Big Endian

Library for pulling generic types (primitives, classes, structs, etc.) from byte collections (ex: array, list, etc.) with big-endian byte ordering.

Reading

The resulting type instance value can be returned as the function output:

T read<T>(in IEnumerable<byte> input, int offset = 0);

or be asigned by reference:

void read<T>(out T output, in IEnumerable<byte> input, int offset = 0)

Arrays of a single type T can be returned from the big-endian byte collection using the read_array function. The function will either return a new array of T instances:

T[] read_array<T>(in IEnumerable<byte> input, int length, int offset = 0)

or fill an existing array by reference:

void read_array<T>(in IEnumerable<byte> input, ref T[] output, int offset = 0)

Writing

Similar to the read operation, writing can either return a new byte[]

byte[] write<T>(T value) 

or write data to an existing array at a specific offset

void write<T>(T value, ref byte[] output, int offset = 0)

Type Size

This returns the size in bytes of a generic type 'T'

int size<T>(in T typedVal)

int size<T>()

Important Notes about C# classes and Structs

There are a few this to take into consideration trying to parse C# classes and structs from a byte array.

• C# structs do not support arrays of a defined size like C structs do.
• C# classes do not normally maintain the order of their properties in the order you list them. For these reasons I suggest you use define any classes you plan on reading in with this library as having an explicit layout.

Example:

Below is an example of a class used to read N64 ROM headers:

[StructLayout(LayoutKind.Explicit, Size = 0x40)]
public class ROMHeader
{
    [FieldOffset(0x00)] public byte init_state_1;
    [FieldOffset(0x01)] public byte init_state_2;
    [FieldOffset(0x02)] public byte init_state_3;
    [FieldOffset(0x03)] public byte init_state_4;
    [FieldOffset(0x04)] public uint clockRate;
    [FieldOffset(0x08)] public uint program_counter;
    [FieldOffset(0x0C)] public uint release_address;
    [FieldOffset(0x10)] public uint crc1;
    [FieldOffset(0x14)] public uint crc2;
    [FieldOffset(0x18)] public byte[] unknown_0x18_0x1F = new byte[0x08];
    [FieldOffset(0x20)] public char[] name = new char[0x14];
    [FieldOffset(0x34)] public uint unknown_0x34;
    [FieldOffset(0x38)] public uint media_format;
    [FieldOffset(0x3C)] public ushort cartidge_id;
    [FieldOffset(0x3E)] public byte country_code;
    [FieldOffset(0x3F)] public byte version;
}

using System;
using System.IO;
using BigEndian;

byte[] rom = File.ReadAllBytes("PATH/TO/N64/ROM.z64");
ROMHeader parsed_header = BigEndian.read<ROMHeader>(rom);