Tag: TYPE

The TYPE tag is a four byte little endian string that states what type of firmare image the payload is.

Tag Format

IMG3

Img3TypeTag {
   0  u32   magic     // 'EPYT' ('TYPE' in little endian)
   4  u32   fullSize  // including header and padding
   8  u32   size      // including padding
   C  u32   value
  10  u8[]  padding   // optional
}

Example Tag

The following tag is from the AppleLogo payload from the 10.0.1 (build 14A403) build for the iPad 4 (iPhone3,6).

Offset0123456789ABCDEFASCII
10455059542000000004000000 EPYT .......
206F676F6C000000000000000000000000ogol............
3000000000....
OffsetLengthExplanation
0x144magic: When interpreted in little endian order, these bytes give the string, TYPE.
0x184fullSize: This tag is 0x20 (32) bytes long.
0x1C4size: The actual payload (including padding) is 4 bytes long.
0x204value: The actual value of the tag. When interpreted in little endian order, this gives the ASCII string LOGO (indicating that it's an AppleLogo file).
0x2416padding

Known Values

The value (located at relative offset 0xC) specifies what payload is contained in this file. It is stored in little endian form, but presented in big endian; Reverse the four bytes to get the stored form. These are the known possible values, sorted by value: