mips64emul TODO
---------------

This file is a mess. Order is random. Don't trust it to be up-to-date.


	Caches / memory hierarchies:
		o)  src/coproc.c: bits in config registers should reflect
		    correct cache sizes for _all_ CPU types. (currently only
		    implemented for R4000, R1x000, and a few others)
		o)  src/memory.c: Implement correct cache emulation for
		    all CPU types. (currently only R2000/R3000 is implemented)
		    (per CPU, multiple levels should be possible,
		    associativity etc!)
		o)  R2000/R3000 isn't _100%_ correct, just almost correct :)
		o)  Move the -S (fill mem with random) functionality into the
		    memory.c subsystem, not machine.c or wherever it is now
		o)  ECC stuff, simulation of memory errors?  (Machine dependant)
		o)  More than 4GB of emulated RAM, when run on a 32-bit host?
		    (using manual swap-out of blocks to disk, ugly)
		o)  A global command line option should be used to turn
		    cache emulation on or off. When off, caches should be
		    faked like they are right now. When on, caches and
		    memory latencies should be emulated as correctly as
		    possible.

	Network layer:
		o)  see src/net.c

	Configure script:
		o)  Only enable Alpha prefetch on pca56 or higher, not on
		    ev4, ev5.
		o)  inet_ntoa detection on HP-UX is probably broken
		o)  Use getopts?
		o)  X11 libs and headers via command line option?
		o)  Verify that the configure script, building and running
		    the emulator works on some platforms:
			+)  Irix, AIX, QNX
			+)  MacOS X  (I've not tried this personally yet)
			+)  Ultrix using gcc? (Inside the emulator)

	Command line option parsing:
		o)  Use only one letter for selecting machine type (followed
		    by a substring of the machine type), not one letter
		    for each machine type as it is now.
		o)  Set endianness for raw binaries?
		o)  Long options?

	CPU Emulation:
		o)  Factor out the MIPS dependant parts of the cpu, so that
		    (in theory) the emulator could support other architectures
		    as well.   (sparc64?)
		o)  Binary translation:
			+)  recursive translation?
			+)  basic blocks instead of one-instruction? :)
			+)  on Alpha: don't assume pca56-like byte load/store?
			+)  write backend for UltraSparc and MIPS?
			+)  see src/bintrans.c for more info
		o)  Instructions:
			o)  Regression tests (see tests/README for more info):
				o)  Floating point exception handling, and
					add more instructions.
				o)  Finish the MIPS16 translator, and test it!
				o)  MIPS ISA I, II, III, IV
				o)  MIPS V (SIMD vector stuff?)
				o)  MDMX  (MIPS Digital Media Extension)
				o)  MIPS 3D
				o)  MIPS MT (Multi-thread stuff) (What's this?)
			o)  Warn about mis-used bit fields (ie bits that
			    should be all zeroes, warn about if they are not)!
			    Both for coprocessor registers and for instruction
			    opcodes.
			o)  the special2 stuff is a mess right now
			o)  warn and/or cause exceptions for unimplemented
			    instructions (depending on CPU type)
		o)  R2000/R3000:
			x)  R3000 "tri-byte stores". (What's this?)
		o)  R4000 and others:
			x)  watchhi/watchlo exceptions, and other exception
			    handling details
		o)  R10000 and others:  (R12000, R14000 ?)
			x)  memory space, exceptions, ...
			x)  use cop0 framemask for tlb lookups
			    (http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi/hdwr/bks/SGI_Developer/books/R10K_UM/sgi_html/t5.Ver.2.0.book_284.html)
		o)  Implement load delays?  Warnings on interlocks.
		o)  Implement all coprocessor 0 bits / functions.
			x)  coproc 0 selectors! (R4000 ?)
		o)  R4300 (nintendo64, no mmu?), R5900 (playstation2, weird
			TLB/cache? 128-bit GPRs, new instructions),
			4K (note: NOT R4000), 5K (note: NOT R5000),
			R6000 (ISA II), R8000
		o)  Multi-cpu stuff:
			+)  SGI's NUMA architecture. Study
				x)  Linux sources
				x)  SGI's specs on NUMA address space
			+)  Ultrix?  NetBSD doesn't do SMP on MIPS yet :-(
			+)  Own experiments with ycx2.

