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gerrit.openbmc.org / openbmc / obmc-console / 366651d9ef0e03f97b1e1d2b6188f2b452044d1c
commit366651d9ef0e03f97b1e1d2b6188f2b452044d1c[log] [tgz]
authorMarshall Zhan <marshall.zhan.wiwynn@gmail.com>Thu Aug 22 17:10:44 2024 +0800
committerMarshall Zhan <marshall.zhan.wiwynn@gmail.com>Fri Oct 04 11:25:37 2024 +0800
tree7a1f9594f1cf5b105ace3f150921abe4c1201bc7
parent6498f9fa9792ef0c14dab4aca3d38a674f6402cd [diff]
log-handler: Set the end of the file as the file size

The file descriptor is lost after system AC cycle.
The log file will grow indefinitely if the log recorded does not exceed
the maximum log size after each AC cycle.

Change-Id: If23d68b08817d54731dd6eff8a42e9eb476b6437
Fixes: 46d9ef298f2e ("Do not truncate log files after reboot")
Signed-off-by: Marshall Zhan <marshall.zhan.wiwynn@gmail.com>
4 files changed
tree: 7a1f9594f1cf5b105ace3f150921abe4c1201bc7
  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