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+                                    MUSASHI
+                                    =======
+
+                                  Version 4.10
+
+             A portable Motorola M680x0 processor emulation engine.
+            Copyright 1998-2002 Karl Stenerud.  All rights reserved.
+
+
+
+INTRODUCTION:
+------------
+
+Musashi is a Motorola 68000, 68010, 68EC020, 68020, 68EC030, 68030, 68EC040 and
+68040 emulator written in C.  This emulator was written with two goals in mind:
+portability and speed.
+
+The emulator is written to ANSI C89 specifications.  It also uses inline
+functions, which are C9X compliant.
+
+It has been successfully running in the MAME project (www.mame.net) for years
+and so has had time to mature.
+
+
+
+LICENSE AND COPYRIGHT:
+---------------------
+
+Copyright © 1998-2001 Karl Stenerud
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+
+
+AVAILABILITY:
+------------
+The latest version of this code can be obtained at:
+https://github.com/kstenerud/Musashi
+
+
+
+CONTACTING THE AUTHOR:
+---------------------
+I can be reached at kstenerud@gmail.com
+
+
+
+BASIC CONFIGURATION:
+-------------------
+The basic configuration will give you a standard 68000 that has sufficient
+functionality to work in a primitive environment.
+
+This setup assumes that you only have 1 device interrupting it, that the
+device will always request an autovectored interrupt, and it will always clear
+the interrupt before the interrupt service routine finishes (but could
+possibly re-assert the interrupt).
+You will have only one address space, no tracing, and no instruction prefetch.
+
+To implement the basic configuration:
+
+- Open m68kconf.h and verify that the settings for INLINE will work with your
+  compiler. (Currently set to "static __inline__", which works in gcc 2.9.
+  For C9X compliance, it should be "inline")
+
+- In your host program, implement the following functions:
+    unsigned int  m68k_read_memory_8(unsigned int address);
+    unsigned int  m68k_read_memory_16(unsigned int address);
+    unsigned int  m68k_read_memory_32(unsigned int address);
+    void m68k_write_memory_8(unsigned int address, unsigned int value);
+    void m68k_write_memory_16(unsigned int address, unsigned int value);
+    void m68k_write_memory_32(unsigned int address, unsigned int value);
+
+- In your host program, be sure to call m68k_pulse_reset() once before calling
+  any of the other functions as this initializes the core.
+
+- Use m68k_execute() to execute instructions and m68k_set_irq() to cause an
+  interrupt.
+
+
+
+ADDING PROPER INTERRUPT HANDLING:
+--------------------------------
+The interrupt handling in the basic configuration doesn't emulate the
+interrupt acknowledge phase of the CPU and automatically clears an interrupt
+request during interrupt processing.
+While this works for most systems, you may need more accurate interrupt
+handling.
+
+To add proper interrupt handling:
+
+- In m68kconf.h, set M68K_EMULATE_INT_ACK to OPT_SPECIFY_HANDLER
+
+- In m68kconf.h, set M68K_INT_ACK_CALLBACK(A) to your interrupt acknowledge
+  routine
+
+- Your interrupt acknowledge routine must return an interrupt vector,
+  M68K_INT_ACK_AUTOVECTOR, or M68K_INT_ACK_SPURIOUS.  most m68k
+  implementations just use autovectored interrupts.
+
+- When the interrupting device is satisfied, you must call m68k_set_irq(0) to
+  remove the interrupt request.
+
+
+
+MULTIPLE INTERRUPTS:
+-------------------
+The above system will work if you have only one device interrupting the CPU,
+but if you have more than one device, you must do a bit more.
+
+To add multiple interrupts:
+
+- You must make an interrupt arbitration device that will take the highest
+  priority interrupt and encode it onto the IRQ pins on the CPU.
+
+- The interrupt arbitration device should use m68k_set_irq() to set the
+  highest pending interrupt, or 0 for no interrupts pending.
