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gerrit.openbmc.org / openbmc / obmc-console / 553cb663ad0b775777dc704f76bf5b46b72080be
commit553cb663ad0b775777dc704f76bf5b46b72080be[log] [tgz]
authorAndrew Jeffery <andrew@codeconstruct.com.au>Tue Jul 09 15:14:56 2024 +0930
committerAndrew Jeffery <andrew@codeconstruct.com.au>Tue Jul 09 17:57:17 2024 +0930
tree73ae6a841cb73af28fc9d123d6ca936596ac1a26
parent982090d9ea1d2f81572e4a783e17d1a8b3f35a71 [diff]
console-server: Define static sigint object as `volatile sig_atomic_t`

The C language defines that access to any other type, of static storage
duration, in a signal handler, yields undefined-behavior. Avoid the
problem given that compilers like to assume undefined behavior doesn't
occur.

Change-Id: I3cd37d7933c6c759aa52b11e3fdbecfe07e25981
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
1 file changed
tree: 73ae6a841cb73af28fc9d123d6ca936596ac1a26
  1. conf/
  2. test/
  3. .clang-format
  4. .clang-tidy
  5. .gitignore
  6. .travis.yml
  7. CHANGELOG.md
  8. config.c
  9. console-client.c
  10. console-dbus.c
  11. console-server.c
  12. console-server.h
  13. console-socket.c
  14. LICENSE
  15. log-handler.c
  16. meson.build
  17. meson.options
  18. OWNERS
  19. README.md
  20. ringbuffer.c
  21. socket-handler.c
  22. tty-handler.c
  23. util.c
README.md

To Build

To build this project, run the following shell commands:

meson setup build
meson compile -C build

To test:

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.