SerenityOS · awesomekling · Mar 2, 2022 · Jan 21, 2022 · Jan 21, 2022 · Jan 21, 2022
diff --git a/Base/usr/share/man/man7/boot_parameters.md b/Base/usr/share/man/man7/boot_parameters.md
@@ -56,7 +56,8 @@ List of options:
 
 * **`panic`** - This parameter expects **`halt`** or **`shutdown`**. This is particularly useful in CI contexts.
 
-* **`pci_ecam`** - This parameter expects **`on`** or **`off`**.
+* **`pci`** - This parameter expects **`ecam`**, **`io`** or **`none`**. When selecting **`none`**
+  the kernel will not use PCI resources/devices.
 
 * **`root`** - This parameter configures the device to use as the root file system. It defaults to **`/dev/hda`** if unspecified.
 

diff --git a/Kernel/Bus/PCI/Access.cpp b/Kernel/Bus/PCI/Access.cpp
@@ -11,11 +11,13 @@
 #include <Kernel/Bus/PCI/Access.h>
 #include <Kernel/Bus/PCI/Controller/HostBridge.h>
 #include <Kernel/Bus/PCI/Controller/MemoryBackedHostBridge.h>
+#include <Kernel/Bus/PCI/Initializer.h>
 #include <Kernel/Debug.h>
 #include <Kernel/Firmware/ACPI/Definitions.h>
 #include <Kernel/Memory/MemoryManager.h>
 #include <Kernel/Memory/Region.h>
 #include <Kernel/Memory/TypedMapping.h>
+#include <Kernel/ProcessExposed.h>
 #include <Kernel/Sections.h>
 
 namespace Kernel::PCI {
@@ -37,6 +39,11 @@ bool Access::is_initialized()
     return (s_access != nullptr);
 }
 
+bool Access::is_disabled()
+{
+    return g_pci_access_is_disabled_from_commandline || g_pci_access_io_probe_failed;
+}
+
 UNMAP_AFTER_INIT bool Access::find_and_register_pci_host_bridges_from_acpi_mcfg_table(PhysicalAddress mcfg_table)
 {
     u32 length = 0;
@@ -89,6 +96,7 @@ UNMAP_AFTER_INIT bool Access::find_and_register_pci_host_bridges_from_acpi_mcfg_
 UNMAP_AFTER_INIT bool Access::initialize_for_multiple_pci_domains(PhysicalAddress mcfg_table)
 {
     VERIFY(!Access::is_initialized());
+    ProcFSComponentRegistry::the().root_directory().add_pci_node({});
     auto* access = new Access();
     if (!access->find_and_register_pci_host_bridges_from_acpi_mcfg_table(mcfg_table))
         return false;
@@ -100,6 +108,7 @@ UNMAP_AFTER_INIT bool Access::initialize_for_multiple_pci_domains(PhysicalAddres
 UNMAP_AFTER_INIT bool Access::initialize_for_one_pci_domain()
 {
     VERIFY(!Access::is_initialized());
+    ProcFSComponentRegistry::the().root_directory().add_pci_node({});
     auto* access = new Access();
     auto host_bridge = HostBridge::must_create_with_io_access();
     access->add_host_controller(move(host_bridge));

diff --git a/Kernel/Bus/PCI/Access.h b/Kernel/Bus/PCI/Access.h
@@ -26,6 +26,7 @@ class Access {
 
     static Access& the();
     static bool is_initialized();
+    static bool is_disabled();
 
     void write8_field(Address address, u32 field, u8 value);
     void write16_field(Address address, u32 field, u16 value);

diff --git a/Kernel/Bus/PCI/Initializer.cpp b/Kernel/Bus/PCI/Initializer.cpp
@@ -17,6 +17,9 @@
 namespace Kernel {
 namespace PCI {
 
+READONLY_AFTER_INIT bool g_pci_access_io_probe_failed;
+READONLY_AFTER_INIT bool g_pci_access_is_disabled_from_commandline;
+
 static bool test_pci_io();
 