	Emulation of specific machines and devices:
		o)  Various SCSI and IDE controllers
		o)  PS/2-style keyboard controller (for several machines)
		o)  Generic busses;
			x)  PCI:  i/o and interrupts
			x)  QBus-22 (DECsystem 5500, 5400?)
		o)  DECstations (pmax):
			x)  ioasic
			x)  framebuffers:
				+)  better cursor support, overlays?,
				+)  2D/3D acceleration, PX[G]
			x)  status words / control words, make this more
				portable/cleaner
			x)  scsi controller(s): sii, DMA for asc
			x)  serial controllers: ssc, scc (and more work on dc?)
			x)  nvram on decstation 5000/125:  when using X11,
				set console=g or similar
			x)  DECstation 5840? "xbi-based SMP"
		o)  SGI and ARC machines (sgimips, arc):
			x)  more ARCBIOS stuff
			x)  Memory/interrupt controllers
			x)  Finish the SGI O2 framebuffer and keyboard support
			x)  IP30 (Linux with graphics support?)
			x)  IP32 ("O2"): mec (ethernet), scsi, ps2 kbd ...
			x)  SMP / NUMA?
		o)  Cobalt:  PCI and interrupt system, ethernet,
			harddisk controller(s)
		o)  Playstation 2:
			Hardware:  OHCI usb controller, keyboard, IDE, ...
			Has an R3000A as a subsystem (!)
		o)  hpcmips:  framebuffer(s) and harddisk controller,
			among other things
		o)  newsmips:
			o)  NetBSD/newsmips, get it to detect a "real"
			    model, right now everything is 100% bogus
		o)  Less interesting platforms:
			o)  mipsco? (NetBSD)
			o)  wgrisc? (big endian R3000, in OpenBSD's attic)
			o)  other embedded / evaluation MIPS boards
			o)  Playstation 1? R3000A. Weird hardware?
				No FPU, but something as coproc 2.
			o)  Nintendo 64, http://www.nintendo.com/systems/n64/n64_specs.jsp
				(R4300, 4MB RAM, really weird memory map)

	File/disk handling:
		o)  Read function argument count and types from binaries? (ELF?)
		o)  zlib support (should be optional) for:
			x)  loading gzipped kernels directly
			x)  (read-only) disk images (?)
		o)  ELF: separate LE/BE (MIPS instruction format) from LSB/MSB
			(ELF structure format)?
		o)  Better handling of tape files

	Userland ABI emulation:
		o)  see src/useremul.c

	Terminal based interactive debugger:
		o)  see src/debugger.c

	GUI, interactive debugger?  GTK+?  (The GUI _must be optional_!)
		o)  Breakpoints (complex expressions? combinations of register
			states, memory accesses and so on)
		o)  Instruction trace
		o)  Disassembly of RAM (_NOT_ the same as instruction trace)
		o)  Function call trace
		o)  Inspection of CPU registers/state, coprocessor
			registers/state, any device registers/state/contents
			o)  Framebuffers in windows / tabs.
			o)  Contents of RAM
		o)  "Start new emulation" should allow amount of
			RAM and nr of cpus to easily be specified.
			Multiple simultaneous machines should be possible.
		o)  Disk images.

	Regression tests:
		o)  see tests/

	Save state of the whole emulated machine, to be able to load it back
		in later?  (Memory, all device's states, all registers and
		so on.  Like taking a snapshot)

	Better X-windows functionality:
		o)  Mouse clicks can be "missed" in the current system;
			this is not good.
		o)  More 2D and 3D framebuffer acceleration
		o)  Non-resizable windows?  Or choose scaledown depending
			on size (and center the image, with a black border)
		o)  Different scaledown on different windows?
		o)  Switch scaledown during runtime? (Ala CTRL-ALT-plus/minus)
		o)  Keyboard and mouse events:
			x)  Do this for more machines than just DECstation
			x)  X11 cursor keycodes
			x)  Keys like CTRL, ALT, SHIFT do not get through
			    by themselves (these are necessary for example
			    to change the font of an xterm in X in the
			    emulator)
		o)  Generalize the framebuffer stuff by moving _ALL_ X11
			specific code to src/x11.c!

	Statistics:  (this could be interesting)
		o)  memory accesses (to measure cache efficiency and
			page coloring efficiency)
		o)  nr-of-instructions-in-a-row-that-don't-affect-eachother,
			and make histograms of this data
		o)  nr of simultaneous ASIDs in use in the TLB  (x = time)
		o)  position of read/write on (SCSI) disks   (x = time)

