boot args
 -serial=1  enable serial console
 -s single mode (boothowto |= 2)
 -b no bootrc (boothowto |= 0x20000)
 -x skip extension validation with no OSBundleRequired set? (boothowto |= 0x100)
 -l turn_on_log_leaks
 -acc_debug debug IOAccessoryManager
 -srv ?
 -ncl ?
 -nbuf max_nbuf_headers
 -kmem setup_kmem
 -trace new_nkdbufs (default 0x30D40)
 -msgbuf=?
 -dcc 
 -nand-enable-reformat
 -nand-erase
 -brightness
 -force-usb-power
 -dpsm
 -wdt (watcdog)
 -nand-enable-adm
 -nand-override-timing
 -sdio-crc-panic
 -dma-disable
idle
 -jtag 
 -sleep_test
 
kdp
  -_panicd_ip=
  -_router_ip=
  -debug
   DB_KDP_BP_DIS |0x80 |Support old versions of gdb on newer     |
        |              |     |systems,             
??
  -initmcl
marvell
  -marvel-debug
  -marvell-feature-flags
  -marvell-inactivity-timeout
  -marvell-powersave-timeout