ref: aa7ccb64d40cd0a8a7c629a9c1f85ff1907097cf
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;