root / qemu-tech.texi @ 36bb244b
History | View | Annotate | Download (19.5 kB)
1 |
\input texinfo @c -*- texinfo -*- |
---|---|
2 |
@c %**start of header |
3 |
@setfilename qemu-tech.info |
4 |
@settitle QEMU Internals |
5 |
@exampleindent 0 |
6 |
@paragraphindent 0 |
7 |
@c %**end of header |
8 |
|
9 |
@iftex |
10 |
@titlepage |
11 |
@sp 7 |
12 |
@center @titlefont{QEMU Internals} |
13 |
@sp 3 |
14 |
@end titlepage |
15 |
@end iftex |
16 |
|
17 |
@ifnottex |
18 |
@node Top |
19 |
@top |
20 |
|
21 |
@menu |
22 |
* Introduction:: |
23 |
* QEMU Internals:: |
24 |
* Regression Tests:: |
25 |
* Index:: |
26 |
@end menu |
27 |
@end ifnottex |
28 |
|
29 |
@contents |
30 |
|
31 |
@node Introduction |
32 |
@chapter Introduction |
33 |
|
34 |
@menu |
35 |
* intro_features:: Features |
36 |
* intro_x86_emulation:: x86 emulation |
37 |
* intro_arm_emulation:: ARM emulation |
38 |
* intro_ppc_emulation:: PowerPC emulation |
39 |
* intro_sparc_emulation:: SPARC emulation |
40 |
@end menu |
41 |
|
42 |
@node intro_features |
43 |
@section Features |
44 |
|
45 |
QEMU is a FAST! processor emulator using a portable dynamic |
46 |
translator. |
47 |
|
48 |
QEMU has two operating modes: |
49 |
|
50 |
@itemize @minus |
51 |
|
52 |
@item |
53 |
Full system emulation. In this mode, QEMU emulates a full system |
54 |
(usually a PC), including a processor and various peripherals. It can |
55 |
be used to launch an different Operating System without rebooting the |
56 |
PC or to debug system code. |
57 |
|
58 |
@item |
59 |
User mode emulation (Linux host only). In this mode, QEMU can launch |
60 |
Linux processes compiled for one CPU on another CPU. It can be used to |
61 |
launch the Wine Windows API emulator (@url{http://www.winehq.org}) or |
62 |
to ease cross-compilation and cross-debugging. |
63 |
|
64 |
@end itemize |
65 |
|
66 |
As QEMU requires no host kernel driver to run, it is very safe and |
67 |
easy to use. |
68 |
|
69 |
QEMU generic features: |
70 |
|
71 |
@itemize |
72 |
|
73 |
@item User space only or full system emulation. |
74 |
|
75 |
@item Using dynamic translation to native code for reasonable speed. |
76 |
|
77 |
@item Working on x86 and PowerPC hosts. Being tested on ARM, Sparc32, Alpha and S390. |
78 |
|
79 |
@item Self-modifying code support. |
80 |
|
81 |
@item Precise exceptions support. |
82 |
|
83 |
@item The virtual CPU is a library (@code{libqemu}) which can be used |
84 |
in other projects (look at @file{qemu/tests/qruncom.c} to have an |
85 |
example of user mode @code{libqemu} usage). |
86 |
|
87 |
@end itemize |
88 |
|
89 |
QEMU user mode emulation features: |
90 |
@itemize |
91 |
@item Generic Linux system call converter, including most ioctls. |
92 |
|
93 |
@item clone() emulation using native CPU clone() to use Linux scheduler for threads. |
94 |
|
95 |
@item Accurate signal handling by remapping host signals to target signals. |
96 |
@end itemize |
97 |
|
98 |
QEMU full system emulation features: |
99 |
@itemize |
100 |
@item QEMU can either use a full software MMU for maximum portability or use the host system call mmap() to simulate the target MMU. |
101 |
@end itemize |
102 |
|
103 |
@node intro_x86_emulation |
104 |
@section x86 emulation |
105 |
|
106 |
QEMU x86 target features: |
107 |
|
108 |
@itemize |
109 |
|
110 |
@item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation. |
111 |
LDT/GDT and IDT are emulated. VM86 mode is also supported to run DOSEMU. |
112 |
|
113 |
@item Support of host page sizes bigger than 4KB in user mode emulation. |
114 |
|
115 |
@item QEMU can emulate itself on x86. |
116 |
|
117 |
@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}. |
118 |
It can be used to test other x86 virtual CPUs. |
119 |
|
120 |
@end itemize |
121 |
|
122 |
Current QEMU limitations: |
123 |
|
124 |
@itemize |
125 |
|
126 |
@item No SSE/MMX support (yet). |
127 |
|
128 |
@item No x86-64 support. |
129 |
|
130 |
@item IPC syscalls are missing. |
131 |
|
132 |
@item The x86 segment limits and access rights are not tested at every |
133 |
