/[gxemul]/trunk/TODO
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
ViewVC logotype

Annotation of /trunk/TODO

Parent Directory Parent Directory | Revision Log Revision Log


Revision 30 - (hide annotations)
Mon Oct 8 16:20:40 2007 UTC (13 years ago) by dpavlin
File size: 17305 byte(s)
++ trunk/HISTORY	(local)
$Id: HISTORY,v 1.1325 2006/08/15 15:38:37 debug Exp $
20060723	More Transputer instructions (pfix, nfix, opr, mint, ldl, ldlp,
		eqc, rev, ajw, stl, stlf, sthf, sub, ldnl, ldnlp, ldpi, move,
		wcnt, add, bcnt).
		Adding more SPARC instructions (andcc, addcc, bl, rdpr).
		Progress on the igsfb framebuffer used by NetBSD/netwinder.
		Enabling 8-bit fills in dev_fb.
		NetBSD/netwinder 3.0.1 can now run from a disk image :-)
20060724	Cleanup/performance fix for 64-bit virtual translation table
		updates (by removing the "timestamp" stuff). A full NetBSD/pmax
		3.0.1 install for R4400 has dropped from 667 seconds to 584 :)
		Fixing the igsfb "almost vga" color (it is 24-bit, not 18-bit).
		Adding some MIPS instruction combinations (3*lw, and 3*addu).
		The 8048 keyboard now turns off interrupt enable between the
		KBR_ACK and the KBR_RSTDONE, to work better with Linux 2.6.
		Not causing PPC DEC interrupts if PPC_NO_DEC is set for a
		specific CPU; NetBSD/bebox gets slightly further than before.
		Adding some more SPARC instructions: branches, udiv.
20060725	Refreshing dev_pckbc.c a little.
		Cleanups for the SH emulation mode, and adding the first
		"compact" (16-bit) instructions: various simple movs, nop,
		shll, stc, or, ldc.
20060726	Adding dummy "pcn" (AMD PCnet NIC) PCI glue.
20060727	Various cleanups; removing stuff from cpu.h, such as
		running_translated (not really meaningful anymore), and
		page flags (breaking into the debugger clears all translations
		anyway).
		Minor MIPS instruction combination updates.
20060807	Expanding the 3*sw and 3*lw MIPS instruction combinations to
		work with 2* and 4* too, resulting in a minor performance gain.
		Implementing a usleep hack for the RM52xx/MIPS32/MIPS64 "wait"
		instruction (when emulating 1 cpu).
20060808	Experimenting with some more MIPS instruction combinations.
		Implementing support for showing a (hardcoded 12x22) text
		cursor in igsfb.
20060809	Simplifying the NetBSD/evbmips (Malta) install instructions
		somewhat (by using a NetBSD/pmax ramdisk install kernel).
20060812	Experimenting more with the MIPS 'wait' instruction.
		PCI configuration register writes can now be handled, which
		allow PCI IDE controllers to work with NetBSD/Malta 3.0.1 and
		NetBSD/cobalt 3.0.1. (Previously only NetBSD 2.1 worked.)
20060813	Updating dev_gt.c based on numbers from Alec Voropay, to enable
		Linux 2.6 to use PCI on Malta.
		Continuing on Algor interrupt stuff.
20060814	Adding support for routing ISA interrupts to two different
		interrupts, making it possible to run NetBSD/algor :-)
20060814-15	Testing for the release.

==============  RELEASE 0.4.2  ==============


1 dpavlin 30 $Id: TODO,v 1.343 2006/08/14 18:46:30 debug Exp $
2 dpavlin 2
3 dpavlin 22 Hm. This file is in random order, and not all parts of it are up-to-date.
4 dpavlin 20
5 dpavlin 30
6     Implementation:
7     x) ARM "wait"-like instruction.
8     x) CLOCK FRAMEWORK!
9     x) Mouse support for NetBSD/pmax 4.x!
