sandbox: Improve sandbox serial port keyboard interface
Implements the tstc() interface for the serial driver. Multiplexing
the console between the serial port and a keyboard uses a polling
method of checking if characters are available; this means that the
serial console must be non-blocking when attempting to read
characters.
Signed-off-by: Taylor Hutt <thutt@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 36637af..3e37c93 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -44,6 +44,14 @@
return read(fd, buf, count);
}
+ssize_t os_read_no_block(int fd, void *buf, size_t count)
+{
+ const int flags = fcntl(fd, F_GETFL, 0);
+
+ fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+ return os_read(fd, buf, count);
+}
+
ssize_t os_write(int fd, const void *buf, size_t count)
{
return write(fd, buf, count);