nexus s resistors
=================

 150K	UART cable
 dmesg	usb 5-2: new low speed USB device using uhci_hcd and address 2	
	usb 5-2: device descriptor read/64, error -7
 system UART

 121K	RID_TTY_CONVERTER
 dmesg	nothing
 system ?

 301K	RID_FM_BOOT_ON_USB (download mode, to use with heimdall)
 dmesg	cdc_acm 1-8:2.0: ttyACM0: USB ACM device
 system	USB

 619K	RID_FM_BOOT_ON_UART (no download mode but UART)
 dmesg	hub 1-0:1.0: unable to enumerate USB device on port 8
	usb 5-2: new low speed USB device using uhci_hcd and address 16
 system	CAR_DOCK