\input texinfo @c -*- texinfo -*-
-@settitle QEMU CPU Emulator Reference Documentation
+@iftex
+@settitle QEMU CPU Emulator User Documentation
@titlepage
@sp 7
-@center @titlefont{QEMU CPU Emulator Reference Documentation}
+@center @titlefont{QEMU CPU Emulator User Documentation}
@sp 3
@end titlepage
+@end iftex
@chapter Introduction
@section Features
-QEMU is a FAST! processor emulator. By using dynamic translation it
-achieves a reasonnable speed while being easy to port on new host
-CPUs.
+QEMU is a FAST! processor emulator using dynamic translation to
+achieve good emulation speed.
QEMU has two operating modes:
-@itemize
-@item User mode emulation. In this mode, QEMU can launch Linux processes
-compiled for one CPU on another CPU. Linux system calls are converted
-because of endianness and 32/64 bit mismatches. The Wine Windows API
-emulator (@url{http://www.winehq.org}) and the DOSEMU DOS emulator
-(@url{www.dosemu.org}) are the main targets for QEMU.
-
-@item Full system emulation. In this mode, QEMU emulates a full
-system, including a processor and various peripherials. Currently, it
-is only used to launch an x86 Linux kernel on an x86 Linux system. It
-enables easier testing and debugging of system code. It can also be
-used to provide virtual hosting of several virtual PCs on a single
-server.
+
+@itemize @minus
+
+@item
+Full system emulation. In this mode, QEMU emulates a full system (for
+example a PC), including a processor and various peripherials. It can
+be used to launch different Operating Systems without rebooting the
+PC or to debug system code.
+
+@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
+to ease cross-compilation and cross-debugging.
@end itemize
-As QEMU requires no host kernel patches to run, it is very safe and
+As QEMU requires no host kernel driver to run, it is very safe and
easy to use.
-QEMU generic features:
+For system emulation, the following hardware targets are supported:
+@itemize
+@item PC (x86 processor)
+@item PREP (PowerPC processor)
+@item PowerMac (PowerPC processor, in progress)
+@end itemize
-@itemize
+For user emulation, x86, PowerPC, ARM, and SPARC CPUs are supported.
-@item User space only or full system emulation.
+@chapter Installation
-@item Using dynamic translation to native code for reasonnable speed.
+If you want to compile QEMU yourself, see @ref{compilation}.
-@item Working on x86 and PowerPC hosts. Being tested on ARM, Sparc32, Alpha and S390.
+@section Linux
-@item Self-modifying code support.
+Download the binary distribution (@file{qemu-XXX-i386.tar.gz}) and
+untar it as root in @file{/}:
-@item Precise exceptions support.
+@example
+su
+cd /
+tar zxvf /tmp/qemu-XXX-i386.tar.gz
+@end example
-@item The virtual CPU is a library (@code{libqemu}) which can be used
-in other projects.
+@section Windows
-@end itemize
+Download the experimental binary installer at
+@url{http://www.freeoszoo.org/download.php}.
-QEMU user mode emulation features:
-@itemize
-@item Generic Linux system call converter, including most ioctls.
+@section Mac OS X
-@item clone() emulation using native CPU clone() to use Linux scheduler for threads.
+Download the experimental binary installer at
+@url{http://www.freeoszoo.org/download.php}.
-@item Accurate signal handling by remapping host signals to target signals.
-@end itemize
-@end itemize
+@chapter QEMU PC System emulator invocation
-QEMU full system emulation features:
-@itemize
-@item Using mmap() system calls to simulate the MMU
-@end itemize
+@section Introduction
-@section x86 emulation
+@c man begin DESCRIPTION
-QEMU x86 target features:
+The QEMU System emulator simulates a complete PC.
-@itemize
+In order to meet specific user needs, two versions of QEMU are
+available:
-@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.
+@enumerate
-@item Support of host page sizes bigger than 4KB in user mode emulation.
+@item
+@code{qemu-fast} uses the host Memory Management Unit (MMU) to
+simulate the x86 MMU. It is @emph{fast} but has limitations because
+the whole 4 GB address space cannot be used and some memory mapped
+peripherials cannot be emulated accurately yet. Therefore, a specific
+guest Linux kernel can be used (@xref{linux_compile}) as guest
+OS.
