ref: e8c07ef08e834c0be34bae4a6be019b6163aaf27
dir: /sys/src/cmd/vt/event.h/
#define BSIZE 4000
#define MOUSE 0
#define KBD 1
#define HOST 2
#define HOST_BLOCKED 1
#define KBD_BLOCKED 2
typedef struct IOEvent {
short key;
short size;
uchar data[BSIZE];
} IOEvent;