MD_FETCH
boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *) + PTOV_OFFSET;
ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
efi_systbl_phys = MD_FETCH(kmdp, MODINFOMD_FW_HANDLE, vm_paddr_t);