-@item QEMU can emulate itself on x86.
+Moreover there is no separation between the host and target address
+spaces, so it offers no security (the target OS can modify the
+@code{qemu-fast} code by writing at the right addresses).
-@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}.
-It can be used to test other x86 virtual CPUs.
+@item
+@code{qemu} uses a software MMU. It is about @emph{two times slower}
+but gives a more accurate emulation and a complete separation between
+the host and target address spaces.
+@end enumerate
+
+QEMU emulates the following PC peripherials:
+
+@itemize @minus
+@item
+i440FX host PCI bridge and PIIX3 PCI to ISA bridge
+@item
+Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
+extensions (hardware level, including all non standard modes).
+@item
+PS/2 mouse and keyboard
+@item
+2 PCI IDE interfaces with hard disk and CD-ROM support
+@item
+Floppy disk
+@item
+NE2000 PCI network adapters
+@item
+Serial ports
+@item
+Soundblaster 16 card
@end itemize
-Current QEMU limitations:
+QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
+VGA BIOS.
-@itemize
+@c man end
-@item No SSE/MMX support (yet).
+@section Quick Start
-@item No x86-64 support.
+Download and uncompress the linux image (@file{linux.img}) and type:
-@item IPC syscalls are missing.
+@example
+qemu linux.img
+@end example
-@item The x86 segment limits and access rights are not tested at every
-memory access.
+Linux should boot and give you a prompt.
-@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.
+@section Invocation
-@item Full system emulation only works if no data are mapped above the virtual address
-0xc0000000 (yet).
+@example
+@c man begin SYNOPSIS
+usage: qemu [options] [disk_image]
+@c man end
+@end example
-@item Some priviledged instructions or behaviors are missing. Only the ones
-needed for proper Linux kernel operation are emulated.
+@c man begin OPTIONS
+@var{disk_image} is a raw hard disk image for IDE hard disk 0.
-@item No memory separation between the kernel and the user processes is done.
-It will be implemented very soon.
+General options:
+@table @option
+@item -fda file
+@item -fdb file
+Use @var{file} as floppy disk 0/1 image (@xref{disk_images}). You can
+use the host floppy by using @file{/dev/fd0} as filename.
-@end itemize
+@item -hda file
+@item -hdb file
+@item -hdc file
+@item -hdd file
+Use @var{file} as hard disk 0, 1, 2 or 3 image (@xref{disk_images}).
-@section ARM emulation
+@item -cdrom file
+Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
+@option{-cdrom} at the same time). You can use the host CD-ROM by
+using @file{/dev/cdrom} as filename.
-@itemize
+@item -boot [a|c|d]
+Boot on floppy (a), hard disk (c) or CD-ROM (d). Hard disk boot is
+the default.
-@item ARM emulation can currently launch small programs while using the
-generic dynamic code generation architecture of QEMU.
+@item -snapshot
+Write to temporary files instead of disk image files. In this case,
+the raw disk image you use is not written back. You can however force
+the write back by pressing @key{C-a s} (@xref{disk_images}).
-@item No FPU support (yet).
+@item -m megs
+Set virtual RAM size to @var{megs} megabytes. Default is 128 MB.
-@item No automatic regression testing (yet).
+@item -nographic
-@end itemize
+Normally, QEMU uses SDL to display the VGA output. With this option,
+you can totally disable graphical output so that QEMU is a simple
+command line application. The emulated serial port is redirected on
+the console. Therefore, you can still use QEMU to debug a Linux kernel
+with a serial console.
-@chapter QEMU User space emulator invocation
+@item -enable-audio
-@section Quick Start
+The SB16 emulation is disabled by default as it may give problems with
+Windows. You can enable it manually with this option.
-If you need to compile QEMU, please read the @file{README} which gives
-the related information.
+@item -localtime
+Set the real time clock to local time (the default is to UTC
+time). This option is needed to have correct date in MS-DOS or
+Windows.
