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gerrit.openbmc.org / openbmc / obmc-console / 85055f997acddcf9d7ca49ed0981cb7700587b98
commit85055f997acddcf9d7ca49ed0981cb7700587b98[log] [tgz]
authorGeorge Liu <liuxiwei@ieisystem.com>Mon Aug 05 13:44:25 2024 +0800
committerAndrew Jeffery <andrew@codeconstruct.com.au>Fri Aug 09 07:52:07 2024 +0000
tree852649c3d88d7d77f4c5e36bda9b6712ffb178ee
parentce3688c90858864222d0efc543d05be675dbf776 [diff]
docs/mux-support.md: Fix MD014 warnings

The following warnings are generated by using markdownlint analysis:
```
MD014/commands-show-output Dollar signs used before commands without showing output [Context: "$ obmc-console-server --config..."]
```
Refer to markdown-lint [1] to fix MD014
[1]: https://github.com/updownpress/markdown-lint/blob/master/rules/014-commands-show-output.md

Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: I9daa0403355e45bf39410ccf92693bdccf1830c4
1 file changed
tree: 852649c3d88d7d77f4c5e36bda9b6712ffb178ee
  1. conf/
  2. docs/
  3. subprojects/
  4. test/
  5. .clang-format
  6. .clang-tidy
  7. .gitignore
  8. .travis.yml
  9. CHANGELOG.md
  10. config-internal.h
  11. config.c
  12. config.h
  13. console-client.c
  14. console-dbus.c
  15. console-mux.c
  16. console-mux.h
  17. console-server.c
  18. console-server.h
  19. console-socket.c
  20. LICENSE
  21. log-handler.c
  22. meson.build
  23. meson.options
  24. OWNERS
  25. README.md
  26. ringbuffer.c
  27. socket-handler.c
  28. tty-handler.c
  29. util.c
  30. util.h
README.md

obmc-console

To Build

To build this project, run the following shell commands:

meson setup build
meson compile -C build

To test:

dbus-run-session meson test -C build

To Run Server

Running the server requires a serial port (e.g. /dev/ttyS0):

touch obmc-console.conf
./obmc-console-server --config obmc-console.conf ttyS0

To Connect Client

To connect to the server, simply run the client:

./obmc-console-client

To disconnect the client, use the standard ~. combination.

Underlying design

This shows how the host UART connection is abstracted within the BMC as a Unix domain socket.

            +---------------------------------------------------------------------------------------------+
            |                                                                                             |
            |       obmc-console-client       unix domain socket         obmc-console-server              |
            |                                                                                             |
            |     +----------------------+                           +------------------------+           |
            |     |   client.2200.conf   |  +---------------------+  | server.ttyVUART0.conf  |           |
        +---+--+  +----------------------+  |                     |  +------------------------+  +--------+-------+
Network    | 2200 +-->                      +->+ @obmc-console.host0 +<-+                        <--+ /dev/ttyVUART0 |   UARTs
        +---+--+  | console-id = "host0" |  |                     |  |  console-id = "host0"  |  +--------+-------+
            |     |                      |  +---------------------+  |                        |           |
            |     +----------------------+                           +------------------------+           |
            |                                                                                             |
            |                                                                                             |
            |                                                                                             |
            +---------------------------------------------------------------------------------------------+

This supports multiple independent consoles. The console-id is a unique portion for the unix domain socket created by the obmc-console-server instance. The server needs to know this because it needs to know what to name the pipe; the client needs to know it as it needs to form the abstract socket name to which to connect.

Mux Support

In some hardware designs, multiple UARTS may be available behind a Mux. Please reference docs/mux-support.md in that case.

Sample Development Setup

For developing obmc-console, we can use pseudo terminals (pty's) in Linux.

The socat command will output names of 2 pty's, one of which is the master and the other one is the slave. The master pty can be used to emulate a UART.

$ socat -d -d pty,raw,echo=0,link=pty1 pty,raw,echo=0,link=pty2

$ obmc-console-server --console-id dev $(realpath pty2)

$ obmc-console-client -i dev

# this message should appear for the client
$ echo "hi" > pty1