openbsd_bootdata
struct openbsd_bootdata obd __attribute__((section(".openbsd.bootdata")));
obd = (struct openbsd_bootdata *)(long)phdr.p_paddr;
obd->len = sizeof(struct openbsd_bootdata);
if (phdr.p_filesz < sizeof(struct openbsd_bootdata))
struct openbsd_bootdata *obd;