public static async Task <byte[]> BuildBlock(LoadSegBlock loadSegBlock)
{
if (loadSegBlock.Data.Length % 4 != 0)
{
throw new ArgumentException("Load seg block data must be dividable by 4", nameof(LoadSegBlock.Data));
}
var structureSize = 5 * 4;
var maxDataSize = 512 - structureSize;
if (loadSegBlock.Data.Length > maxDataSize)
{
throw new ArgumentException($"Load seg block data is larger than max data size {maxDataSize}",
nameof(LoadSegBlock.Data));
}
var blockStream = new MemoryStream(loadSegBlock.BlockBytes == null || loadSegBlock.BlockBytes.Length == 0
? new byte[structureSize + loadSegBlock.Data.Length]
: loadSegBlock.BlockBytes);
var size = (structureSize + loadSegBlock.Data.Length) / 4;
await blockStream.WriteAsciiString(BlockIdentifiers.LoadSegBlock);
await blockStream.WriteLittleEndianUInt32((uint)size); // size
// skip checksum, calculated when block is built
blockStream.Seek(4, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(loadSegBlock.HostId); // SCSI Target ID of host, not really used
await blockStream.WriteLittleEndianInt32(loadSegBlock
.NextLoadSegBlock); // Block number of the next PartitionBlock
await blockStream.WriteBytes(loadSegBlock.Data);
// calculate and update checksum
var blockBytes = blockStream.ToArray();
loadSegBlock.Checksum = await BlockHelper.UpdateChecksum(blockBytes, 8);
loadSegBlock.BlockBytes = blockBytes;
return(blockBytes);
}
public static void ResetLoadSegBlockPointers(LoadSegBlock loadSegBlock)
{
loadSegBlock.NextLoadSegBlock = 0;
}