-In order to launch a Linux process, QEMU needs the process executable
-itself and all the target (x86) dynamic libraries used by it.
+@end table
-@itemize
+Network options:
-@item On x86, you can just try to launch any process by using the native
-libraries:
+@table @option
-@example
-qemu -L / /bin/ls
+@item -n script
+Set TUN/TAP network init script [default=/etc/qemu-ifup]. This script
+is launched to configure the host network interface (usually tun0)
+corresponding to the virtual NE2000 card.
+
+@item -macaddr addr
+
+Set the mac address of the first interface (the format is
+aa:bb:cc:dd:ee:ff in hexa). The mac address is incremented for each
+new network interface.
+
+@item -tun-fd fd
+Assumes @var{fd} talks to a tap/tun host network interface and use
+it. Read @url{http://bellard.org/qemu/tetrinet.html} to have an
+example of its use.
+
+@item -user-net
+Use the user mode network stack. This is the default if no tun/tap
+network init script is found.
+
+@item -tftp prefix
+When using the user mode network stack, activate a built-in TFTP
+server. All filenames beginning with @var{prefix} can be downloaded
+from the host to the guest using a TFTP client. The TFTP client on the
+guest must be configured in binary mode (use the command @code{bin} of
+the Unix TFTP client). The host IP address on the guest is as usual
+10.0.2.2.
+
+@item -redir [tcp|udp]:host-port:[guest-host]:guest-port
+
+When using the user mode network stack, redirect incoming TCP or UDP
+connections to the host port @var{host-port} to the guest
+@var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
+is not specified, its value is 10.0.2.15 (default address given by the
+built-in DHCP server).
+
+For example, to redirect host X11 connection from screen 1 to guest
+screen 0, use the following:
+
+@example
+# on the host
+qemu -redir tcp:6001::6000 [...]
+# this host xterm should open in the guest X11 server
+xterm -display :1
@end example
-@code{-L /} tells that the x86 dynamic linker must be searched with a
-@file{/} prefix.
+To redirect telnet connections from host port 5555 to telnet port on
+the guest, use the following:
+
+@example
+# on the host
+qemu -redir tcp:5555::23 [...]
+telnet localhost 5555
+@end example
+
+Then when you use on the host @code{telnet localhost 5555}, you
+connect to the guest telnet server.
+
+@item -dummy-net
+Use the dummy network stack: no packet will be received by the network
+cards.
+
+@end table
+
+Linux boot specific. When using this options, you can use a given
+Linux kernel without installing it in the disk image. It can be useful
+for easier testing of various kernels.
+
+@table @option
+
+@item -kernel bzImage
+Use @var{bzImage} as kernel image.
+
+@item -append cmdline
+Use @var{cmdline} as kernel command line
+
+@item -initrd file
+Use @var{file} as initial ram disk.
+
+@end table
+
+Debug/Expert options:
+@table @option
+
+@item -serial dev
+Redirect the virtual serial port to host device @var{dev}. Available
+devices are:
+@table @code
+@item vc
+Virtual console
+@item pty
+[Linux only] Pseudo TTY (a new PTY is automatically allocated)
+@item null
+void device
+@item stdio
+[Unix only] standard input/output
+@end table
+The default device is @code{vc} in graphical mode and @code{stdio} in
+non graphical mode.
+
+This option can be used several times to simulate up to 4 serials
+ports.
+
+@item -monitor dev
+Redirect the monitor to host device @var{dev} (same devices as the
+serial port).
+The default device is @code{vc} in graphical mode and @code{stdio} in
+non graphical mode.
+
+@item -s
+Wait gdb connection to port 1234 (@xref{gdb_usage}).
+@item -p port
+Change gdb connection port.
+@item -S
+Do not start CPU at startup (you must type 'c' in the monitor).
+@item -d
+Output log in /tmp/qemu.log
+@item -isa
+Simulate an ISA-only system (default is PCI system).