10     x) See netwinder_reset() in NetBSD; the current "an internal error
11     occured" message after reboot/halt is too ugly.
12 dpavlin 28 x) 64-bit ranges in src/cpus/memory_mips_v2p.c
13     x) Revert the dyntrans page template experiment? Hm.
14     x) Refactor the cpu type detection/initialization/listing.
15 dpavlin 30 Macro, which can be used as long as the cpu definitions
16     contain a 'name'?
17 dpavlin 28 x) Testmachine includes:
18     + dev_fb block fill and copy
19     + dev_fb draw characters (from the built-in font)?
20     + dev_fb input device? mouse pointer coordinates and buttons
21     (allow changes in these to cause interrupts as well?)
22     + Redefine the halt() function so that it stops "sometimes
23     soon", i.e. usage in demo code should be:
24     for (;;) {
25     halt();
26     }
27     x) Continue on SPARC emulation
28     + Enable it in the configure script as soon as it can
29     run all the demo programs.
30     x) Continue on Alpha emulation (virtual memory, etc). Cleanup.
31 dpavlin 30 x) Nicer MIPS status bits in register dumps.
32 dpavlin 28 x) Alignment exceptions (MIPS, PPC, ARM?, ...)
33 dpavlin 30 x) Rewrite the networking stack; make OpenBSD work better as a guest
34     OS, fix the performance problems, make Linux work with DHCP, etc.
35     Support VDE (vde.sf.net)? Allow SLIP connections, possibly PPP,
36     in addition to ethernet?
37     x) Implement more ethernet NICs.
38     x) IOP (I2O) device?
39 dpavlin 28
40 dpavlin 30 Documentation:
41     x) "Install netbsd/pmax first" => only use the install kernel?
42     x) Rewrite the section about experimental devices, after the
43     framebuffer acceleration has been implemented, and demos
44     written. (Symbolic names instead of numbers; example
45     use cases, etc. Mention demo files that use the various
46     features?)
47     x) "a very simple linear framebuffer device (for graphics output)"
48     under "which machines does gxemul emulate" ==> better
49     description?
50     x) Better description on how to set up a cross compiler?
51     Example for MIPS64.
52    
53 dpavlin 28 Long-term design:
54     x) Instruction combination collisions? How to avoid easily...
55 dpavlin 30 x) Think about how to do both SHmedia and SHcompact in a reasonable
56     way!
57 dpavlin 28 o) Actually use the settings object, better debugger stuff, etc!
58     o) Debugger command for enabling/disabling instruction statistics
59     during runtime. machine.statistics = on|off
60     x) MAINBUS REDESIGN!
61 dpavlin 30 x) PCI redesign... I need to read up on how PCI actually works :)
62 dpavlin 28 x) Clock framework! Go through all clock devices, make sure they
63 dpavlin 24 return correct data, and run at correct speeds!
64 dpavlin 28 x) Dyntrans with valgrind-inspired memory checker. (In memory_rw,
65     it would be reasonably simple to add; in each individual fast
66     load/store routine = a lot more work, and it would become
67     kludgy very fast.)
68 dpavlin 24 x) Dyntrans with SMP... lots of work to be done here.
69     x) Dyntrans with cache emulation... lots of work here as well.
70 dpavlin 28 x) Reimplement the config file parser from scratch.
71 dpavlin 24
72 dpavlin 28 -------------------------------------------------------------------------------
73    
74     Simple Valgrind-like checks?
75     o) Mark every address with bits which tell whether or not the address
76     has been written to.
77     o) What should happen when programs are loaded? Text/data, bss (zero
78     filled). But stack space and heap is uninitialized.
79     o) Uninitialized local variables:
80     A load from a place on the stack which has not previously
81     been stored to => warning. Increasing the stack pointer using
82     any available means should reset the memory to uninitialized.
83     o) If calls to malloc() and free() can be intercepted:
84     o) Access to a memory area after free() => warning.
85     o) Memory returned by malloc() is marked as not-initialized.
