3.1.2 The magic fields of Multiboot2 header

‘magic’

The field ‘magic’ is the magic number identifying the header, which must be the hexadecimal value 0xE85250D6.

‘architecture’

The field ‘architecture’ specifies the Central Processing Unit Instruction Set Architecture. Since ‘magic’ isn’t a palindrome it already specifies the endianness ISAs differing only in endianness recieve the same ID. ‘0’ means 32-bit (protected) mode of i386. ‘4’ means 32-bit MIPS.

‘header_length’

The field ‘header_length’ specifies the Length of Multiboot2 header in bytes including magic fields.

‘checksum’

The field ‘checksum’ is a 32-bit unsigned value which, when added to the other magic fields (i.e. ‘magic’, ‘architecture’ and ‘header_length’), must have a 32-bit unsigned sum of zero.