+@item -std-vga
+Simulate a standard VGA card with Bochs VBE extensions (default is
+Cirrus Logic GD5446 PCI VGA)
+
+@end table
+
+@c man end
+
+@section Keys
-@item Since QEMU is also a linux process, you can launch qemu with qemu:
+@c man begin OPTIONS
+
+During the graphical emulation, you can use the following keys:
+@table @key
+@item Ctrl-Shift-f
+Toggle full screen
+
+@item Ctrl-Shift-Fn
+Switch to virtual console 'n'. Standard console mappings are:
+@table @emph
+@item 1
+Target system display
+@item 2
+Monitor
+@item 3
+Serial port
+@end table
+
+@item Ctrl-Shift
+Toggle mouse and keyboard grab.
+@end table
+
+In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
+@key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
+
+During emulation, if you are using the @option{-nographic} option, use
+@key{Ctrl-a h} to get terminal commands:
+
+@table @key
+@item Ctrl-a h
+Print this help
+@item Ctrl-a x
+Exit emulatior
+@item Ctrl-a s
+Save disk data back to file (if -snapshot)
+@item Ctrl-a b
+Send break (magic sysrq in Linux)
+@item Ctrl-a c
+Switch between console and monitor
+@item Ctrl-a Ctrl-a
+Send Ctrl-a
+@end table
+@c man end
+
+@ignore
+
+@setfilename qemu
+@settitle QEMU System Emulator
+
+@c man begin SEEALSO
+The HTML documentation of QEMU for more precise information and Linux
+user mode emulator invocation.
+@c man end
+
+@c man begin AUTHOR
+Fabrice Bellard
+@c man end
+
+@end ignore
+
+@end ignore
+
+
+@section QEMU Monitor
+
+The QEMU monitor is used to give complex commands to the QEMU
+emulator. You can use it to:
+
+@itemize @minus
+
+@item
+Remove or insert removable medias images
+(such as CD-ROM or floppies)
+
+@item
+Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
+from a disk file.
+
+@item Inspect the VM state without an external debugger.
+
+@end itemize
+
+@subsection Commands
+
+The following commands are available:
+
+@table @option
+@item help or ? [cmd]
+Show the help for all commands or just for command @var{cmd}.
+
+@item commit
+Commit changes to the disk images (if -snapshot is used)
+
+@item info subcommand
+show various information about the system state
+
+@table @option
+@item info network
+show the network state
+@item info block
+show the block devices
+@item info registers
+show the cpu registers
+@item info history
+show the command line history
+@end table
+
+@item q or quit
+Quit the emulator.
+
+@item eject [-f] device
+Eject a removable media (use -f to force it).
+
+@item change device filename
+Change a removable media.
+
+@item screendump filename
+Save screen into PPM image @var{filename}.
+
+@item log item1[,...]
+Activate logging of the specified items to @file{/tmp/qemu.log}.
+
+@item savevm filename
+Save the whole virtual machine state to @var{filename}.
+
+@item loadvm filename
+Restore the whole virtual machine state from @var{filename}.
+
+@item stop
+Stop emulation.
+
+@item c or cont
+Resume emulation.
+
+@item gdbserver [port]
+Start gdbserver session (default port=1234)
+
+@item x/fmt addr
+Virtual memory dump starting at @var{addr}.
+
+@item xp /fmt addr
+Physical memory dump starting at @var{addr}.
+
+@var{fmt} is a format which tells the command how to format the
+data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
+
+@table @var
+@item count
+is the number of items to be dumped.
+
+@item format
+can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
+c (char) or i (asm instruction).
+
+@item size
+can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
+@code{h} or @code{w} can be specified with the @code{i} format to
+respectively select 16 or 32 bit code instruction size.
+
+@end table
+
+Examples:
+@itemize
+@item
+Dump 10 instructions at the current instruction pointer:
@example
-qemu -L / qemu -L / /bin/ls
+(qemu) x/10i $eip
+0x90107063: ret
+0x90107064: sti
+0x90107065: lea 0x0(%esi,1),%esi
+0x90107069: lea 0x0(%edi,1),%edi
+0x90107070: ret
+0x90107071: jmp 0x90107080
+0x90107073: nop
+0x90107074: nop
+0x90107075: nop
+0x90107076: nop
@end example
-@item On non x86 CPUs, you need first to download at least an x86 glibc
-(@file{qemu-XXX-i386-glibc21.tar.gz} on the QEMU web page). Ensure that
-@code{LD_LIBRARY_PATH} is not set:
+@item
+Dump 80 16 bit values at the start of the video memory.
