Print list of all connected sd-mux devices and exit. It takes optional --vendor --product arguments that allow to use other VENDOR and PRODUCT IDs then the default ones. The default value is 0x04e8:6001 which belongs to SAMSUNG Electronics Company. VENDOR and PRODUCT IDs are used to discover all connected sd-mux devices. This is very important in post production (sd-mux device) phase, before first use.

Print detailed information about selected device (--device-serial). Sample output of this command:

 VID:     0x04e8
 PID:     0x6001
 Release: 0x0600
 Bus Powered:  90 mA
 Manufacturer: SRPOL
 Product:      sd-mux
 Serial:       odroid_u3_1
 Checksum      : ea57
 Internal EEPROM
 PNP: 1
 Channel A has Mode UART VCP
 C0 Function: TXLED
 C1 Function: RXLED
 C2 Function: TXDEN
 C3 Function: PWREN
 C4 Function: SLEEP

Shape of this output depends on libftdi library so may change along with library changes.

Print current state of selected device. Example command with output:

$ sd-mux-ctrl --status --device-serial odroid_u3_1
USB connected to: DUT
SD connected to: DUT
$
Or:
$ sd-mux-ctrl --status --device-serial odroid_u3_1
Device not initialized!
$
when the device is not initialized after connecting to a host.

Print serial number of selected device. Use --device-id to select wanted device. This command outputs only serial number, without end of line. This command is useful actually only for scripts. Example command with output:

[sd-mux-ctrl-0.0.1]$ sudo sd-mux-ctrl --device-id=0 --show-serial
minnow_max_1[sd-mux-ctrl-0.0.1]$

Set serial number of selected device. Use --device-id or --device-serial to select wanted device. Following example changes device's serial number from AL018T40 to odroid_u3_1 :

[rpm]$ sudo sd-mux-ctrl --device-serial=AL018T40 --vendor=0x403 --set-serial=odroid_u3_1

--set-serial command does actually a little bit more than setting a serial number. It also writes new values of VENDOR ID, Product and Manufacturer. VENDOR ID (VID) is set to 0x04e8 (SAMSUNG Electronics Company), Product is set to sd-mux and Manufacturer is set to SRPOL which is a short name of Samsung R&D Poland.

Set connected device into well defined state. After powering up, sd-mux device is in random state. SD card and USB may be connected either to DUT or TS. SD card and USB are not tied together so one of them may be connected to DUT and the other one may be connected to TS. All combinations are possible. The most important thing here is power steering. As we use bistable, two-coil relay we have to make sure that in stable state both coils are disconnected from power. Unfortunately after connecting sd-mux to USB host, state of power control lines is unknown so we have to set them into correct one. Init command powers off DUT and connects USB and SD card to TS. Example:

[rpm]$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --init

Connect USB port and SD card to a DUT (Device Under Test) and power it on. After executing this command the DUT should start and load image from SD card mounted in the sd-mux device.

Note that some devices won't (re)start after execution of this command. This is caused by SD multiplexer chip. When SD is connected to TS then it is actually connected to USB SD card reader. The reader powers up SD card and some part of the voltage is transmitted to the DUT through SD mux chip. To force restart one must invoke --tick command after --dut is executed. Odroid U3 is an example of device with such behavior.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --dut
$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --tick

Connect USB port and SD card to a TS (Test Server) and powers off the DUT (Device Under Test). After executing this command SD card is connected to SD card reader at the TS side.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --ts

Set FTDI chip (FT245RL) pins to given state. --pins takes 8 bit word as an argument and optional --invert argument inverts all bits in the given word. This value, after optional inverting, is written to FT245RL D0-D7 pins.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --pins=0x69 --invert

Disconnect power from the Device Under Test and reconnect again after 1000 ms. If --tick-time is used, then 1000ms is replaced with number of milliseconds given in --tick-time argument.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --tick --tick-time=2000

Disconnect or connect terminals of dynamic jumper. Argument "on" connects and "off" disconnects the terminals.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --dyper1 on

Disconnect or connect terminals of dynamic jumper. Argument "on" connects and "off" disconnects the terminals.

$ sudo sd-mux-ctrl --device-serial=odroid_u3_1 --dyper2 on