memory access (yet). Hopefully, very few OSes seem to rely on that for |
134 |
normal use. |
135 |
|
136 |
@item On non x86 host CPUs, @code{double}s are used instead of the non standard |
137 |
10 byte @code{long double}s of x86 for floating point emulation to get |
138 |
maximum performances. |
139 |
|
140 |
@end itemize |
141 |
|
142 |
@node intro_arm_emulation |
143 |
@section ARM emulation |
144 |
|
145 |
@itemize |
146 |
|
147 |
@item Full ARM 7 user emulation. |
148 |
|
149 |
@item NWFPE FPU support included in user Linux emulation. |
150 |
|
151 |
@item Can run most ARM Linux binaries. |
152 |
|
153 |
@end itemize |
154 |
|
155 |
@node intro_ppc_emulation |
156 |
@section PowerPC emulation |
157 |
|
158 |
@itemize |
159 |
|
160 |
@item Full PowerPC 32 bit emulation, including privileged instructions, |
161 |
FPU and MMU. |
162 |
|
163 |
@item Can run most PowerPC Linux binaries. |
164 |
|
165 |
@end itemize |
166 |
|
167 |
@node intro_sparc_emulation |
168 |
@section SPARC emulation |
169 |
|
170 |
@itemize |
171 |
|
172 |
@item Somewhat complete SPARC V8 emulation, including privileged |
173 |
instructions, FPU and MMU. SPARC V9 emulation includes most privileged |
174 |
instructions, FPU and I/D MMU, but misses VIS instructions. |
175 |
|
176 |
@item Can run some 32-bit SPARC Linux binaries. |
177 |
|
178 |
@end itemize |
179 |
|
180 |
Current QEMU limitations: |
181 |
|
182 |
@itemize |
183 |
|
184 |
@item IPC syscalls are missing. |
185 |
|
186 |
@item 128-bit floating point operations are not supported, though none of the |
187 |
real CPUs implement them either. FCMPE[SD] are not correctly |
188 |
implemented. Floating point exception support is untested. |
189 |
|
190 |
@item Alignment is not enforced at all. |
191 |
|
192 |
@item Atomic instructions are not correctly implemented. |
193 |
|
194 |
@item Sparc64 emulators are not usable for anything yet. |
195 |
|
196 |
@end itemize |
197 |
|
198 |
@node QEMU Internals |
199 |
@chapter QEMU Internals |
200 |
|
201 |
@menu |
202 |
* QEMU compared to other emulators:: |
203 |
* Portable dynamic translation:: |
204 |
* Register allocation:: |
205 |
* Condition code optimisations:: |
206 |
* CPU state optimisations:: |
207 |
* Translation cache:: |
208 |
* Direct block chaining:: |
209 |
* Self-modifying code and translated code invalidation:: |
210 |
* Exception support:: |
211 |
* MMU emulation:: |
212 |
* Hardware interrupts:: |
213 |
* User emulation specific details:: |
214 |
* Bibliography:: |
215 |
@end menu |
216 |
|
217 |
@node QEMU compared to other emulators |
218 |
@section QEMU compared to other emulators |
219 |
|
220 |
Like bochs [3], QEMU emulates an x86 CPU. But QEMU is much faster than |
221 |
bochs as it uses dynamic compilation. Bochs is closely tied to x86 PC |
222 |
emulation while QEMU can emulate several processors. |
223 |
|
224 |
Like Valgrind [2], QEMU does user space emulation and dynamic |
225 |
translation. Valgrind is mainly a memory debugger while QEMU has no |
226 |
support for it (QEMU could be used to detect out of bound memory |
227 |
accesses as Valgrind, but it has no support to track uninitialised data |
228 |
as Valgrind does). The Valgrind dynamic translator generates better code |
229 |
than QEMU (in particular it does register allocation) but it is closely |
230 |
tied to an x86 host and target and has no support for precise exceptions |
231 |
and system emulation. |
232 |
|
233 |
EM86 [4] is the closest project to user space QEMU (and QEMU still uses |
234 |
some of its code, in particular the ELF file loader). EM86 was limited |
235 |
to an alpha host and used a proprietary and slow interpreter (the |
236 |
interpreter part of the FX!32 Digital Win32 code translator [5]). |
237 |
|
238 |
TWIN [6] is a Windows API emulator like Wine. It is less accurate than |
239 |
Wine but includes a protected mode x86 interpreter to launch x86 Windows |
240 |
executables. Such an approach has greater potential because most of the |
241 |
Windows API is executed natively but it is far more difficult to develop |
242 |
