Kernel: Introduce the StorageManagement class

The StorageManagement class has 2 roles:
1. During boot, it should find all storage controllers in the machine,
and then determine what is the boot device.
2. Later on boot, it is a registrar of all storage controllers and
storage devices. Thus, it could be used to show information about these
devices when implemented.

This change allows the user to specify a boot driver other than /dev/hda
and if it's connected in the machine - it will boot.

Kernel/Storage/StorageManagement.cpp

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
+ * 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.
+ */
+
+#include <Kernel/Devices/BlockDevice.h>
+#include <Kernel/PCI/Access.h>
+#include <Kernel/Storage/IDEController.h>
+#include <Kernel/Storage/StorageManagement.h>
+
+namespace Kernel {
+
+static StorageManagement* s_the;
+
+StorageManagement::StorageManagement(String root_device, bool force_pio)
+    : m_controllers(enumerate_controllers(force_pio))
+    , m_boot_device(determine_boot_device(root_device))
+{
+}
+
+NonnullRefPtr<StorageDevice> StorageManagement::determine_boot_device(String root_device) const
+{
+    ASSERT(!m_controllers.is_empty());
+    if (!root_device.starts_with("/dev/hd")) {
+        klog() << "init_stage2: root filesystem must be on an hard drive";
+        Processor::halt();
+    }
+    auto drive_letter = root_device.substring(strlen("/dev/hd"), root_device.length() - strlen("/dev/hd"))[0];
+
+    if (drive_letter < 'a' || drive_letter > 'z') {
+        klog() << "init_stage2: root filesystem must be on an hard drive name";
+        Processor::halt();
+    }
+
+    size_t drive_index = (u8)drive_letter - (u8)'a';
+    auto devices = storage_devices();
+    if (drive_index >= devices.size()) {
+        klog() << "init_stage2: invalid selection of hard drive.";
+        Processor::halt();
+    }
+    return devices[drive_index];
+}
+
+NonnullRefPtrVector<StorageController> StorageManagement::enumerate_controllers(bool force_pio) const
+{
+    NonnullRefPtrVector<StorageController> controllers;
+    PCI::enumerate([&](const PCI::Address& address, PCI::ID) {
+        if (PCI::get_class(address) == 0x1 && PCI::get_subclass(address) == 0x1) {
+            controllers.append(IDEController::initialize(address, force_pio));
+        }
+    });
+    return controllers;
+}
+
+NonnullRefPtrVector<StorageDevice> StorageManagement::storage_devices() const
+{
+    NonnullRefPtrVector<StorageDevice> devices;
+    for (auto& controller : m_controllers) {
+        for (size_t index = 0; index < controller.devices_count(); index++) {
+            auto device = controller.device(index);
+            if (device.is_null())
+                continue;
+            devices.append(device.release_nonnull());
+        }
+    }
+    return devices;
+}
+
+bool StorageManagement::initialized()
+{
+    return (s_the != nullptr);
+}
+
+void StorageManagement::initialize(String root_device, bool force_pio)
+{
+    ASSERT(!StorageManagement::initialized());
+    s_the = new StorageManagement(root_device, force_pio);
+}
+
+StorageManagement& StorageManagement::the()
+{
+    return *s_the;
+}
+
+NonnullRefPtr<StorageDevice> StorageManagement::boot_device() const
+{
+    return m_boot_device;
+}
+NonnullRefPtrVector<StorageController> StorageManagement::ide_controllers() const
+{
+    NonnullRefPtrVector<StorageController> ide_controllers;
+    for (auto& controller : m_controllers) {
+        if (controller.type() == StorageController::Type::IDE)
+            ide_controllers.append(controller);
+    }
+    return ide_controllers;
+}
+
+}