+
+
+
+SEPARATE IMMEDIATE READS:
+------------------------
+You can write faster memory access functions if you know whether you are
+fetching from ROM or RAM.  Immediate reads are always from the program space
+(Always in ROM unless it is running self-modifying code).
+
+To enable separate immediate reads:
+
+- In m68kconf.h, turn on M68K_SEPARATE_READ_IMM.
+
+- In your host program, implement the following functions:
+    unsigned int  m68k_read_immediate_16(unsigned int address);
+    unsigned int  m68k_read_immediate_32(unsigned int address);
+
+    Now you also have the pcrelative stuff:
+    unsigned int  m68k_read_pcrelative_8(unsigned int address);
+    unsigned int  m68k_read_pcrelative_16(unsigned int address);
+    unsigned int  m68k_read_pcrelative_32(unsigned int address);
+
+- If you need to know the current PC (for banking and such), set
+  M68K_MONITOR_PC to OPT_SPECIFY_HANDLER, and set M68K_SET_PC_CALLBACK(A) to
+  your routine.
+
+- In the unlikely case where you need to emulate some PMMU in the immediate
+  reads and/or pcrealtive stuff, you'll need to explicitely call the
+  translation address mechanism from your user functions this way :
+
+    if (PMMU_ENABLED)
+        address = pmmu_translate_addr(address);
+
+  (this is handled automatically by normal memory accesses).
+
+ADDRESS SPACES:
+--------------
+Most systems will only implement one address space, placing ROM at the lower
+addresses and RAM at the higher.  However, there is the possibility that a
+system will implement ROM and RAM in the same address range, but in different
+address spaces.
+
+In this case, you might get away with assuming that immediate reads are in the
+program space and all other reads are in the data space, if it weren't for the
+fact that the exception vectors are fetched from the data space.  As a result,
+anyone implementing this kind of system will have to copy the vector table
+from ROM to RAM using pc-relative instructions.
+
+This makes things bad for emulation, because this means that a non-immediate
+read is not necessarily in the data space.
+The m68k deals with this by encoding the requested address space on the
+function code pins:
+
+                       FC
+    Address Space      210
+    ------------------ ---
+    USER DATA          001
+    USER PROGRAM       010
+    SUPERVISOR DATA    101
+    SUPERVISOR PROGRAM 110
+    CPU SPACE          111 <-- not emulated in this core since we emulate
+                               interrupt acknowledge in another way.
+
+To emulate the function code pins:
+
+- In m68kconf.h, set M68K_EMULATE_FC to OPT_SPECIFY_HANDLER and set
+  M68K_SET_FC_CALLBACK(A) to your function code handler function.
+
+- Your function code handler should select the proper address space for
+  subsequent calls to m68k_read_xx (and m68k_write_xx for 68010+).
+
+Note: immediate reads are always done from program space, so technically you
+      don't need to implement the separate immediate reads, although you could
+      gain more speed improvements leaving them in and doing some clever
+      programming.
+
+
+
+USING DIFFERENT CPU TYPES:
+-------------------------
+The default is to enable only the 68000 cpu type.  To change this, change the
+settings for M68K_EMULATE_010 etc in m68kconf.h.
+
+To set the CPU type you want to use:
+
+- Make sure it is enabled in m68kconf.h.  Current switches are:
+    M68K_EMULATE_010
+    M68K_EMULATE_EC020
+    M68K_EMULATE_020
+
+- In your host program, call m68k_set_cpu_type() and then call
+  m68k_pulse_reset().  Valid CPU types are:
+    M68K_CPU_TYPE_68000,
+    M68K_CPU_TYPE_68010,
+    M68K_CPU_TYPE_68EC020,
+    M68K_CPU_TYPE_68020,
+    M68K_CPU_TYPE_68EC030,
+    M68K_CPU_TYPE_68030,
+    M68K_CPU_TYPE_68EC040,
+    M68K_CPU_TYPE_68040,
+    M68K_CPU_TYPE_SCC68070 (which is a 68010 with a 32 bit data bus).