because all the data structures and function parameters exchanged |
243 |
between the API and the x86 code must be converted. |
244 |
|
245 |
User mode Linux [7] was the only solution before QEMU to launch a |
246 |
Linux kernel as a process while not needing any host kernel |
247 |
patches. However, user mode Linux requires heavy kernel patches while |
248 |
QEMU accepts unpatched Linux kernels. The price to pay is that QEMU is |
249 |
slower. |
250 |
|
251 |
The new Plex86 [8] PC virtualizer is done in the same spirit as the |
252 |
qemu-fast system emulator. It requires a patched Linux kernel to work |
253 |
(you cannot launch the same kernel on your PC), but the patches are |
254 |
really small. As it is a PC virtualizer (no emulation is done except |
255 |
for some priveledged instructions), it has the potential of being |
256 |
faster than QEMU. The downside is that a complicated (and potentially |
257 |
unsafe) host kernel patch is needed. |
258 |
|
259 |
The commercial PC Virtualizers (VMWare [9], VirtualPC [10], TwoOStwo |
260 |
[11]) are faster than QEMU, but they all need specific, proprietary |
261 |
and potentially unsafe host drivers. Moreover, they are unable to |
262 |
provide cycle exact simulation as an emulator can. |
263 |
|
264 |
@node Portable dynamic translation |
265 |
@section Portable dynamic translation |
266 |
|
267 |
QEMU is a dynamic translator. When it first encounters a piece of code, |
268 |
it converts it to the host instruction set. Usually dynamic translators |
269 |
are very complicated and highly CPU dependent. QEMU uses some tricks |
270 |
which make it relatively easily portable and simple while achieving good |
271 |
performances. |
272 |
|
273 |
The basic idea is to split every x86 instruction into fewer simpler |
274 |
instructions. Each simple instruction is implemented by a piece of C |
275 |
code (see @file{target-i386/op.c}). Then a compile time tool |
276 |
(@file{dyngen}) takes the corresponding object file (@file{op.o}) |
277 |
to generate a dynamic code generator which concatenates the simple |
278 |
instructions to build a function (see @file{op.h:dyngen_code()}). |
279 |
|
280 |
In essence, the process is similar to [1], but more work is done at |
281 |
compile time. |
282 |
|
283 |
A key idea to get optimal performances is that constant parameters can |
284 |
be passed to the simple operations. For that purpose, dummy ELF |
285 |
relocations are generated with gcc for each constant parameter. Then, |
286 |
the tool (@file{dyngen}) can locate the relocations and generate the |
287 |
appriopriate C code to resolve them when building the dynamic code. |
288 |
|
289 |
That way, QEMU is no more difficult to port than a dynamic linker. |
290 |
|
291 |
To go even faster, GCC static register variables are used to keep the |
292 |
state of the virtual CPU. |
293 |
|
294 |
@node Register allocation |
295 |
@section Register allocation |
296 |
|
297 |
Since QEMU uses fixed simple instructions, no efficient register |
298 |
allocation can be done. However, because RISC CPUs have a lot of |
299 |
register, most of the virtual CPU state can be put in registers without |
300 |
doing complicated register allocation. |
301 |
|
302 |
@node Condition code optimisations |
303 |
@section Condition code optimisations |
304 |
|
305 |
Good CPU condition codes emulation (@code{EFLAGS} register on x86) is a |
306 |
critical point to get good performances. QEMU uses lazy condition code |
307 |
evaluation: instead of computing the condition codes after each x86 |
308 |
instruction, it just stores one operand (called @code{CC_SRC}), the |
309 |
result (called @code{CC_DST}) and the type of operation (called |
310 |
@code{CC_OP}). |
311 |
|
312 |
@code{CC_OP} is almost never explicitely set in the generated code |
313 |
because it is known at translation time. |
314 |
|
315 |
In order to increase performances, a backward pass is performed on the |
316 |
generated simple instructions (see |
317 |
@code{target-i386/translate.c:optimize_flags()}). When it can be proved that |
