cdba/protocol.md

CDBA protocol description

General stuff:

cdba operates over ssh

Client:

• ~/.ssh/config is effectively the 'real' config on the client side
• The connection is established by executing:

# serverbinaryname defaults to 'cdba-server'
/usr/bin/ssh user@server serverbinaryname

• ssh stdout receives messages and the client is expected to handle them instantly after receiving, until EOF
• ssh stderr receives status updates (blue text) and the client is expected to handle them instantly after receiving, until EOF

Server:

• The server enumerates all of the connected devices, based on a configuration file
• Client messages are received over stdin
• Messages are sent to the clients over stdout, until the connection is closed (or drops)
• The server opens a tty to the serial port on the device and forwards the output via MSG_CONSOLE

Supported messages

C - client | S - server

1 - MSG_SELECT_BOARD [C -> S]

data = string board name | len = sizeof(data)

Select the board to operate on.

Return [S]: Echo the command back with len = 0.

2 - MSG_CONSOLE [C <-> S]

data = string_buffer | len = sizeof(data) Send TTY I/O.

Return [C/S]: Echo the command back with len = sizeof(buf), data = buf.

3 - MSG_HARDRESET

<unused>

4 - MSG_POWER_ON [C -> S]

len = 0

Power on the board.

Return [S]: Echo the command back with len = 0.

5 - MSG_POWER_OFF [C -> S]

len = 0

Power off the board.

Return [S]: Echo the command back with len = 0.

6 - MSG_FASTBOOT_PRESENT [S -> C]

data = 0 / 1 | len = 1

Signal that the device is available over fastboot and ready to receive further commands. Return [C]: MSG_FASTBOOT_DOWNLOAD or MSG_FASTBOOT_CONTINUE with len = 0.

7 - MSG_FASTBOOT_DOWNLOAD [C -> S]

data = binary_chunk | len = sizeof(data)

Send binary data for fastboot.

Return [S]: Echo the command back with len = 0.

8 - MSG_FASTBOOT_BOOT

<unused>

9 - MSG_STATUS_UPDATE [C -> S]

TODO: json

Return:

10 - MSG_VBUS_ON [C -> S]

Enable USB VBUS going to the board.

Return [S]: None

11 - MSG_VBUS_OFF [C -> S]

Disable USB VBUS going to the board.

Return [S]: None

12 - MSG_FASTBOOT_REBOOT

<unused>

13 - MSG_SEND_BREAK [C -> S]

len = 0

Send a tcsendbreak to the board.

Return [S]: None

14 - MSG_LIST_DEVICES [C - > S]

len = 0

List the available boards.

Return [S]: Echo the command back NUM_DEVICES times with len = sizeof(buf), data = buf. Once done, echo the command back with len = 0.

15 - MSG_BOARD_INFO [C -> S]

data = string board name | len = sizeof(data)

Get the board description.

Return [S]: Echo the command back with len = sizeof(buf), data = buf.

16 - MSG_FASTBOOT_CONTINUE [C -> S]

len = 0

Send fastboot continue to the board.

Return [S]: Echo the command back with len = 0.