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Diffstat (limited to 'qemu-doc.texi')
| -rw-r--r-- | qemu-doc.texi | 41 |
1 files changed, 28 insertions, 13 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi index 3bb043be4c..c29dc22ad3 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -12,8 +12,9 @@ QEMU is an x86 processor emulator. Its purpose is to run x86 Linux processes on non-x86 Linux architectures such as PowerPC or ARM. By using dynamic translation it achieves a reasonnable speed while being -easy to port on new host CPUs. An obviously interesting x86 only process -is 'wine' (Windows emulation). +easy to port on new host CPUs. Its main goal is to be able to launch the +@code{Wine} Windows API emulator (@url{http://www.winehq.org}) on +non-x86 CPUs. QEMU features: @@ -21,12 +22,13 @@ QEMU features: @item User space only x86 emulator. -@item Currently ported on i386 and PowerPC. +@item Currently ported on i386, PowerPC and S390. -@item Using dynamic translation for reasonnable speed. +@item Using dynamic translation to native code for reasonnable speed. @item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation. -User space LDT and GDT are emulated. +User space LDT and GDT are emulated. VM86 mode is also supported +(experimental). @item Generic Linux system call converter, including most ioctls. @@ -52,10 +54,6 @@ Current QEMU Limitations: @item No support for self modifying code (yet). [Very few programs need that, a notable exception is QEMU itself !]. -@item No VM86 mode (yet), althought the virtual -CPU has support for most of it. [VM86 support is useful to launch old 16 -bit DOS programs with dosemu or wine]. - @item No SSE/MMX support (yet). @item No x86-64 support. @@ -123,10 +121,10 @@ able to do: qemu /usr/local/qemu-i386/bin/ls-i386 @end example -@item Download the binary x86 wine install +@item Download the binary x86 Wine install (@file{qemu-i386-wine.tar.gz} on the QEMU web page). -@item Configure wine on your account. Look at the provided script +@item Configure Wine on your account. Look at the provided script @file{/usr/local/qemu-i386/bin/wine-conf.sh}. Your previous @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}. @@ -177,6 +175,13 @@ code, in particular the ELF file loader). EM86 was limited to an alpha host and used a proprietary and slow interpreter (the interpreter part of the FX!32 Digital Win32 code translator [5]). +TWIN [6] is a Windows API emulator like Wine. It is less accurate than +Wine but includes a protected mode x86 interpreter to launch x86 Windows +executables. Such an approach as greater potential because most of the +Windows API is executed natively but it is far more difficult to develop +because all the data structures and function parameters exchanged +between the API and the x86 code must be converted. + @section Portable dynamic translation QEMU is a dynamic translator. When it first encounters a piece of code, @@ -218,7 +223,7 @@ doing complicated register allocation. Good CPU condition codes emulation (@code{EFLAGS} register on x86) is a critical point to get good performances. QEMU uses lazy condition code evaluation: instead of computing the condition codes after each x86 -instruction, it store justs one operand (called @code{CC_CRC}), the +instruction, it just stores one operand (called @code{CC_SRC}), the result (called @code{CC_DST}) and the type of operation (called @code{CC_OP}). @@ -231,7 +236,7 @@ generated simple instructions (see the condition codes are not needed by the next instructions, no condition codes are computed at all. -@section Translation CPU state optimisations +@section CPU state optimisations The x86 CPU has many internal states which change the way it evaluates instructions. In order to achieve a good speed, the translation phase @@ -323,6 +328,10 @@ x86 emulator on Alpha-Linux. DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton Chernoff and Ray Hookway. +@item [6] +@url{http://www.willows.com/}, Windows API library emulation from +Willows Software. + @end table @chapter Regression Tests @@ -365,3 +374,9 @@ It is a simple benchmark. Care must be taken to interpret the results because it mostly tests the ability of the virtual CPU to optimize the @code{rol} x86 instruction and the condition code computations. +@section @file{runcom} + +A very simple MSDOS emulator to test the Linux vm86() system call +emulation. The excellent 54 byte @file{pi_10.com} PI number calculator +can be launched with it. @file{pi_10.com} was written by Bertram +Felgenhauer (more information at @url{http://www.boo.net/~jasonp/pipage.html}). |