i386_getdev
i386_getdev((void **)(&rootdev), rootdevname, NULL);
i386_getdev(NULL, kernelname, &kernelpath);
i386_getdev((void **)(&rootdev), rootdevname, NULL);
int i386_getdev(void **vdev, const char *devspec, const char **path);
archsw.arch_getdev = i386_getdev;