 UNMAP_AFTER_INIT static PCIAccessLevel detect_optimal_access_type()
@@ -28,14 +31,18 @@ UNMAP_AFTER_INIT static PCIAccessLevel detect_optimal_access_type()
     if (boot_determined != PCIAccessLevel::IOAddressing)
         return boot_determined;
 
-    if (test_pci_io())
+    if (!g_pci_access_io_probe_failed)
         return PCIAccessLevel::IOAddressing;
 
     PANIC("No PCI bus access method detected!");
 }
 
 UNMAP_AFTER_INIT void initialize()
 {
+    g_pci_access_io_probe_failed = !test_pci_io();
+    g_pci_access_is_disabled_from_commandline = kernel_command_line().is_pci_disabled();
+    if (g_pci_access_is_disabled_from_commandline || g_pci_access_io_probe_failed)
+        return;
     switch (detect_optimal_access_type()) {
     case PCIAccessLevel::MemoryAddressing: {
         auto mcfg = ACPI::Parser::the()->find_table("MCFG");

diff --git a/Kernel/Bus/PCI/Initializer.h b/Kernel/Bus/PCI/Initializer.h
@@ -9,6 +9,9 @@
 namespace Kernel {
 namespace PCI {
 
+extern bool g_pci_access_io_probe_failed;
+extern bool g_pci_access_is_disabled_from_commandline;
+
 void initialize();
 
 }

diff --git a/Kernel/CMakeLists.txt b/Kernel/CMakeLists.txt
@@ -82,10 +82,11 @@ set(KERNEL_SOURCES
     Graphics/FramebufferDevice.cpp
     Graphics/GraphicsManagement.cpp
     Graphics/Intel/NativeGraphicsAdapter.cpp
+    Graphics/VGA/ISAAdapter.cpp
+    Graphics/VGA/PCIAdapter.cpp
     Graphics/VirtIOGPU/FramebufferDevice.cpp
     Graphics/VirtIOGPU/Console.cpp
     Graphics/VirtIOGPU/GraphicsAdapter.cpp
-    Graphics/VGACompatibleAdapter.cpp
     Graphics/GenericFramebufferDevice.cpp
     SanCov.cpp
     Storage/ATA/AHCIController.cpp
@@ -95,6 +96,8 @@ set(KERNEL_SOURCES
     Storage/ATA/ATADiskDevice.cpp
     Storage/ATA/ATAPIDiscDevice.cpp
     Storage/ATA/BMIDEChannel.cpp
+    Storage/ATA/ISAIDEController.cpp
+    Storage/ATA/PCIIDEController.cpp
     Storage/ATA/IDEController.cpp
     Storage/ATA/IDEChannel.cpp
     Storage/Partition/DiskPartition.cpp

diff --git a/Kernel/CommandLine.cpp b/Kernel/CommandLine.cpp
@@ -142,14 +142,21 @@ UNMAP_AFTER_INIT bool CommandLine::is_vmmouse_enabled() const
 
 UNMAP_AFTER_INIT PCIAccessLevel CommandLine::pci_access_level() const
 {
-    auto value = lookup("pci_ecam"sv).value_or("on"sv);
-    if (value == "on"sv)
+    auto value = lookup("pci"sv).value_or("ecam"sv);
+    if (value == "ecam"sv)
         return PCIAccessLevel::MemoryAddressing;
-    if (value == "off"sv)
+    if (value == "io"sv)
         return PCIAccessLevel::IOAddressing;
+    if (value == "none"sv)
+        return PCIAccessLevel::None;
     PANIC("Unknown PCI ECAM setting: {}", value);
 }
 
+UNMAP_AFTER_INIT bool CommandLine::is_pci_disabled() const
+{
+    return lookup("pci"sv).value_or("ecam"sv) == "none"sv;
+}
+
 UNMAP_AFTER_INIT bool CommandLine::is_legacy_time_enabled() const
 {
     return lookup("time"sv).value_or("modern"sv) == "legacy"sv;

diff --git a/Kernel/CommandLine.h b/Kernel/CommandLine.h
@@ -31,6 +31,7 @@ enum class AcpiFeatureLevel {
 };
 
 enum class PCIAccessLevel {
+    None,
     IOAddressing,
     MemoryAddressing,
 };
@@ -70,6 +71,7 @@ class CommandLine {
     [[nodiscard]] bool is_physical_networking_disabled() const;
     [[nodiscard]] bool is_vmmouse_enabled() const;
     [[nodiscard]] PCIAccessLevel pci_access_level() const;
+    [[nodiscard]] bool is_pci_disabled() const;
     [[nodiscard]] bool is_legacy_time_enabled() const;
     [[nodiscard]] bool is_pc_speaker_enabled() const;
     [[nodiscard]] FrameBufferDevices are_framebuffer_devices_enabled() const;

