devcall(* dvcntl)(struct dentry *, int32, int32, int32)
devcall(* dvwrite)(struct dentry *, void *, uint32)
devcall(* dvclose)(struct dentry *)
devcall(* dvputc)(struct dentry *, char)
devcall(* dvinit)(struct dentry *)
devcall(* dvopen)(struct dentry *, char *, char *)
devcall(* dvgetc)(struct dentry *)
devcall(* dvread)(struct dentry *, void *, uint32)
devcall(* dvseek)(struct dentry *, int32)