86     o) Non-passive, but good to have: Change the argument
87     given to malloc, to return a slightly larger memory
88     area, i.e. margin_before + size + margin_after,
89     and return the pointer + margin_before.
90     Any access to the margin_before or _after space results
91     in warnings. (free() must be modified to free the
92     actually allocated address.)
93    
94 dpavlin 24 SMP:
95     o) dev_mp doesn't work well with dyntrans yet
96     o) In general, IPIs, CAS, LL/SC etc must be made to work with dyntrans
97    
98     MIPS:
99     +) Some more work on opcodes.
100 dpavlin 30 x) The "wait" instruction. How to implement this functionality?
101     (SMP, non-MIPS, interrupt correctness, host idling, ...)
102 dpavlin 24 x) MIPS64 revision 2.
103 dpavlin 28 o) Find out which actual CPUs implement the rev2 ISA!
104 dpavlin 24 x) _MAYBE_ TX79 and R5900 actually differ in their
105     opcodes? Check this carefully!
106     o) Dyntrans: Count register updates are probably not 100% correct yet.
107     o) Refactor code for performance and readability/maintainability.
108     o) DROTR32 and similar MIPS64 rev 2 instructions, which have
109     a rotation bit which differs from previous ISAs.
110     o) EI and DI instructions for MIPS64/32 rev 2. NOTE: These are
111     _NOT_ the same as for R5900!
112 dpavlin 28 o) (Re)implement 128-bit loads/stores for R5900.
113 dpavlin 24 o) R4000 and others:
114     x) watchhi/watchlo exceptions, and other exception
115     handling details
116     o) R10000 and others: (R12000, R14000 ?)
117     x) memory space, exceptions, ...
118     x) use cop0 framemask for tlb lookups
119     (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)
120    
121 dpavlin 14 Dyntrans:
122 dpavlin 28 x) Redesign/rethink the delay slot mechanism used for e.g. MIPS,
123     so that it caches a translation (that is, an instruction
124     word and the instr_call it was translated to the last
125     time), so that it doesn't need to do slow
126     to_be_translated for each end of page?
127     x) Program Counter statistics:
128     Per machine? What about SMP? All data to the same file?
129     A debugger command should be possible to use to enable/
130     disable statistics gathering.
131     Configuration file option!
132 dpavlin 24 x) Common fatal_abort() function, which drops into the debugger
133     without continuing.
134 dpavlin 22 x) INVALIDATION should cause translations in _all_ cpus to be
135     invalidated, e.g. on a write to a write-protected page
136     (containing code)
137     x) 16-bit encodings? (MIPS16, ARM Thumb, SH3, ...)
138 dpavlin 18 x) Lots of other stuff: see src/cpus/README_DYNTRANS
139 dpavlin 22 x) true recompilation backend? think carefully about this,
140     experiment in a separate project (not in GXemul)
141 dpavlin 28 o) First test would be to just implement a simple
142     instruction such as MIPS' addiu or lui, on AMD64
143     hosts...
144     x) Idle loop detection? (Depends on target.) Could be turned
145     into usleep(1) or similar on the host... except when doing
146     e.g. SMP emulation. Then it becomes trickier.
147 dpavlin 18
148 dpavlin 30 Transputer:
149     x) Implement support for Helios binaries.
150     x) Stack and register contents at startup?
151     x) Figure out how to boot an entire Helios distribution.
152     x) Implement all instructions. :)
153    
154 dpavlin 24 Alpha:
155     o) Virtual memory (tlbs etc)
156     o) Get {NetBSD,OpenBSD,Linux}/alpha booting. :)
157    
158     SPARC:
159 dpavlin 30 o) Load/stores to alternate address spaces!
160 dpavlin 24 o) Save/restore register windows etc!
161 dpavlin 30 o) Finish the subcc and addcc flag computation code.
162     o) Add more registers (floating point, control regs etc)
163 dpavlin 28 o) Disassemly of some more instructions?
