Update 1.4.1 to 1.5
-------------------
  User-visible changes in version 1.5 (since version 1.4.1):

  * New features/improvements:

  * VMIPS now includes a basic direct-mapped cache simulation. The
    cache isolation and cache swap bits in the CP0 Status register are
    now honored.

  * The boot monitor distributed with VMIPS now sets up a dummy
    `argv[0]' value for the loaded program. Also, it halts by entering
    an infinite loop rather than attempting to execute a `break'
    instruction when it encounters an unexpected exception.

  * The setup assembly routine distributed with VMIPS has been made
    more TLB-friendly. Identity virtual-to-physical mappings for the
    first few pages of physical RAM are installed in the TLB at program
    start time.

  * When `-o excmsg' is on, TLB miss addresses will be printed to
    stderr.

  * When `-o ttydev=stdout' is specified, simulated program output
    will be sent to VMIPS's standard output, even if it is not a tty.

  * The interactor can now disassemble memory. Also, stepping in the
    interactor now prints the PC after each step.

  * VMIPS now supports more of the GDB remote serial protocol, in
    support of the GDB `info threads' and `detach' commands. The debug
    protocol TCP port is now configurable via the `-o debugport'
    option. Also, if something halts the program while the debugger
    interface is active, VMIPS will tell GDB that the program exited.

  * Bug fixes:

  * A bug was fixed in the debugger interface where disconnecting from
    the debugger socket could cause vmips to enter an infinite loop.

  * The interactor will refuse to dump raw memory words at
    non-word-aligned addresses.

  * The CP0 Cause register IP field is now recomputed whenever the
    register is read, rather than only when exceptions happen. This
    makes polling loops with interrupts disabled work correctly.

  * A bug was fixed in the DECstation-compatible clock device which was
    preventing some of its registers from being zeroed properly.

  * Some endianness bugs were fixed in the generic memory-mapped device
    code and in the DECstation-compatible serial device.

(mef)