/[gxemul]/trunk/README
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Revision 28 - (hide annotations)
Mon Oct 8 16:20:26 2007 UTC (16 years, 6 months ago) by dpavlin
File size: 3281 byte(s) 
++ trunk/HISTORY	(local)
$Id: HISTORY,v 1.1298 2006/07/22 11:27:46 debug Exp $
20060626	Continuing on SPARC emulation (beginning on the 'save'
		instruction, register windows, etc).
20060629	Planning statistics gathering (new -s command line option),
		and renaming speed_tricks to allow_instruction_combinations.
20060630	Some minor manual page updates.
		Various cleanups.
		Implementing the -s command line option.
20060701	FINALLY found the bug which prevented Linux and Ultrix from
		running without the ugly hack in the R2000/R3000 cache isol
		code; it was the phystranslation hint array which was buggy.
		Removing the phystranslation hint code completely, for now.
20060702	Minor dyntrans cleanups; invalidation of physpages now only
		invalidate those parts of a page that have actually been
		translated. (32 parts per page.)
		Some MIPS non-R3000 speed fixes.
		Experimenting with MIPS instruction combination for some
		addiu+bne+sw loops, and sw+sw+sw.
		Adding support (again) for larger-than-4KB pages in MIPS tlbw*.
		Continuing on SPARC emulation: adding load/store instructions.
20060704	Fixing a virtual vs physical page shift bug in the new tlbw*
		implementation. Problem noticed by Jakub Jermar. (Many thanks.)
		Moving rfe and eret to cpu_mips_instr.c, since that is the
		only place that uses them nowadays.
20060705	Removing the BSD license from the "testmachine" include files,
		placing them in the public domain instead; this enables the
		testmachine stuff to be used from projects which are
		incompatible with the BSD license for some reason.
20060707	Adding instruction combinations for the R2000/R3000 L1
		I-cache invalidation code used by NetBSD/pmax 3.0, lui+addiu,
		various branches followed by addiu or nop, and jr ra followed
		by addiu. The time it takes to perform a full NetBSD/pmax R3000
		install on the laptop has dropped from 573 seconds to 539. :-)
20060708	Adding a framebuffer controller device (dev_fbctrl), which so
		far can be used to change the fb resolution during runtime, but
		in the future will also be useful for accelerated block fill/
		copy, and possibly also simplified character output.
		Adding an instruction combination for NetBSD/pmax' strlen.
20060709	Minor fixes: reading raw files in src/file.c wasn't memblock
		aligned, removing buggy multi_sw MIPS instruction combination,
		etc.
20060711	Adding a machine_qemu.c, which contains a "qemu_mips" machine.
		(It mimics QEMU's MIPS machine mode, so that a test kernel
		made for QEMU_MIPS also can run in GXemul... at least to some
		extent.)  Adding a short section about how to run this mode to
		doc/guestoses.html.
20060714	Misc. minor code cleanups.
20060715	Applying a patch which adds getchar() to promemul/yamon.c
		(from Oleksandr Tymoshenko).
		Adding yamon.h from NetBSD, and rewriting yamon.c to use it
		(instead of ugly hardcoded numbers) + some cleanup.
20060716	Found and fixed the bug which broke single-stepping of 64-bit
		programs between 0.4.0 and 0.4.0.1 (caused by too quick
		refactoring and no testing). Hopefully this fix will not
		break too many other things.
20060718	Continuing on the 8253 PIT; it now works with Linux/QEMU_MIPS.
		Re-adding the sw+sw+sw instr comb (the problem was that I had
		ignored endian issues); however, it doesn't seem to give any
		big performance gain.
20060720	Adding a dummy Transputer mode (T414, T800 etc) skeleton (only
		the 'j' and 'ldc' instructions are implemented so far). :-}
20060721	Adding gtreg.h from NetBSD, updating dev_gt.c to use it, plus
		misc. other updates to get Linux 2.6 for evbmips/malta working
		(thanks to Alec Voropay for the details).
