The NIC register space is constructed from a linked list of register blocks. Each block starts with a header that contains type, version, and next header fields. Blocks must be DWORD aligned in the register space. All fields must be naturally aligned. All pointers in the register blocks are relative to the start of the region. The list is terminated with a next pointer of 0x00000000. See :numref:`tbl_rb_list` for a list of all currently-defined register blocks.
The type field consists of a vendor ID in the upper 16 bits, and the sub type in the lower 16 bits. Vendor ID 0x0000 is used for all standard register blocks used by Corundum. See :numref:`tbl_rb_list` for a list of all currently-defined register blocks.
The version field consists of four fields, major, minor, patch, and meta. Version numbers must be changed when backwards-incompatible changes are made to register blocks. See :numref:`tbl_rb_list` for a list of all currently-defined register blocks.
The next pointer field contains a block-relative offset to the start of the header of the next register block in the chain. A next pointer of 0x00000000 indicates the end of the chain.