@@ -38,21 +38,23 @@ UNMAP_AFTER_INIT AudioManagement::AudioManagement()
 
 UNMAP_AFTER_INIT void AudioManagement::enumerate_hardware_controllers()
 {
-    PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
-        // Note: Only consider PCI audio controllers
-        if (device_identifier.class_code().value() != to_underlying(PCI::ClassID::Multimedia)
-            || device_identifier.subclass_code().value() != to_underlying(PCI::Multimedia::SubclassID::AudioController))
-            return;
+    if (!PCI::Access::is_disabled()) {
+        PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
+            // Note: Only consider PCI audio controllers
+            if (device_identifier.class_code().value() != to_underlying(PCI::ClassID::Multimedia)
+                || device_identifier.subclass_code().value() != to_underlying(PCI::Multimedia::SubclassID::AudioController))
+                return;
 
-        dbgln("AC97: found audio controller at {}", device_identifier.address());
-        auto ac97_device = AC97::try_create(device_identifier);
-        if (ac97_device.is_error()) {
-            // FIXME: Propagate errors properly
-            dbgln("AudioManagement: failed to initialize AC97 device: {}", ac97_device.error());
-            return;
-        }
-        m_controllers_list.append(ac97_device.release_value());
-    });
+            dbgln("AC97: found audio controller at {}", device_identifier.address());
+            auto ac97_device = AC97::try_create(device_identifier);
+            if (ac97_device.is_error()) {
+                // FIXME: Propagate errors properly
+                dbgln("AudioManagement: failed to initialize AC97 device: {}", ac97_device.error());
+                return;
+            }
+            m_controllers_list.append(ac97_device.release_value());
+        });
+    }
 }
 
 UNMAP_AFTER_INIT void AudioManagement::enumerate_hardware_audio_channels()

diff --git a/Kernel/GlobalProcessExposed.cpp b/Kernel/GlobalProcessExposed.cpp
@@ -9,6 +9,7 @@
 #include <Kernel/Arch/x86/InterruptDisabler.h>
 #include <Kernel/Arch/x86/ProcessorInfo.h>
 #include <Kernel/Bus/PCI/API.h>
+#include <Kernel/Bus/PCI/Access.h>
 #include <Kernel/CommandLine.h>
 #include <Kernel/Devices/DeviceManagement.h>
 #include <Kernel/Devices/HID/HIDManagement.h>
@@ -949,6 +950,11 @@ UNMAP_AFTER_INIT ProcFSSystemDirectory::ProcFSSystemDirectory(const ProcFSRootDi
 {
 }
 
+UNMAP_AFTER_INIT void ProcFSRootDirectory::add_pci_node(Badge<PCI::Access>)
+{
+    m_components.append(ProcFSPCI::must_create());
+}
+
 UNMAP_AFTER_INIT NonnullRefPtr<ProcFSRootDirectory> ProcFSRootDirectory::must_create()
 {
     auto directory = adopt_ref(*new (nothrow) ProcFSRootDirectory);
@@ -961,7 +967,6 @@ UNMAP_AFTER_INIT NonnullRefPtr<ProcFSRootDirectory> ProcFSRootDirectory::must_cr
     directory->m_components.append(ProcFSDmesg::must_create());
     directory->m_components.append(ProcFSInterrupts::must_create());
     directory->m_components.append(ProcFSKeymap::must_create());
-    directory->m_components.append(ProcFSPCI::must_create());
     directory->m_components.append(ProcFSDevices::must_create());
     directory->m_components.append(ProcFSUptime::must_create());
     directory->m_components.append(ProcFSCommandLine::must_create());

