B_PARTITIONMASK
part = (bootdev >> B_PARTITIONSHIFT) & B_PARTITIONMASK;
part = (bootdev >> B_PARTITIONSHIFT) & B_PARTITIONMASK;
part = (bootdev >> B_PARTITIONSHIFT) & B_PARTITIONMASK;
#define B_PARTITION(val) (((val) >> B_PARTITIONSHIFT) & B_PARTITIONMASK)