164 dpavlin 24 o) Are sll etc 32-bit sign-extending or zero-extending?
165     o) Finish the GDB register stuff.
166 dpavlin 28 o) SPARC v8, v7 etc?
167 dpavlin 24
168     Debugger:
169     o) How does SMP debugging work? Does it simply use "threads"?
170     What if the guest OS (running on an emulated SMP machine)
171     has a usertask running, with userland threads?
172     o) Try to make the debugger more modular and, if possible, reentrant!
173     o) Remove the emul command? (But show network info if showing
174     machines?)
175     o) Generalize the expression evaluator. (debugger_expr.c?)
176     settable variables ("show nr of instructions on average")
177     emul[x] defaults to current emul
178     machine[x] defaults to current machine
179     cpu[x] defaults to currently focused cpu
180     registers cpu arch dependent (#-prefix)
181     symbols @-prefix
182     numeric constants decimal, hex, and octal ($-prefix)
183     boolean yes,no, true,false
184     operators (+ - * / % & | ^ !)
185     parentheses for grouping subexpressions
186     NOTE: the change from % to # for register prefix!
187     examples:
188     emul[0].machine[2].cpu[0].pc
189     machine[test2].cpu[1].ra = main
190     settings.show_trace_tree = yes
191    
192     Settings:
193     o) Remove a setting.
194     o) Read/write a setting given a name. (Read as
195     string and/or int64_t simultaneously?)
196 dpavlin 28 o) Warnings when exiting the emulator, if the
197     settings have not been removed exactly in
198     the same way as they were added? This would
199     improve code cleanliness in the long term.
200     (I.e. require a corresponding _destroy()
201     function for all _new functions... machine_
202     cpu_ etc.)
203 dpavlin 24
204     Help command should have subsections! One for "expressions",
205     mirrored in the documentation, but the internal help should
206     be the one that should be considered correct.
207     o) see src/debugger.c for more
208    
209     POWER/PowerPC:
210     x) PPC optimizations; instr combs
211 dpavlin 28 x) 64-bit stuff: either Linux on G5, or perhaps some hobbyist
212     version of AIX? (if there exists such a thing)
213 dpavlin 24 x) find and fix the bug which causes NetBSD/macppc to fail after
214     an install!
215     x) macppc: adb controller; keyboard (for framebuffer mode)
216     x) make OpenBSD/macppc work (PCI controller stuff)
217    
218     Algor:
219 dpavlin 30 PCI interrupts... needed or stuff like the tlp NIC?
220 dpavlin 24
221     ARM:
222     o) try to get netbsd/evbarm 3.x running (iq80321)
223     o) make the xscale counter registers (ccnt) work
224     o) make the ata controller usable for FreeBSD!
225     o) zaurus for openbsd...
226     o) debian/cats crashes because of unimplemented coproc stuff.
227     fix this?
228    
229     Cache simulation:
230 dpavlin 28 o) Command line flags for:
231     o) CPU endianness?
232     o) Cache sizes? (multiple levels)
233 dpavlin 24 o) Separate from the CPU concept, so that multi-core CPUs sharing
234     e.g. a L2 cache can be simulated (?)
235     o) Instruction cache emulation is easiest (if separate from the
236     data cache); similar hack as the S;I; hack in cpu_dyntrans.c.
237     NOTE: if the architecture has a delay slot, then an instruction
238     slot can actually be executed as 2 instructions.
239     o) Data cache emulation = harder; each arch's load/store routines
240     must include support? running one instruction at a time and
241     having a cpu-dependant lookup function for each instruction
242     is another option (easier to implement, but very very slow).
243    
244     Documentation:
245     o) machines, cpus, devices.
246     o) Automagic documentation generation:
247     x) REMEMBER that several machines/devices can be in
248     the same source file!
249     o) Try to rewrite the install instructions for those machines
250     that use 3MAX into using CATS? (To remove the need to a raw
251     ffs partition using up all of the disk image.)
