/// <summary>
/// Reads LDA data blocks
/// </summary>
/// <remarks>
/// The format of LDA blocks is:
/// +------+
/// | 0001 | - word16 - Magic
/// |------|
/// | BC | - word16 - Count
/// |------|
/// | ADDR | - word16 - Absolute load address
/// |------|
/// | Data | - byte[] - Data (`Count` bytes)
/// ...
/// |------|
/// | Chk | - byte - Checksum
/// +------+
/// </remarks>
/// <param name="rdr"></param>
/// <returns></returns>
public ImageSegment ReadDataBlock(LeImageReader rdr)
{
ushort w;
ushort count;
ushort uAddr;
byte b;
if (!rdr.TryReadLeUInt16(out w) || w != 0x0001)
return null;
if (!rdr.TryReadLeUInt16(out count))
return null;
if (!rdr.TryReadLeUInt16(out uAddr))
return null;
var data = rdr.ReadBytes(count);
if (data == null || data.Length < count)
return null;
if (!rdr.TryReadByte(out b))
return null;
Debug.Print("Data block: {0:X4} {1:X4}", uAddr, count);
return new ImageSegment(
string.Format("seg{0:X4}", uAddr),
new MemoryArea(Address.Ptr16(uAddr), data),
AccessMode.ReadWriteExecute);
}
