Add PATA-IDE header

inc/driver/storage/ata.h

@@ -0,0 +1,137 @@
+#pragma once
+#include <driver/generic/device.h>
+
+/************************
+ *** Team Kitty, 2021 ***
+ ***     Chroma       ***
+ ***********************/
+
+namespace Device {
+
+    /**
+     * @brief An implementation of a generic Parallel ATA device driver.
+     * Handles managing the state of the drive, reading and writing data, etc.
+     * 
+     * ATA Devices are currently READ ONLY.
+     * Writing to ATA is currently a NO-OP.
+     */
+    class ATADevice : public GenericStorage {
+    public:
+
+        /***************************/
+        /*       DEFINITIONS       */
+        /***************************/
+
+        // Base addresses for port I/O.
+        enum ATAAddress {
+            PRIMARY = 0x1F0,
+            SECONDARY = 0x170,
+            PRIMARY_DCR = 0x3F6,
+            SECONDARY_DCR = 0x376
+        };
+
+        // Used by the IDENTIFY command to tell the OS what type of drive this is.
+        enum ATAType {
+            PRIMARY_MASTER = 1,
+            PRIMARY_SLAVE = 2,
+            SECONDARY_MASTER = 3,
+            SECONDARY_SLAVE = 4
+        };
+
+        // A sequential list of registers that can be referenced by adding to a base address.
+        enum ATARegister {
+            DATA,
+            ERROR_FEATURE,
+            SECTOR_COUNT,
+            LBA0,
+            LBA1,
+            LBA2,
+            SELECTOR,
+            COMMAND_STATUS,
+            SECTOR_COUNT_2,
+            LBA3,
+            LBA4,
+            LBA5,
+            CONTROL_STATUS,
+            DEVICE_ADDRESS
+        };
+
+        // The common data responses that a drive can respond with.
+        enum ATAData {
+            TYPE_MASTER = 0xA0,
+            TYPE_SLAVE = 0xB0,
+            STATE_BUSY = 0x80,
+            STATE_FAULT = 0x20,
+            STATE_DRQ = 0x8,
+            STATE_ERROR = 0x1
+        };
+
+        // The commands that we can send to the drive.
+        enum ATACommand {
+            IDENTIFY = 0xEC,
+            READ = 0x24
+        };
+
+        /***************************/
+        /*        FUNCTIONS        */
+        /***************************/
+
+        // Initialize the drive.
+        void Init();
+
+        // Does this system have an ATA connection?
+        static bool HasATA();
+
+
+        // Pause for the given amount of read cycles.
+        inline void Wait(uint8_t Cycles) {
+            for(uint8_t i = 0; i < Cycles; i++)
+                ATACommandRead(true, ATARegister::COMMAND_STATUS);
+        }
+
+        // Block until the drive returns data.
+        inline uint8_t Spinlock() {
+            uint8_t Status = ATACommandRead(true, ATARegister::COMMAND_STATUS);
+            while(Status & 0x80) {
+                Status = ATACommandRead(true, ATARegister::COMMAND_STATUS);
+                __asm__ __volatile__("pause");
+            }
+            return Status;
+        }
+
+        // Handle an incoming IRQ from the drive.
+        void HandleIRQ(size_t IRQID);
+
+        // Read data from the drive.
+        GenericStorage::Status Read(uint8_t* Data, size_t Length, size_t Start) override {
+            ReadData(Start, Length, Data);
+            return GenericStorage::Status::OKAY;
+        }
+
+        // NOT IMPLEMENTED. WILL OVERWRITE THE DATA BUFFER WITH THE CONTENTS OF THE DISK AT Start.
+        GenericStorage::Status Write(uint8_t* Data, size_t Length, size_t Start) override {
+            ReadData(Start, Length, Data);
+            return GenericStorage::Status::OKAY;
+        }
+
+        const char* GetName() const final {
+            return "PATA-IDE";
+        }
+
+    private:
+
+        // Used to reduce redundant Selections
+        ATAType SelectedDrive;
+
+        // Write data to the ATA command registers.
+        static void ATACommandWrite(bool Primary, uint16_t Register, uint16_t Data);
+        // Read a value from the ATA command register.
+        static uint16_t ATACommandRead(bool Primary, uint16_t Register);
+
+        // Read data from the drive into a buffer.
+        void ReadData(size_t Location, size_t Length, uint8_t* Buffer);
+
+        // Get the current status of the driver.
+        static bool GetStatus();
+    };
+};