-@item memchar_read @var{device}
-@findex memchar_read
-Provide read interface for CirMemCharDriver. Read from char device
-'memory' and return the data.
-
-@var{size} is the size of data want to read from. Refer to unencoded
-size of the raw data, would adjust to the init size of the memchar
-if the requested size is larger than it.
+@item ringbuf_read @var{device}
+@findex ringbuf_read
+Read and print up to @var{size} bytes from ring buffer character
+device @var{device}.
+Certain non-printable characters are printed \uXXXX, where XXXX is the
+character code in hexadecimal. Character \ is printed \\.
+Bug: can screw up when the buffer contains invalid UTF-8 sequences,
+NUL characters, after the ring buffer lost data, and when reading
+stops because the size limit is reached.