diff --git a/Kernel/Graphics/GraphicsManagement.cpp b/Kernel/Graphics/GraphicsManagement.cpp
@@ -13,6 +13,8 @@
 #include <Kernel/Graphics/Console/BootFramebufferConsole.h>
 #include <Kernel/Graphics/GraphicsManagement.h>
 #include <Kernel/Graphics/Intel/NativeGraphicsAdapter.h>
+#include <Kernel/Graphics/VGA/ISAAdapter.h>
+#include <Kernel/Graphics/VGA/PCIAdapter.h>
 #include <Kernel/Graphics/VGACompatibleAdapter.h>
 #include <Kernel/Graphics/VirtIOGPU/GraphicsAdapter.h>
 #include <Kernel/Memory/AnonymousVMObject.h>
@@ -76,6 +78,16 @@ static inline bool is_display_controller_pci_device(PCI::DeviceIdentifier const&
     return device_identifier.class_code().value() == 0x3;
 }
 
+UNMAP_AFTER_INIT bool GraphicsManagement::determine_and_initialize_isa_graphics_device()
+{
+    dmesgln("Graphics: Using a ISA VGA compatible generic adapter");
+    auto adapter = ISAVGAAdapter::initialize();
+    m_graphics_devices.append(*adapter);
+    adapter->enable_consoles();
+    m_vga_adapter = adapter;
+    return true;
+}
+
 UNMAP_AFTER_INIT bool GraphicsManagement::determine_and_initialize_graphics_device(PCI::DeviceIdentifier const& device_identifier)
 {
     VERIFY(is_vga_compatible_pci_device(device_identifier) || is_display_controller_pci_device(device_identifier));
@@ -99,7 +111,7 @@ UNMAP_AFTER_INIT bool GraphicsManagement::determine_and_initialize_graphics_devi
             dmesgln("Graphics: The framebuffer set up by the bootloader is not RGB, ignoring fbdev argument");
         } else {
             dmesgln("Graphics: Using a preset resolution from the bootloader");
-            adapter = VGACompatibleAdapter::initialize_with_preset_resolution(device_identifier,
+            adapter = PCIVGACompatibleAdapter::initialize_with_preset_resolution(device_identifier,
                 multiboot_framebuffer_addr,
                 multiboot_framebuffer_width,
                 multiboot_framebuffer_height,
@@ -145,8 +157,8 @@ UNMAP_AFTER_INIT bool GraphicsManagement::determine_and_initialize_graphics_devi
             if (!m_vga_adapter && PCI::is_io_space_enabled(device_identifier.address())) {
                 create_bootloader_framebuffer_device();
             } else {
-                dmesgln("Graphics: Using a VGA compatible generic adapter");
-                adapter = VGACompatibleAdapter::initialize(device_identifier);
+                dmesgln("Graphics: Using a PCI VGA compatible generic adapter");
+                adapter = PCIVGACompatibleAdapter::initialize(device_identifier);
             }
             break;
         }
@@ -168,7 +180,7 @@ UNMAP_AFTER_INIT bool GraphicsManagement::determine_and_initialize_graphics_devi
 UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
 {
 