252    
253 dpavlin 22 More generic out_of_memory error reporting, and check everywhere!
254     Causes: OpenBSD has low default limits for normal users.
255     Host is 32-bit? (32-bit hosts are limited to 4 GB or less
256     of userspace memory.)
257     You are actually low on RAM. (As trivial as this might sound,
258     Unix systems usually allow processes to allocate virtual
259     memory beyond the amount of RAM in the machine.)
260    
261     Breakpoints: 32-bit vs 64-bit sign extension for MIPS, warnings, etc.
262     Use the debugger's symbolic name stuff. (which will have to be
263     extended soon to support stuff like "2*x + symbol + y" etc. cool
264     stuff)
265    
266     The Device subsystem:
267     x) allow devices to be moved and/or changed in size (down to a
268     minimum size, etc, or up to a max size)
269     x) keep track of interrupts and busses? actually, allowing any device
270 dpavlin 24 to be a bus might be a nice idea.
271     x) turn interrupt controllers into devices? :-)
272 dpavlin 22 x) refactor various clocks/nvram/cmos into one device?
273    
274 dpavlin 24 Clocks:
275     x) General framework for automagic clock adjustment for _all_
276     kinds of clocks and timers. (Which should be possible to turn
277     off, of course, like the way DECstation emulation works now.)
278 dpavlin 22
279     PCI:
280 dpavlin 24 x) last write was ffffffff ==> fix this, it should be used
281     together with a mask to get the correct bits. also, not ALL
282     bits are size bits! (lowest 4 vs lowest 2?)
283 dpavlin 22 x) add support for address fixups
284     x) generalize the interrupt routing stuff (lines etc). this should
285     be per machine? or per bus, that's better
286 dpavlin 24 x) add a "pcn" NIC (AMD PCnet32 Lance 79c970 (PCI 1022:2000)),
287     could be useful for several machine modes (Malta, Algor, evbarm,
288     hp700?, macppc, etc.)
289 dpavlin 22
290     Network layer:
291     o) DHCP (for Debian and BSD installers :-)
292     o) increase performance
293     o) don't rely on NetBSD-ish usage
294     o) Multiple networks per emulation, and let different
295     NICs in machines connect to different networks.
296     o) many other issues: see src/net.c
297    
298     Busses:
299     o) Redesign the entire "mainbus" concept!
300     o) Busses should be placed in a hierarchical tree!
301     o) Easily configurable interrupt routing in SMP systems.
302     o) Specific clock/bus speeds, cpu speeds etc.
303     o) Synchronization over network? or at least in dyntrans within
304     one emulated machine
305     o) dev->bus: TurboChannel, PCMCIA, ADB?
306    
307     Config file parser:
308 dpavlin 24 o) Rewrite it from scratch!
309 dpavlin 22 o) Usage of any expression available through the debugger
310     o) Support for running debugger commands (like the -c
311     command line option)
312    
313     Floating point layer:
314     o) make it common enough to be used by _all_ emulation modes
315 dpavlin 24 o) implement more stuff
316 dpavlin 22 o) non-IEEE modes (i.e. x86)?
317    
318 dpavlin 14 Userland emulation:
319 dpavlin 22 x) Lots of stuff; freebsd and netbsd (and linux?) syscalls.
320 dpavlin 14 x) Dynamic linking? Hm.
321 dpavlin 12
322 dpavlin 22 Sound:
323     x) generic sound framework
324     x) add one or more sound cards as devices
325 dpavlin 12
326 dpavlin 24 ASC SCSI controller:
327     x) NetBSD/arc 2.0 uses the ASC controller in a way which GXemul
328     cannot yet handle. (NetBSD 1.6.2 works ok.) (Possibly a problem
329     in NetBSD itself, http://mail-index.netbsd.org/source-changes/
330     2005/11/06/0024.html suggests that.)