+
+CLOCK FREQUENCY:
+---------------
+In order to emulate the correct clock frequency, you will have to calculate
+how long it takes the emulation to execute a certain number of "cycles" and
+vary your calls to m68k_execute() accordingly.
+As well, it is a good idea to take away the CPU's timeslice when it writes to
+a memory-mapped port in order to give the device it wrote to a chance to
+react.
+
+You can use the functions m68k_cycles_run(), m68k_cycles_remaining(),
+m68k_modify_timeslice(), and m68k_end_timeslice() to do this.
+Try to use large cycle values in your calls to m68k_execute() since it will
+increase throughput.  You can always take away the timeslice later.
+
+
+
+MORE CORRECT EMULATION:
+----------------------
+You may need to enable these in order to properly emulate some of the more
+obscure functions of the m68k:
+
+- M68K_EMULATE_BKPT_ACK causes the CPU to call a breakpoint handler on a BKPT
+  instruction
+
+- M68K_EMULATE_TRACE causes the CPU to generate trace exceptions when the
+  trace bits are set
+
+- M68K_EMULATE_RESET causes the CPU to call a reset handler on a RESET
+  instruction.
+
+- M68K_EMULATE_PREFETCH emulates the 4-word instruction prefetch that is part
+  of the 68000/68010 (needed for Amiga emulation).
+  NOTE: if the CPU fetches a word or longword at an odd address when this
+  option is on, it will yield unpredictable results, which is why a real
+  68000 will generate an address error exception.
+
+- M68K_EMULATE_ADDRESS_ERROR will cause the CPU to generate address error
+  exceptions if it attempts to read a word or longword at an odd address.
+
+- call m68k_pulse_halt() to emulate the HALT pin.
+
+
+
+CONVENIENCE FUNCTIONS:
+---------------------
+These are in here for programmer convenience:
+
+- M68K_INSTRUCTION_HOOK lets you call a handler before each instruction.
+
+- M68K_LOG_ENABLE and M68K_LOG_1010_1111 lets you log illegal and A/F-line
+  instructions.
+
+
+
+MULTIPLE CPU EMULATION:
+----------------------
+The default is to use only one CPU.  To use more than one CPU in this core,
+there are some things to keep in mind:
+
+- To have different cpus call different functions, use OPT_ON instead of
+  OPT_SPECIFY_HANDLER, and use the m68k_set_xxx_callback() functions to set
+  your callback handlers on a per-cpu basis.
+
+- Be sure to call set_cpu_type() for each CPU you use.
+
+- Use m68k_set_context() and m68k_get_context() to switch to another CPU.
+
+
+
+LOAD AND SAVE CPU CONTEXTS FROM DISK:
+------------------------------------
+You can use them68k_load_context() and m68k_save_context() functions to load
+and save the CPU state to disk.
+
+
+
+GET/SET INFORMATION FROM THE CPU:
+--------------------------------
+You can use m68k_get_reg() and m68k_set_reg() to gain access to the internals
+of the CPU.
+
+
+
+EXAMPLE:
+-------
+
+The subdir example contains a full example (currently linux & Dos only).
+
+Compilation
+-----------
+
+You can use the default Makefile in Musashi's directory, it works like this :
+1st build m68kmake, which will build m68kops.c and m68kops.h based on the
+contents of m68k_in.c.
+Then compile m68kcpu.o and m68kops.o. Add m68kdasm.o if you want the
+disassemble functions. When linking this to your project you will need libm
+for the fpu emulation of the 68040.
+
+Using some custom m68kconf.h outside Musashi's directory
+--------------------------------------------------------
+
+It can be useful to keep an untouched musashi directory in a project (from
+git for example) and maintain a separate m68kconf.h specific to the
+project. For this, pass -DMUSASHI_CNF="mycustomconfig.h" to gcc (or whatever
+compiler you use). Notice that if you use an unix shell (or make which uses
+the shell to launch its commands), then you need to escape the quotes like
+this : -DMUSASHI_CNF=\"mycustomconfig.h\"
+