+@example
+(qemu) xp/80hx 0xb8000
+0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
+0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
+0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
+0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
+0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
+0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
+0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
+0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
+0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
+0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
+@end example
+@end itemize
+
+@item p or print/fmt expr
+
+Print expression value. Only the @var{format} part of @var{fmt} is
+used.
+@item sendkey keys
+
+Send @var{keys} to the emulator. Use @code{-} to press several keys
+simultaneously. Example:
@example
-unset LD_LIBRARY_PATH
+sendkey ctrl-alt-f1
@end example
-Then you can launch the precompiled @file{ls} x86 executable:
+This command is useful to send keys that your graphical user interface
+intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
+
+@item system_reset
+
+Reset the system.
+
+@end table
+
+@subsection Integer expressions
+
+The monitor understands integers expressions for every integer
+argument. You can use register names to get the value of specifics
+CPU registers by prefixing them with @emph{$}.
+@node disk_images
+@section Disk Images
+
+@subsection Raw disk images
+
+The disk images can simply be raw images of the hard disk. You can
+create them with the command:
@example
-qemu /usr/local/qemu-i386/bin/ls-i386
+dd of=myimage bs=1024 seek=mysize count=0
@end example
-You can look at @file{/usr/local/qemu-i386/bin/qemu-conf.sh} so that
-QEMU is automatically launched by the Linux kernel when you try to
-launch x86 executables. It requires the @code{binfmt_misc} module in the
-Linux kernel.
+where @var{myimage} is the image filename and @var{mysize} is its size
+in kilobytes.
+
+@subsection Snapshot mode
+
+If you use the option @option{-snapshot}, all disk images are
+considered as read only. When sectors in written, they are written in
+a temporary file created in @file{/tmp}. You can however force the
+write back to the raw disk images by pressing @key{C-a s}.
+
+NOTE: The snapshot mode only works with raw disk images.
+
+@subsection Copy On Write disk images
+
+QEMU also supports user mode Linux
+(@url{http://user-mode-linux.sourceforge.net/}) Copy On Write (COW)
+disk images. The COW disk images are much smaller than normal images
+as they store only modified sectors. They also permit the use of the
+same disk image template for many users.
+
+To create a COW disk images, use the command:
-@item The x86 version of QEMU is also included. You can try weird things such as:
@example
-qemu /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386
+qemu-mkcow -f myrawimage.bin mycowimage.cow
@end example
-@end itemize
+@file{myrawimage.bin} is a raw image you want to use as original disk
+image. It will never be written to.
-@section Wine launch
+@file{mycowimage.cow} is the COW disk image which is created by
+@code{qemu-mkcow}. You can use it directly with the @option{-hdx}
+options. You must not modify the original raw disk image if you use
+COW images, as COW images only store the modified sectors from the raw
+disk image. QEMU stores the original raw disk image name and its
+modified time in the COW disk image so that chances of mistakes are
+reduced.
-@itemize
+If the raw disk image is not read-only, by pressing @key{C-a s} you
+can flush the COW disk image back into the raw disk image, as in
+snapshot mode.
-@item Ensure that you have a working QEMU with the x86 glibc
-distribution (see previous section). In order to verify it, you must be
-able to do:
+COW disk images can also be created without a corresponding raw disk
+image. It is useful to have a big initial virtual disk image without
+using much disk space. Use:
@example
-qemu /usr/local/qemu-i386/bin/ls-i386
+qemu-mkcow mycowimage.cow 1024
@end example
-@item Download the binary x86 Wine install
-(@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
+to create a 1 gigabyte empty COW disk image.
-@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}.
+NOTES:
+@enumerate
+@item
+COW disk images must be created on file systems supporting
+@emph{holes} such as ext2 or ext3.
+@item
+Since holes are used, the displayed size of the COW disk image is not
+the real one. To know it, use the @code{ls -ls} command.
