::ControllerOnly;
      } else if (ahci_reset_mode == "aggressive"sv) {
          return AHCIResetMode::Aggressive;
      }
      PANIC("Unknown AHCIResetMode: {}", ahci_reset_mode);
  }
  
  BootMode CommandLine::boot_mode() const
  {
      const auto boot_mode = lookup("boot_mode"sv).value_or("graphical"sv);
      if (boot_mode == "no-fbdev"sv) {
          return BootMode::NoFramebufferDevices;
      } else if (boot_mode == "self-test"sv) {
          return BootMode::SelfTest;
      } else if (boot_mode == "graphical"sv) {
          return BootMode::Graphical;
      }
      PANIC("Unknown BootMode: {}", boot_mode);
  }
  
  UNMAP_AFTER_INIT bool CommandLine::is_no_framebuffer_devices_mode() const
  {
      const auto mode = boot_mode();
      return mode == BootMode::NoFramebufferDevices || mode == BootMode::SelfTest;
  }
  
  String CommandLine::userspace_init() const
  {
      return lookup("init"sv).value_or("/bin/SystemServer"sv);
  }
  
  Vector<String> CommandLine::userspace_init_args() const
  {
      auto init_args = lookup("init_args"sv).value_or(""sv).split(',');
      if (!init_args.is_empty())
          init_args.prepend(userspace_init());
  
      return init_args;
  }
  
  UNMAP_AFTER_INIT size_t CommandLine::switch_to_tty() const
  {
      const auto default_tty = lookup("switch_to_tty"sv).value_or("1"sv);
      auto switch_tty_number = default_tty.to_uint();
      if (switch_tty_number.has_value() && switch_tty_number.value() >= 1) {
          return switch_tty_number.value() - 1;
      }
      PANIC("Invalid default tty value: {}", default_tty);
  }
  }
  