331    
332 dpavlin 22 Caches / memory hierarchies: (this is mostly MIPS-specific)
333     o) src/memory*.c: Implement correct cache emulation for
334     all CPU types. (currently only R2000/R3000 is implemented)
335 dpavlin 28 (per CPU, multiple levels should be possible, associativity etc!)
336 dpavlin 22 o) R2000/R3000 isn't _100%_ correct, just almost correct :)
337     o) Move the -S (fill mem with random) functionality into the
338     memory.c subsystem, not machine.c or wherever it is now
339     o) ECC stuff, simulation of memory errors? (Machine dependent)
340     o) More than 4GB of emulated RAM, when run on a 32-bit host?
341     (using manual swap-out of blocks to disk, ugly)
342     o) A global command line option should be used to turn
343     cache emulation on or off. When off, caches should be
344     faked like they are right now. When on, caches and
345     memory latencies should be emulated as correctly as
346     possible.
347 dpavlin 2
348 dpavlin 22 File/disk/symbol handling:
349 dpavlin 28 o) Remove some of the complexity in file format guessing, for
350     Ultrix kernels that are actually disk images?
351 dpavlin 22 o) Better handling of tape files
352     o) Read function argument count and types from binaries? (ELF?)
353 dpavlin 24 o) Better demangling of C++ names. Note: GNU's C++ differs from e.g.
354     Microsoft's C++, so multiple schemes must be possible. See
355     URL at top of src/symbol_demangle.c for more info.
356 dpavlin 2
357 dpavlin 22 Userland ABI emulation:
358     o) see src/useremul.c
359 dpavlin 12
360 dpavlin 22 Terminal/console:
361     o) allow emulated serial ports to be connected to the outside
362     world in a more generic way, or even to other emulated
363     machines(?)
364 dpavlin 2
365 dpavlin 22 Save state of the whole emulated machine, to be able to load it back
366     in later? (Memory, all device's states, all registers and
367     so on. Like taking a snapshot. (SimOS seems to do this,
368     according to its website.))
369 dpavlin 6
370 dpavlin 22 Better framebuffer and X-windows functionality:
371     o) -Yx sometimes causes crashes.
372     o) Simple device access to framebuffer_blockcopyfill() etc,
373     and text output (using the built-in fonts), for dev_fb.
374     o) CLEAN UP the ugly event code
375     o) Mouse clicks can be "missed" in the current system; this is
376     not good. They should be put on a stack of some kind.
377     o) More 2D and 3D framebuffer acceleration.
378     o) Non-resizable windows? Or choose scaledown depending
379     on size (and center the image, with a black border).
380     o) Different scaledown on different windows?
381     o) Switch scaledown during runtime? (Ala CTRL-ALT-plus/minus)
382 dpavlin 24 o) Bug reported by Elijah Rutschman on MacOS with weird
383     keys (F5 = cursor down?).
384 dpavlin 22 o) Keyboard and mouse events:
385     x) Do this for more machines than just DECstation
386     x) more X11 cursor keycodes
387     x) Keys like CTRL, ALT, SHIFT do not get through
388     by themselves (these are necessary for example
389     to change the font of an xterm in X in the
390     emulator)
391     o) Generalize the framebuffer stuff by moving _ALL_ X11
392     specific code to src/x11.c!
393 dpavlin 2
394 dpavlin 22 Statistics: (this could be interesting)
395     o) Save to file and show graphics. It should be possible to
396     run gxemul after a simulation to just show the graphics,
397     or convert to a .ppm or .tga or similar.
398     o) memory accesses (to measure cache efficiency and
399     page coloring efficiency)
400     o) nr of simultaneous ASIDs in use in the TLB, for MIPS
401     o) percentage of time spent in different "states", such as
402     running userland code, kernel code, or idling (for CPUs
403     that have such an instruction, or whenever the PC is
404     inside a specific idle-function (address range)).
405     Possible additional state (for example on R3000): caches
406     disabled.
407     o) position of read/write on (SCSI) disks
408 dpavlin 2

  ViewVC Help
Powered by ViewVC 1.1.26