+@end enumerate
-@item Then you can try the example @file{putty.exe}:
+@subsection Convert VMware disk images to raw disk images
+You can use the tool @file{vmdk2raw} to convert VMware disk images to
+raw disk images directly usable by QEMU. The syntax is:
@example
-qemu /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
+vmdk2raw vmware_image output_image
@end example
-@end itemize
+@section Network emulation
-@section Command line options
+QEMU simulates up to 6 networks cards (NE2000 boards). Each card can
+be connected to a specific host network interface.
+
+@subsection Using tun/tap network interface
+
+This is the standard way to emulate network. QEMU adds a virtual
+network device on your host (called @code{tun0}), and you can then
+configure it as if it was a real ethernet card.
+
+As an example, you can download the @file{linux-test-xxx.tar.gz}
+archive and copy the script @file{qemu-ifup} in @file{/etc} and
+configure properly @code{sudo} so that the command @code{ifconfig}
+contained in @file{qemu-ifup} can be executed as root. You must verify
+that your host kernel supports the TUN/TAP network interfaces: the
+device @file{/dev/net/tun} must be present.
+
+See @ref{direct_linux_boot} to have an example of network use with a
+Linux distribution.
+
+@subsection Using the user mode network stack
+
+By using the option @option{-user-net} or if you have no tun/tap init
+script, QEMU uses a completely user mode network stack (you don't need
+root priviledge to use the virtual network). The virtual network
+configuration is the following:
@example
-usage: qemu [-h] [-d] [-L path] [-s size] program [arguments...]
+
+QEMU Virtual Machine <------> Firewall/DHCP server <-----> Internet
+ (10.0.2.x) | (10.0.2.2)
+ |
+ ----> DNS
+ (10.0.2.3)
@end example
-@table @option
-@item -h
-Print the help
-@item -L path
-Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
-@item -s size
-Set the x86 stack size in bytes (default=524288)
-@end table
+The QEMU VM behaves as if it was behind a firewall which blocks all
+incoming connections. You can use a DHCP client to automatically
+configure the network in the QEMU VM.
-Debug options:
+In order to check that the user mode network is working, you can ping
+the address 10.0.2.2 and verify that you got an address in the range
+10.0.2.x from the QEMU virtual DHCP server.
-@table @option
-@item -d
-Activate log (logfile=/tmp/qemu.log)
-@item -p pagesize
-Act as if the host page size was 'pagesize' bytes
-@end table
+Note that @code{ping} is not supported reliably to the internet as it
+would require root priviledges. It means you can only ping the local
+router (10.0.2.2).
+
+When using the built-in TFTP server, the router is also the TFTP
+server.
-@chapter QEMU System emulator invocation
+When using the @option{-redir} option, TCP or UDP connections can be
+redirected from the host to the guest. It allows for example to
+redirect X11, telnet or SSH connections.
-@section Quick Start
+@node direct_linux_boot
+@section Direct Linux Boot
-This section explains how to launch a Linux kernel inside QEMU.
+This section explains how to launch a Linux kernel inside QEMU without
+having to make a full bootable image. It is very useful for fast Linux
+kernel testing. The QEMU network configuration is also explained.
@enumerate
@item
-Download the archive @file{vl-test-xxx.tar.gz} containing a Linux
-kernel and a disk image. The archive also contains a precompiled
-version of @file{vl}, the QEMU System emulator.
+Download the archive @file{linux-test-xxx.tar.gz} containing a Linux
+kernel and a disk image.
@item Optional: If you want network support (for example to launch X11 examples), you
-must copy the script @file{vl-ifup} in @file{/etc} and configure
+must copy the script @file{qemu-ifup} in @file{/etc} and configure
properly @code{sudo} so that the command @code{ifconfig} contained in
-@file{vl-ifup} can be executed as root. You must verify that your host
+@file{qemu-ifup} can be executed as root. You must verify that your host
kernel supports the TUN/TAP network interfaces: the device
@file{/dev/net/tun} must be present.
from the host kernel at IP address 172.20.0.2 and the host kernel is
seen from the emulated kernel at IP address 172.20.0.1.
