Aaru/SCSI/Modes/01.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : 01.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes and encodes SCSI MODE PAGE 01h: Read-write error recovery page.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library is distributed in the hope that it will be useful, but
//     WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2018 Natalia Portillo
// ****************************************************************************/

using System.Text;

namespace DiscImageChef.Decoders.SCSI
{
    public static partial class Modes
    {
        #region Mode Page 0x01: Read-write error recovery page
        /// <summary>
        /// Disconnect-reconnect page
        /// Page code 0x01
        /// 12 bytes in SCSI-2, SBC-1, SBC-2
        /// </summary>
        public struct ModePage_01
        {
            /// <summary>
            /// Parameters can be saved
            /// </summary>
            public bool PS;
            /// <summary>
            /// Automatic Write Reallocation Enabled
            /// </summary>
            public bool AWRE;
            /// <summary>
            /// Automatic Read Reallocation Enabled
            /// </summary>
            public bool ARRE;
            /// <summary>
            /// Transfer block
            /// </summary>
            public bool TB;
            /// <summary>
            /// Read continuous
            /// </summary>
            public bool RC;
            /// <summary>
            /// Enable early recovery
            /// </summary>
            public bool EER;
            /// <summary>
            /// Post error reporting
            /// </summary>
            public bool PER;
            /// <summary>
            /// Disable transfer on error
            /// </summary>
            public bool DTE;
            /// <summary>
            /// Disable correction
            /// </summary>
            public bool DCR;
            /// <summary>
            /// How many times to retry a read operation
            /// </summary>
            public byte ReadRetryCount;
            /// <summary>
            /// How many bits of largest data burst error is maximum to apply error correction on it
            /// </summary>
            public byte CorrectionSpan;
            /// <summary>
            /// Offset to move the heads
            /// </summary>
            public sbyte HeadOffsetCount;
            /// <summary>
            /// Incremental position to which the recovered data strobe shall be adjusted
            /// </summary>
            public sbyte DataStrobeOffsetCount;
            /// <summary>
            /// How many times to retry a write operation
            /// </summary>
            public byte WriteRetryCount;
            /// <summary>
            /// Maximum time in ms to use in data error recovery procedures
            /// </summary>
            public ushort RecoveryTimeLimit;

            /// <summary>
            /// Logical block provisioning error reporting is enabled
            /// </summary>
            public bool LBPERE;
        }

        public static ModePage_01? DecodeModePage_01(byte[] pageResponse)
        {
            if((pageResponse?[0] & 0x40) == 0x40) return null;

            if((pageResponse?[0] & 0x3F) != 0x01) return null;

            if(pageResponse[1] + 2 != pageResponse.Length) return null;

            if(pageResponse.Length < 8) return null;

            ModePage_01 decoded = new ModePage_01();

            decoded.PS |= (pageResponse[0] & 0x80) == 0x80;
            decoded.AWRE |= (pageResponse[2] & 0x80) == 0x80;
            decoded.ARRE |= (pageResponse[2] & 0x40) == 0x40;
            decoded.TB |= (pageResponse[2] & 0x20) == 0x20;
            decoded.RC |= (pageResponse[2] & 0x10) == 0x10;
            decoded.EER |= (pageResponse[2] & 0x08) == 0x08;
            decoded.PER |= (pageResponse[2] & 0x04) == 0x04;
            decoded.DTE |= (pageResponse[2] & 0x02) == 0x02;
            decoded.DCR |= (pageResponse[2] & 0x01) == 0x01;

            decoded.ReadRetryCount = pageResponse[3];
            decoded.CorrectionSpan = pageResponse[4];
            decoded.HeadOffsetCount = (sbyte)pageResponse[5];
            decoded.DataStrobeOffsetCount = (sbyte)pageResponse[6];

            if(pageResponse.Length < 12) return decoded;

            decoded.WriteRetryCount = pageResponse[8];
            decoded.RecoveryTimeLimit = (ushort)((pageResponse[10] << 8) + pageResponse[11]);
            decoded.LBPERE |= (pageResponse[7] & 0x80) == 0x80;

            return decoded;
        }

        public static string PrettifyModePage_01(byte[] pageResponse)
        {
            return PrettifyModePage_01(DecodeModePage_01(pageResponse));
        }

        public static string PrettifyModePage_01(ModePage_01? modePage)
        {
            if(!modePage.HasValue) return null;

            ModePage_01 page = modePage.Value;
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("SCSI Read-write error recovery page:");

            if(page.PS) sb.AppendLine("\tParameters can be saved");

            if(page.AWRE) sb.AppendLine("\tAutomatic write reallocation is enabled");
            if(page.ARRE) sb.AppendLine("\tAutomatic read reallocation is enabled");
            if(page.TB)
                sb.AppendLine("\tData not recovered within limits shall be transferred back before a CHECK CONDITION");
            if(page.RC)
                sb.AppendLine("\tDrive will transfer the entire requested length without delaying to perform error recovery");
            if(page.EER) sb.AppendLine("\tDrive will use the most expedient form of error recovery first");
            if(page.PER) sb.AppendLine("\tDrive shall report recovered errors");
            if(page.DTE) sb.AppendLine("\tTransfer will be terminated upon error detection");
            if(page.DCR) sb.AppendLine("\tError correction is disabled");
            if(page.ReadRetryCount > 0)
                sb.AppendFormat("\tDrive will repeat read operations {0} times", page.ReadRetryCount).AppendLine();
            if(page.WriteRetryCount > 0)
                sb.AppendFormat("\tDrive will repeat write operations {0} times", page.WriteRetryCount).AppendLine();
            if(page.RecoveryTimeLimit > 0)
                sb.AppendFormat("\tDrive will employ a maximum of {0} ms to recover data", page.RecoveryTimeLimit)
                  .AppendLine();
            if(page.LBPERE) sb.AppendLine("Logical block provisioning error reporting is enabled");

            return sb.ToString();
        }
        #endregion Mode Page 0x01: Read-write error recovery page
    public static byte[] EncodeModePage_01(ModePage_01 page)
    {
        byte[] pg = new byte[8];

        pg[0] = 0x01;
        pg[1] = 6;

        if(page.PS) pg[0] += 0x80;
        if(page.AWRE) pg[2] += 0x80;
        if(page.ARRE) pg[2] += 0x40;
        if(page.TB) pg[2] += 0x20;
        if(page.RC) pg[2] += 0x10;
        if(page.EER) pg[2] += 0x08;
        if(page.PER) pg[2] += 0x04;
        if(page.DTE) pg[2] += 0x02;
        if(page.DCR) pg[2] += 0x01;

        pg[3] = page.ReadRetryCount;
        pg[4] = page.CorrectionSpan;
        pg[5] = (byte)page.HeadOffsetCount;
        pg[6] = (byte)page.DataStrobeOffsetCount;

        // This is from a newer version of SCSI unknown what happen for drives expecting an 8 byte page
        /*
        pg[8] = page.WriteRetryCount;
        if (page.LBPERE)
            pg[7] += 0x80;
        pg[10] = (byte)((page.RecoveryTimeLimit & 0xFF00) << 8);
        pg[11] = (byte)(page.RecoveryTimeLimit & 0xFF);*/

        return pg;
    }
    }
}