		FINALLY found and fixed the bug which made tlbw* for non-R3000
		buggy; it was a reference count problem in the dyntrans core.
20060722	Testing stuff; things seem stable enough for a new release.

==============  RELEASE 0.4.1  ==============
1 dpavlin 28 Gavare's eXperimental Emulator -- GXemul 0.4.1
2     ==================================================
3 dpavlin 2
4 dpavlin 22 Copyright (C) 2003-2006 Anders Gavare.
5 dpavlin 2
6    
7 dpavlin 24 Overview -- What is GXemul?
8     -----------------------------
9 dpavlin 2
10 dpavlin 14 GXemul is an experimental instruction-level machine emulator. Several
11     emulation modes are available. In some modes, processors and surrounding
12 dpavlin 12 hardware components are emulated well enough to let unmodified operating
13     systems (e.g. NetBSD) run as if they were running on a real machine.
14 dpavlin 2
15 dpavlin 24 Processors (ARM, MIPS, PowerPC) are emulated using a kind of dynamic
16     translation system. Performance is somewhere between traditional
17     interpretation and recompilation into native code. However, the dynamic
18     translation system used in GXemul does not (currently) generate native
19     code, and thus does not require platform-specific back-ends. In plain
20     English, this means that the dyntrans system works on any host platform.
21 dpavlin 2
22 dpavlin 24 Possible uses of the emulator include:
23 dpavlin 12
24 dpavlin 24 o) educational purposes, e.g. to learn how to write code for MIPS
25 dpavlin 20
26 dpavlin 24 o) hobby operating system development; the emulator can be used as a
27     complement to testing your code on real hardware
28    
29     o) running guest operating systems in a "sandboxed" environment
30    
31     o) compiling your source code inside a guest operating system which you
32     otherwise would not have access to (e.g. various exotic ports of
33     NetBSD), to make sure that your source code is portable to those
34     platforms
35    
36     o) simulating (ethernet) networks of computers running various
37     operating systems, to study their interaction with each other
38    
39     o) debugging code in general
40    
41     Use your imagination :-)
42    
43    
44     GXemul's limitations
45     --------------------
46    
47     o) GXemul is not (in general) a cycle-accurate simulator, because it does
48     not simulate things smaller than an instruction. Pipe-line stalls,
49     instruction latency effects etc. are more or less completely ignored.
50    
51     o) Hardware devices have been implemented in an ad-hoc and as-needed
52     manner, usually only enough to fool certain guest operating systems
53     (e.g. NetBSD) that the hardware devices exist and function well
54     enough for those guest operating systems to use them.
55    
56     A consequence of this is that a machine mode may be implemented well
57     enough to run NetBSD for that machine mode, but other guest operating
58     systems may not run at all, or behave strangely.
59    
60    
61 dpavlin 2 Quick start
62     -----------
63    
64 dpavlin 4 To compile, type './configure' and then 'make'. This should work on most
65 dpavlin 28 Unix-like systems. If it does not, then please mail me a bug report.
66 dpavlin 2
67 dpavlin 24 You might want to experiment with various CC and CFLAGS environment
68     variable settings, to get optimum performance.
69    
70 dpavlin 10 If you are impatient, and want to try out running a guest operating system
71 dpavlin 22 inside GXemul, read this: doc/guestoses.html#netbsdcatsinstall
72 dpavlin 2
73 dpavlin 10 If you want to use GXemul for experimenting with code of your own,
74     then I suggest you compile a Hello World program according to the tips
75     listed here: doc/experiments.html#hello
76 dpavlin 2
77 dpavlin 10 Please read the rest of the documentation in the doc/ sub-directory for
78     more detailed information on how to use the emulator.
79    
80    
81 dpavlin 2 Feedback
82     --------
83    
84     If you have found GXemul useful in some way, or feel like sending me
85     comments or feedback in general, then mail me at anders(at)gavare.se.
86    
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