318 |
the condition codes are not needed by the next instructions, no |
319 |
condition codes are computed at all. |
320 |
|
321 |
@node CPU state optimisations |
322 |
@section CPU state optimisations |
323 |
|
324 |
The x86 CPU has many internal states which change the way it evaluates |
325 |
instructions. In order to achieve a good speed, the translation phase |
326 |
considers that some state information of the virtual x86 CPU cannot |
327 |
change in it. For example, if the SS, DS and ES segments have a zero |
328 |
base, then the translator does not even generate an addition for the |
329 |
segment base. |
330 |
|
331 |
[The FPU stack pointer register is not handled that way yet]. |
332 |
|
333 |
@node Translation cache |
334 |
@section Translation cache |
335 |
|
336 |
A 16 MByte cache holds the most recently used translations. For |
337 |
simplicity, it is completely flushed when it is full. A translation unit |
338 |
contains just a single basic block (a block of x86 instructions |
339 |
terminated by a jump or by a virtual CPU state change which the |
340 |
translator cannot deduce statically). |
341 |
|
342 |
@node Direct block chaining |
343 |
@section Direct block chaining |
344 |
|
345 |
After each translated basic block is executed, QEMU uses the simulated |
346 |
Program Counter (PC) and other cpu state informations (such as the CS |
347 |
segment base value) to find the next basic block. |
348 |
|
349 |
In order to accelerate the most common cases where the new simulated PC |
350 |
is known, QEMU can patch a basic block so that it jumps directly to the |
351 |
next one. |
352 |
|
353 |
The most portable code uses an indirect jump. An indirect jump makes |
354 |
it easier to make the jump target modification atomic. On some host |
355 |
architectures (such as x86 or PowerPC), the @code{JUMP} opcode is |
356 |
directly patched so that the block chaining has no overhead. |
357 |
|
358 |
@node Self-modifying code and translated code invalidation |
359 |
@section Self-modifying code and translated code invalidation |
360 |
|
361 |
Self-modifying code is a special challenge in x86 emulation because no |
362 |
instruction cache invalidation is signaled by the application when code |
363 |
is modified. |
364 |
|
365 |
When translated code is generated for a basic block, the corresponding |
366 |
host page is write protected if it is not already read-only (with the |
367 |
system call @code{mprotect()}). Then, if a write access is done to the |
368 |
page, Linux raises a SEGV signal. QEMU then invalidates all the |
369 |
translated code in the page and enables write accesses to the page. |
370 |
|
371 |
Correct translated code invalidation is done efficiently by maintaining |
372 |
a linked list of every translated block contained in a given page. Other |
373 |
linked lists are also maintained to undo direct block chaining. |
374 |
|
375 |
Although the overhead of doing @code{mprotect()} calls is important, |
376 |
most MSDOS programs can be emulated at reasonnable speed with QEMU and |
377 |
DOSEMU. |
378 |
|
379 |
Note that QEMU also invalidates pages of translated code when it detects |
380 |
that memory mappings are modified with @code{mmap()} or @code{munmap()}. |
381 |
|
382 |
When using a software MMU, the code invalidation is more efficient: if |
383 |
a given code page is invalidated too often because of write accesses, |
384 |
then a bitmap representing all the code inside the page is |
385 |
built. Every store into that page checks the bitmap to see if the code |
386 |
really needs to be invalidated. It avoids invalidating the code when |
387 |
only data is modified in the page. |
388 |
|
389 |
@node Exception support |
390 |
@section Exception support |
391 |
|
392 |
longjmp() is used when an exception such as division by zero is |
393 |
encountered. |
394 |
|
395 |
The host SIGSEGV and SIGBUS signal handlers are used to get invalid |
396 |
memory accesses. The exact CPU state can be retrieved because all the |
397 |
x86 registers are stored in fixed host registers. The simulated program |
