filesystems/spufs/spufs.rst

10        spufs - the SPU file system
16        The SPU file system is used on PowerPC machines that implement the Cell
20        The file system provides a name space similar to posix shared memory or
21        message queues. Users that have write permissions on  the  file  system
45        the operations supported on regular file systems. This list details the
57        possible operations, e.g. read access on the wbox file.
64        accessed  like  a regular shared memory file and contains both code and
66        open mem file are:
71               file. The file size is the size of the local storage of the SPU,
81        The first SPU to CPU communication mailbox. This file is read-only  and
82        can  be  read  in  units of 32 bits.  The file can only be used in non-
84        operations on an open mbox file are:
95        The  second  SPU  to CPU communication mailbox. This file is similar to
96        the first mailbox file, but can be read in blocking I/O mode,  and  the
98        operations on an open ibox file are:
103               box and the file descriptor has been opened with O_NONBLOCK, the
106               If  there  is  no  data  available  in the mail box and the file
113               Poll  on  the  ibox  file returns (POLLIN | POLLRDNORM) whenever
121        operations  on  an open wbox file are: write(2) If a count smaller than
123        is  no space available in the mail box and the file descriptor has been
127        If  there is no space available in the mail box and the file descriptor
134               Poll  on  the  ibox file returns (POLLOUT | POLLWRNORM) whenever
143        operations on an open ``*box_stat`` file are:
174        spu_tag_mask, event_mask or srr0 file are:
179               subsequent reads from the same file descriptor  will  result  in
182               subsequent read operations will return zero bytes and a new file
186               A write operation on the file results in setting the register to
189               buffer.  Subsequent writes to the same file descriptor overwrite
194        This file gives access to the Floating Point Status and Control  Regis-
195        ter as a four byte long file. The operations on the fpcr file are:
214        space through the file.  After the value has been read by the  SPU,  it
216        nal2 file are:
232               file.
242        or signal2_type file are:
247               quent reads from the same file descriptor will  result  in  com-
249               subsequent read operations will return zero bytes and a new file
253               A write operation on the file results in setting the register to
256               buffer.  Subsequent writes to the same file descriptor overwrite