-    /* Explanation on the flow when not requesting to force not creating any 
+    /* Explanation on the flow when not requesting to force not creating any
      * framebuffer devices:
      * If the user wants to use a Console instead of the graphical environment,
      * they doesn't need to request text mode.
@@ -179,31 +191,41 @@ UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
      * 1. The bootloader didn't specify settings of a pre-set framebuffer. The
      * kernel has a native driver for a detected display adapter, therefore
      * the kernel can still set a framebuffer.
-     * 2. The bootloader specified settings of a pre-set framebuffer, and the 
+     * 2. The bootloader specified settings of a pre-set framebuffer, and the
      * kernel has a native driver for a detected display adapter, therefore
      * the kernel can still set a framebuffer and change the settings of it.
-     * In that situation, the kernel will simply ignore the Multiboot pre-set 
+     * In that situation, the kernel will simply ignore the Multiboot pre-set
      * framebuffer.
-     * 2. The bootloader specified settings of a pre-set framebuffer, and the 
-     * kernel does not have a native driver for a detected display adapter, 
+     * 2. The bootloader specified settings of a pre-set framebuffer, and the
+     * kernel does not have a native driver for a detected display adapter,
      * therefore the kernel will use the pre-set framebuffer. Modesetting is not
      * available in this situation.
-     * 3. The bootloader didn't specify settings of a pre-set framebuffer, and 
-     * the kernel does not have a native driver for a detected display adapter, 
+     * 3. The bootloader didn't specify settings of a pre-set framebuffer, and
+     * the kernel does not have a native driver for a detected display adapter,
      * therefore the kernel will try to initialize a VGA text mode console.
      * In that situation, the kernel will assume that VGA text mode was already
-     * initialized, but will still try to modeset it. No switching to graphical 
+     * initialized, but will still try to modeset it. No switching to graphical
      * environment is allowed in this case.
-     * 
+     *
      * By default, the kernel assumes that no framebuffer was created until it
-     * was proven that there's an existing framebuffer or we can modeset the 
+     * was proven that there's an existing framebuffer or we can modeset the
      * screen resolution to create a framebuffer.
-     * 
+     *
+     * Special cases:
+     * 1. If the user disabled PCI access, the kernel behaves like it's running
+     * on a pure ISA PC machine and therefore the kernel will try to initialize
+     * a variant that is suitable for ISA VGA handling, and not PCI adapters.
+     *
      * If the user requests to force no initialization of framebuffer devices
      * the same flow above will happen, except that no framebuffer device will
      * be created, so SystemServer will not try to initialize WindowServer.
      */
 
+    if (PCI::Access::is_disabled()) {
+        determine_and_initialize_isa_graphics_device();
+        return true;
+    }
+
     if (framebuffer_devices_console_only())
         dbgln("Forcing non-initialization of framebuffer devices (console only)");
     else if (framebuffer_devices_use_bootloader_framebuffer())

diff --git a/Kernel/Graphics/GraphicsManagement.h b/Kernel/Graphics/GraphicsManagement.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ * Copyright (c) 2021-2022, Liav A. <liavalb@hotmail.co.il>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -42,6 +42,7 @@ class GraphicsManagement {
 
 private:
     bool determine_and_initialize_graphics_device(PCI::DeviceIdentifier const&);
+    bool determine_and_initialize_isa_graphics_device();
     NonnullRefPtrVector<GenericGraphicsAdapter> m_graphics_devices;
     RefPtr<Graphics::Console> m_console;
 

diff --git a/Kernel/Graphics/Intel/NativeGraphicsAdapter.cpp b/Kernel/Graphics/Intel/NativeGraphicsAdapter.cpp
@@ -178,7 +178,7 @@ Optional<IntelNativeGraphicsAdapter::PLLSettings> IntelNativeGraphicsAdapter::cr
 }
 
 IntelNativeGraphicsAdapter::IntelNativeGraphicsAdapter(PCI::Address address)
-    : VGACompatibleAdapter(address)
+    : PCIVGACompatibleAdapter(address)
     , m_registers(PCI::get_BAR0(address) & 0xfffffffc)
     , m_framebuffer_addr(PCI::get_BAR2(address) & 0xfffffffc)
 {

diff --git a/Kernel/Graphics/Intel/NativeGraphicsAdapter.h b/Kernel/Graphics/Intel/NativeGraphicsAdapter.h
@@ -10,7 +10,7 @@
 #include <Kernel/Bus/PCI/Device.h>
 #include <Kernel/Graphics/Definitions.h>
 #include <Kernel/Graphics/FramebufferDevice.h>
-#include <Kernel/Graphics/VGACompatibleAdapter.h>
+#include <Kernel/Graphics/VGA/PCIAdapter.h>
 #include <Kernel/PhysicalAddress.h>
 #include <LibEDID/EDID.h>
 
@@ -47,7 +47,7 @@ enum RegisterIndex {
 }
 
 class IntelNativeGraphicsAdapter final
-    : public VGACompatibleAdapter {
+    : public PCIVGACompatibleAdapter {
 public:
     struct PLLSettings {
         bool is_valid() const { return (n != 0 && m1 != 0 && m2 != 0 && p1 != 0 && p2 != 0); }