398 |
counter is found by retranslating the corresponding basic block and by |
399 |
looking where the host program counter was at the exception point. |
400 |
|
401 |
The virtual CPU cannot retrieve the exact @code{EFLAGS} register because |
402 |
in some cases it is not computed because of condition code |
403 |
optimisations. It is not a big concern because the emulated code can |
404 |
still be restarted in any cases. |
405 |
|
406 |
@node MMU emulation |
407 |
@section MMU emulation |
408 |
|
409 |
For system emulation, QEMU uses the mmap() system call to emulate the |
410 |
target CPU MMU. It works as long the emulated OS does not use an area |
411 |
reserved by the host OS (such as the area above 0xc0000000 on x86 |
412 |
Linux). |
413 |
|
414 |
In order to be able to launch any OS, QEMU also supports a soft |
415 |
MMU. In that mode, the MMU virtual to physical address translation is |
416 |
done at every memory access. QEMU uses an address translation cache to |
417 |
speed up the translation. |
418 |
|
419 |
In order to avoid flushing the translated code each time the MMU |
420 |
mappings change, QEMU uses a physically indexed translation cache. It |
421 |
means that each basic block is indexed with its physical address. |
422 |
|
423 |
When MMU mappings change, only the chaining of the basic blocks is |
424 |
reset (i.e. a basic block can no longer jump directly to another one). |
425 |
|
426 |
@node Hardware interrupts |
427 |
@section Hardware interrupts |
428 |
|
429 |
In order to be faster, QEMU does not check at every basic block if an |
430 |
hardware interrupt is pending. Instead, the user must asynchrously |
431 |
call a specific function to tell that an interrupt is pending. This |
432 |
function resets the chaining of the currently executing basic |
433 |
block. It ensures that the execution will return soon in the main loop |
434 |
of the CPU emulator. Then the main loop can test if the interrupt is |
435 |
pending and handle it. |
436 |
|
437 |
@node User emulation specific details |
438 |
@section User emulation specific details |
439 |
|
440 |
@subsection Linux system call translation |
441 |
|
442 |
QEMU includes a generic system call translator for Linux. It means that |
443 |
the parameters of the system calls can be converted to fix the |
444 |
endianness and 32/64 bit issues. The IOCTLs are converted with a generic |
445 |
type description system (see @file{ioctls.h} and @file{thunk.c}). |
446 |
|
447 |
QEMU supports host CPUs which have pages bigger than 4KB. It records all |
448 |
the mappings the process does and try to emulated the @code{mmap()} |
449 |
system calls in cases where the host @code{mmap()} call would fail |
450 |
because of bad page alignment. |
451 |
|
452 |
@subsection Linux signals |
453 |
|
454 |
Normal and real-time signals are queued along with their information |
455 |
(@code{siginfo_t}) as it is done in the Linux kernel. Then an interrupt |
456 |
request is done to the virtual CPU. When it is interrupted, one queued |
457 |
signal is handled by generating a stack frame in the virtual CPU as the |
458 |
Linux kernel does. The @code{sigreturn()} system call is emulated to return |
459 |
from the virtual signal handler. |
460 |
|
461 |
Some signals (such as SIGALRM) directly come from the host. Other |
462 |
signals are synthetized from the virtual CPU exceptions such as SIGFPE |
463 |
when a division by zero is done (see @code{main.c:cpu_loop()}). |
464 |
|
465 |
The blocked signal mask is still handled by the host Linux kernel so |
466 |
that most signal system calls can be redirected directly to the host |
467 |
Linux kernel. Only the @code{sigaction()} and @code{sigreturn()} system |
468 |
calls need to be fully emulated (see @file{signal.c}). |
469 |
|
470 |
@subsection clone() system call and threads |
471 |
|
472 |
The Linux clone() system call is usually used to create a thread. QEMU |
473 |
uses the host clone() system call so that real host threads are created |
474 |
