1 files changed, 131 insertions, 0 deletions
diff --git a/src/ata.hpp b/src/ata.hpp
new file mode 100644
index 0000000..5394c31
--- /dev/null
+++ b/src/ata.hpp
@@ -0,0 +1,131 @@
+#ifndef ATA_HPP
+#define ATA_HPP
+
+#include "portio.hpp"
+
+#include <cstdint>
+#include <utility>
+
+namespace ATA
+{
+    enum class Type {
+        None,
+        ATA,
+        ATAPI
+    };
+
+    enum class Base : std::uint16_t {
+        Primary = 0x01F0,
+        Secondary = 0x0170
+    };
+
+    enum class Drive : std::uint8_t {
+        Master = 0xA0,
+        Slave = 0xB0
+    };
+
+    enum class Command : std::uint8_t {
+        Identify = 0xEC,
+        IdentifyPacketDevice = 0xA1
+    };
+
+    namespace Status {
+        static constexpr std::uint8_t Busy  = 0x80;
+        static constexpr std::uint8_t Ready = 0x40;
+        static constexpr std::uint8_t DF    = 0x20;
+        static constexpr std::uint8_t DSC   = 0x10;
+        static constexpr std::uint8_t DRQ   = 0x08;
+        static constexpr std::uint8_t CORR  = 0x04;
+        static constexpr std::uint8_t Index = 0x02;
+        static constexpr std::uint8_t Error = 0x01;
+    }
+
+    static constexpr std::uint8_t ATAPIIdentify0 = 0x14;
+    static constexpr std::uint8_t ATAPIIdentify1 = 0xEB;
+
+    using enum Base;
+    using enum Drive;
+
+    template<Base PBase>
+    struct Bus
+    {
+        template<Base b, unsigned offs>
+        using BPort = Port<std::to_underlying(b) + offs>;
+
+        [[no_unique_address]] BPort<PBase, 0> data;
+        [[no_unique_address]] BPort<PBase, 1> errFeats;
+        [[no_unique_address]] BPort<PBase, 2> count;
+        [[no_unique_address]] BPort<PBase, 3> lba0;
+        [[no_unique_address]] BPort<PBase, 4> lba1;
+        [[no_unique_address]] BPort<PBase, 5> lba2;
+        [[no_unique_address]] BPort<PBase, 6> select;
+        [[no_unique_address]] BPort<PBase, 7> cmdStat;
+
+        Type identify(Drive drv) {
+            auto type = Type::None;
+
+            data = std::to_underlying(drv);
+            count = '\0';
+            lba0 = '\0';
+            lba1 = '\0';
+            lba2 = '\0';
+            cmdStat = std::to_underlying(Command::Identify);
+    
+            if (cmdStat == '\0')
+                return type;
+
+            type = Type::ATA;
+            while (cmdStat & Status::Busy);
+
+            std::uint8_t stat;
+            do {
+                stat = cmdStat;
+
+                if (stat & Status::Error) {
+                    if (lba1 == ATAPIIdentify0 && lba2 == ATAPIIdentify1) {
+                        type = identifyAtapi(drv);
+                        break;
+                    } else {
+                        return type;
+                    }
+                }
+            } while (!(stat & Status::DRQ));
+
+            if (type != Type::None) {
+                for (int i = 0; i < 256; ++i) {
+                    volatile std::uint16_t w = data;
+                    (void)w;
+                }
+            }
+
+            return type;
+        }
+
+        Type identifyAtapi(Drive drv) {
+            data = std::to_underlying(drv);
+            count = '\0';
+            lba0 = '\0';
+            lba1 = '\0';
+            lba2 = '\0';
+            cmdStat = std::to_underlying(Command::IdentifyPacketDevice);
+    
+            if (cmdStat == '\0')
+                return Type::None;
+
+            while (cmdStat & Status::Busy);
+
+            std::uint8_t stat;
+            do {
+                stat = cmdStat;
+
+                if (stat & Status::Error)
+                    return Type::None;
+            } while (!(stat & Status::DRQ));
+
+            return Type::ATAPI;
+        }
+    };
+} // ATA
+
+#endif // ATA_HPP
+