DDB

#include <ddb.h>

typedef struct DDB { //
    ULONG  DDB_phys_addr;      // Physical address of ddb
    ULONG  DDB_Next_DDB;       // next DDB on DVT_DDB chain
    ULONG  DDB_Next_DDB_init;  // next DDB on DVT_DDB_init chain
    ULONG  DDB_dcb_ptr;        // address of first DCB owned by this DDB
    UCHAR  DDB_number_buses;   // # of buses supported by the adapter
    UCHAR  DDB_ios_flags;      // IOS flags; see below
    USHORT DDB_sig;            // DDB signature; also padding
    PVOID  DDB_dvt;            // address of this DDB's DVT
    PVOID  DDB_devnode_ptr;    // address of devnode for device
    PVOID  DDB_reserved;       // reserved; must be zero
} DDB , *pDDB;

Contains information about the device data block.

DDB_ios_flags

Private flags for the IOS. Non-IOS components must treat these as read-only. Can be a combination of these values:

See also DCB, DVT