for each emulated thread. One virtual CPU instance is created for each |
475 |
thread. |
476 |
|
477 |
The virtual x86 CPU atomic operations are emulated with a global lock so |
478 |
that their semantic is preserved. |
479 |
|
480 |
Note that currently there are still some locking issues in QEMU. In |
481 |
particular, the translated cache flush is not protected yet against |
482 |
reentrancy. |
483 |
|
484 |
@subsection Self-virtualization |
485 |
|
486 |
QEMU was conceived so that ultimately it can emulate itself. Although |
487 |
it is not very useful, it is an important test to show the power of the |
488 |
emulator. |
489 |
|
490 |
Achieving self-virtualization is not easy because there may be address |
491 |
space conflicts. QEMU solves this problem by being an executable ELF |
492 |
shared object as the ld-linux.so ELF interpreter. That way, it can be |
493 |
relocated at load time. |
494 |
|
495 |
@node Bibliography |
496 |
@section Bibliography |
497 |
|
498 |
@table @asis |
499 |
|
500 |
@item [1] |
501 |
@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing |
502 |
direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio |
503 |
Riccardi. |
504 |
|
505 |
@item [2] |
506 |
@url{http://developer.kde.org/~sewardj/}, Valgrind, an open-source |
507 |
memory debugger for x86-GNU/Linux, by Julian Seward. |
508 |
|
509 |
@item [3] |
510 |
@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project, |
511 |
by Kevin Lawton et al. |
512 |
|
513 |
@item [4] |
514 |
@url{http://www.cs.rose-hulman.edu/~donaldlf/em86/index.html}, the EM86 |
515 |
x86 emulator on Alpha-Linux. |
516 |
|
517 |
@item [5] |
518 |
@url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/@/full_papers/chernoff/chernoff.pdf}, |
519 |
DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton |
520 |
Chernoff and Ray Hookway. |
521 |
|
522 |
@item [6] |
523 |
@url{http://www.willows.com/}, Windows API library emulation from |
524 |
Willows Software. |
525 |
|
526 |
@item [7] |
527 |
@url{http://user-mode-linux.sourceforge.net/}, |
528 |
The User-mode Linux Kernel. |
529 |
|
530 |
@item [8] |
531 |
@url{http://www.plex86.org/}, |
532 |
The new Plex86 project. |
533 |
|
534 |
@item [9] |
535 |
@url{http://www.vmware.com/}, |
536 |
The VMWare PC virtualizer. |
537 |
|
538 |
@item [10] |
539 |
@url{http://www.microsoft.com/windowsxp/virtualpc/}, |
540 |
The VirtualPC PC virtualizer. |
541 |
|
542 |
@item [11] |
543 |
@url{http://www.twoostwo.org/}, |
544 |
The TwoOStwo PC virtualizer. |
545 |
|
546 |
@end table |
547 |
|
548 |
@node Regression Tests |
549 |
@chapter Regression Tests |
550 |
|
551 |
In the directory @file{tests/}, various interesting testing programs |
552 |
are available. There are used for regression testing. |
553 |
|
554 |
@menu |
555 |
* test-i386:: |
556 |
* linux-test:: |
557 |
* qruncom.c:: |
558 |
@end menu |
559 |
|
560 |
@node test-i386 |
561 |
@section @file{test-i386} |
562 |
|
563 |
This program executes most of the 16 bit and 32 bit x86 instructions and |
564 |
generates a text output. It can be compared with the output obtained with |
565 |
a real CPU or another emulator. The target @code{make test} runs this |
566 |
program and a @code{diff} on the generated output. |
567 |
|
568 |
The Linux system call @code{modify_ldt()} is used to create x86 selectors |
569 |
to test some 16 bit addressing and 32 bit with segmentation cases. |
570 |
|
571 |
The Linux system call @code{vm86()} is used to test vm86 emulation. |
572 |
|
573 |
Various exceptions are raised to test most of the x86 user space |
574 |
exception reporting. |
575 |
|
576 |
@node linux-test |
577 |
@section @file{linux-test} |
578 |
|
579 |
This program tests various Linux system calls. It is used to verify |
580 |
that the system call parameters are correctly converted between target |
581 |
and host CPUs. |
582 |
|
583 |
@node qruncom.c |
584 |
@section @file{qruncom.c} |
585 |
|
586 |
Example of usage of @code{libqemu} to emulate a user mode i386 CPU. |
587 |
|
588 |
@node Index |
589 |
@chapter Index |
590 |
@printindex cp |
591 |
|
592 |
@bye |