-@item Launch @code{vl.sh}. You should have the following output:
+@item Launch @code{qemu.sh}. You should have the following output:
@example
-> ./vl.sh
-connected to host network interface: tun0
-Uncompressing Linux... Ok, booting the kernel.
-Linux version 2.4.20 (
[email protected]) (gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-110)) #22 lun jui 7 13:37:41 CEST 2003
+> ./qemu.sh
+Connected to host network interface: tun0
+Linux version 2.4.21 (
[email protected]) (gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #5 Tue Nov 11 18:18:53 CET 2003
BIOS-provided physical RAM map:
BIOS-e801: 0000000000000000 - 000000000009f000 (usable)
BIOS-e801: 0000000000100000 - 0000000002000000 (usable)
zone(0): 4096 pages.
zone(1): 4096 pages.
zone(2): 0 pages.
-Kernel command line: root=/dev/hda ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe
-ide_setup: ide1=noprobe
+Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe console=ttyS0
ide_setup: ide2=noprobe
ide_setup: ide3=noprobe
ide_setup: ide4=noprobe
ide_setup: ide5=noprobe
Initializing CPU#0
-Detected 501.285 MHz processor.
-Calibrating delay loop... 989.59 BogoMIPS
-Memory: 29268k/32768k available (907k kernel code, 3112k reserved, 212k data, 52k init, 0k highmem)
+Detected 2399.621 MHz processor.
+Console: colour EGA 80x25
+Calibrating delay loop... 4744.80 BogoMIPS
+Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, 0k highmem)
Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
-Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
+Mount cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
CPU: Intel Pentium Pro stepping 03
apm: BIOS not found.
Starting kswapd
Journalled Block Device driver loaded
+Detected PS/2 Mouse Port.
pty: 256 Unix98 ptys configured
Serial driver version 5.05c (2001-07-08) with no serial options enabled
ttyS00 at 0x03f8 (irq = 4) is a 16450
-Uniform Multi-Platform E-IDE driver Revision: 6.31
-ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
-hda: QEMU HARDDISK, ATA DISK drive
-ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
-hda: 12288 sectors (6 MB) w/256KiB Cache, CHS=12/16/63
-Partition check:
- hda: unknown partition table
Last modified Nov 1, 2000 by Paul Gortmaker
NE*000 ethercard probe at 0x300: 52 54 00 12 34 56
eth0: NE2000 found at 0x300, using IRQ 9.
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
+Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
+ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
+hda: QEMU HARDDISK, ATA DISK drive
+ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
+hda: attached ide-disk driver.
+hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63
+Partition check:
+ hda:
+Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 512 buckets, 4Kbytes
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
VFS: Mounted root (ext2 filesystem).
-Freeing unused kernel memory: 52k freed
-sh: can't access tty; job control turned off
-#
+Freeing unused kernel memory: 64k freed
+
+Linux version 2.4.21 (
[email protected]) (gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #5 Tue Nov 11 18:18:53 CET 2003
+
+QEMU Linux test distribution (based on Redhat 9)
+
+Type 'exit' to halt the system
+
+sh-2.05b#
@end example
@item
NOTES:
@enumerate
@item
-A 2.5.74 kernel is also included in the vl-test archive. Just
-replace the bzImage in vl.sh to try it.
+A 2.5.74 kernel is also included in the archive. Just
+replace the bzImage in qemu.sh to try it.
@item
-vl creates a temporary file in @var{$VLTMPDIR} (@file{/tmp} is the
+qemu-fast creates a temporary file in @var{$QEMU_TMPDIR} (@file{/tmp} is the
default) containing all the simulated PC memory. If possible, try to use
a temporary directory using the tmpfs filesystem to avoid too many
unnecessary disk accesses.
@item
-In order to exit cleanly for vl, you can do a @emph{shutdown} inside
-vl. vl will automatically exit when the Linux shutdown is done.
+In order to exit cleanly from qemu, you can do a @emph{shutdown} inside
+qemu. qemu will automatically exit when the Linux shutdown is done.
@item
You can boot slightly faster by disabling the probe of non present IDE
@end enumerate
-@section Invocation
-
-@example
-usage: vl [options] bzImage [kernel parameters...]
