* intro_features:: Features
* intro_x86_emulation:: x86 emulation
* intro_arm_emulation:: ARM emulation
+* intro_mips_emulation:: MIPS emulation
* intro_ppc_emulation:: PowerPC emulation
* intro_sparc_emulation:: SPARC emulation
@end menu
@itemize @minus
-@item
+@item
Full system emulation. In this mode, QEMU emulates a full system
(usually a PC), including a processor and various peripherals. It can
be used to launch an different Operating System without rebooting the
PC or to debug system code.
-@item
+@item
User mode emulation (Linux host only). In this mode, QEMU can launch
Linux processes compiled for one CPU on another CPU. It can be used to
launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
QEMU generic features:
-@itemize
+@itemize
@item User space only or full system emulation.
@item Precise exceptions support.
-@item The virtual CPU is a library (@code{libqemu}) which can be used
+@item The virtual CPU is a library (@code{libqemu}) which can be used
in other projects (look at @file{qemu/tests/qruncom.c} to have an
example of user mode @code{libqemu} usage).
@end itemize
QEMU user mode emulation features:
-@itemize
+@itemize
@item Generic Linux system call converter, including most ioctls.
@item clone() emulation using native CPU clone() to use Linux scheduler for threads.
-@item Accurate signal handling by remapping host signals to target signals.
+@item Accurate signal handling by remapping host signals to target signals.
@end itemize
QEMU full system emulation features:
-@itemize
+@itemize
@item QEMU can either use a full software MMU for maximum portability or use the host system call mmap() to simulate the target MMU.
@end itemize
QEMU x86 target features:
-@itemize
+@itemize
-@item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation.
+@item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation.
LDT/GDT and IDT are emulated. VM86 mode is also supported to run DOSEMU.
@item Support of host page sizes bigger than 4KB in user mode emulation.
@item QEMU can emulate itself on x86.
-@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}.
+@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}.
It can be used to test other x86 virtual CPUs.
@end itemize
Current QEMU limitations:
-@itemize
+@itemize
@item No SSE/MMX support (yet).
@item IPC syscalls are missing.
-@item The x86 segment limits and access rights are not tested at every
+@item The x86 segment limits and access rights are not tested at every
memory access (yet). Hopefully, very few OSes seem to rely on that for
normal use.
-@item On non x86 host CPUs, @code{double}s are used instead of the non standard
+@item On non x86 host CPUs, @code{double}s are used instead of the non standard
10 byte @code{long double}s of x86 for floating point emulation to get
maximum performances.
@end itemize
+@node intro_mips_emulation
+@section MIPS emulation
+
+@itemize
+
+@item The system emulation allows full MIPS32/MIPS64 Release 2 emulation,
+including privileged instructions, FPU and MMU, in both little and big
+endian modes.
+
+@item The Linux userland emulation can run many 32 bit MIPS Linux binaries.
+
+@end itemize
+
+Current QEMU limitations:
+
+@itemize
+
+@item Self-modifying code is not always handled correctly.
+
+@item 64 bit userland emulation is not implemented.
+
+@item The system emulation is not complete enough to run real firmware.
+
+@item The watchpoint debug facility is not implemented.
+
+@end itemize
+
@node intro_ppc_emulation
@section PowerPC emulation
@itemize
-@item Full PowerPC 32 bit emulation, including privileged instructions,
+@item Full PowerPC 32 bit emulation, including privileged instructions,
FPU and MMU.
@item Can run most PowerPC Linux binaries.
@itemize
-@item Somewhat complete SPARC V8 emulation, including privileged
+@item Full SPARC V8 emulation, including privileged
instructions, FPU and MMU. SPARC V9 emulation includes most privileged
-instructions, FPU and I/D MMU, but misses VIS instructions.
+instructions, FPU and I/D MMU, but misses most VIS instructions.
-@item Can run some 32-bit SPARC Linux binaries.
+@item Can run most 32-bit SPARC Linux binaries and some handcrafted 64-bit SPARC Linux binaries.
@end itemize
Current QEMU limitations:
-@itemize
+@itemize
@item IPC syscalls are missing.
instructions to build a function (see @file{op.h:dyngen_code()}).
In essence, the process is similar to [1], but more work is done at
-compile time.
+compile time.
A key idea to get optimal performances is that constant parameters can
be passed to the simple operations. For that purpose, dummy ELF
Correct translated code invalidation is done efficiently by maintaining
a linked list of every translated block contained in a given page. Other
-linked lists are also maintained to undo direct block chaining.
+linked lists are also maintained to undo direct block chaining.
Although the overhead of doing @code{mprotect()} calls is important,
most MSDOS programs can be emulated at reasonnable speed with QEMU and
@section Exception support
longjmp() is used when an exception such as division by zero is
-encountered.
+encountered.
The host SIGSEGV and SIGBUS signal handlers are used to get invalid
memory accesses. The exact CPU state can be retrieved because all the
In order to avoid flushing the translated code each time the MMU
mappings change, QEMU uses a physically indexed translation cache. It
-means that each basic block is indexed with its physical address.
+means that each basic block is indexed with its physical address.
When MMU mappings change, only the chaining of the basic blocks is
reset (i.e. a basic block can no longer jump directly to another one).
@table @asis
-@item [1]
+@item [1]
@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing
direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio
Riccardi.
Willows Software.
@item [7]
-@url{http://user-mode-linux.sourceforge.net/},
+@url{http://user-mode-linux.sourceforge.net/},
The User-mode Linux Kernel.
@item [8]
-@url{http://www.plex86.org/},
+@url{http://www.plex86.org/},
The new Plex86 project.
@item [9]
-@url{http://www.vmware.com/},
+@url{http://www.vmware.com/},
The VMWare PC virtualizer.
@item [10]
-@url{http://www.microsoft.com/windowsxp/virtualpc/},
+@url{http://www.microsoft.com/windowsxp/virtualpc/},
The VirtualPC PC virtualizer.
@item [11]
-@url{http://www.twoostwo.org/},
+@url{http://www.twoostwo.org/},
The TwoOStwo PC virtualizer.
@end table
@chapter Regression Tests
In the directory @file{tests/}, various interesting testing programs
-are available. There are used for regression testing.
+are available. They are used for regression testing.
@menu
* test-i386::
projects / qemu.git / blobdiff