-@end example
-
-@file{bzImage} is a Linux kernel image.
-
-General options:
-@table @option
-@item -hda file
-@item -hdb file
-Use 'file' as hard disk 0 or 1 image (@xref{disk_images}).
-
-@item -snapshot
-
-Write to temporary files instead of disk image files. In this case,
-the raw disk image you use is not written back. You can however force
-the write back by pressing @key{C-a s} (@xref{disk_images}).
-
-@item -m megs
-Set virtual RAM size to @var{megs} megabytes.
-
-@item -n script
-Set network init script [default=/etc/vl-ifup]. This script is
-launched to configure the host network interface (usually tun0)
-corresponding to the virtual NE2000 card.
-
-@item -initrd file
-Use 'file' as initial ram disk.
-@end table
-
-Debug options:
-@table @option
-@item -s
-Wait gdb connection to port 1234.
-@item -p port
-Change gdb connection port.
-@item -d
-Output log in /tmp/vl.log
-@end table
-
-During emulation, use @key{C-a h} to get terminal commands:
-
-@table @key
-@item C-a h
-Print this help
-@item C-a x
-Exit emulatior
-@item C-a s
-Save disk data back to file (if -snapshot)
-@item C-a b
-Send break (magic sysrq)
-@item C-a C-a
-Send C-a
-@end table
-
-@node disk_images
-@section Disk Images
-
-@subsection Raw disk images
-
-The disk images can simply be raw images of the hard disk. You can
-create them with the command:
-@example
-dd if=/dev/zero of=myimage bs=1024 count=mysize
-@end example
-where @var{myimage} is the image filename and @var{mysize} is its size
-in kilobytes.
-
-@subsection Snapshot mode
-
-If you use the option @option{-snapshot}, all disk images are
-considered as read only. When sectors in written, they are written in
-a temporary file created in @file{/tmp}. You can however force the
-write back to the raw disk images by pressing @key{C-a s}.
-
-NOTE: The snapshot mode only works with raw disk images.
-
-@subsection Copy On Write disk images
-
-QEMU also supports user mode Linux
-(@url{http://user-mode-linux.sourceforge.net/}) Copy On Write (COW)
-disk images. The COW disk images are much smaller than normal images
-as they store only modified sectors. They also permit the use of the
-same disk image template for many users.
-
-To create a COW disk images, use the command:
-
-@example
-vlmkcow -f myrawimage.bin mycowimage.cow
-@end example
-
-@file{myrawimage.bin} is a raw image you want to use as original disk
-image. It will never be written to.
-
-@file{mycowimage.cow} is the COW disk image which is created by
-@code{vlmkcow}. You can use it directly with the @option{-hdx}
-options. You must not modify the original raw disk image if you use
-COW images, as COW images only store the modified sectors from the raw
-disk image. QEMU stores the original raw disk image name and its
-modified time in the COW disk image so that chances of mistakes are
-reduced.
-
-If the raw disk image is not read-only, by pressing @key{C-a s} you
-can flush the COW disk image back into the raw disk image, as in
-snapshot mode.
-
-COW disk images can also be created without a corresponding raw disk
-image. It is useful to have a big initial virtual disk image without
-using much disk space. Use:
-
-@example
-vlmkcow mycowimage.cow 1024
-@end example
-
-to create a 1 gigabyte empty COW disk image.
-
-NOTES:
-@enumerate
-@item
-COW disk images must be created on file systems supporting
-@emph{holes} such as ext2 or ext3.
-@item
-Since holes are used, the displayed size of the COW disk image is not
-the real one. To know it, use the @code{ls -ls} command.
-@end enumerate
-
+@node linux_compile
@section Linux Kernel Compilation
-You should be able to use any kernel with QEMU provided you make the
-following changes (only 2.4.x and 2.5.x were tested):
+You can use any linux kernel with QEMU. However, if you want to use
+@code{qemu-fast} to get maximum performances, you must use a modified
+guest kernel. If you are using a 2.6 guest kernel, you can use
+directly the patch @file{linux-2.6-qemu-fast.patch} made by Rusty
+Russel available in the QEMU source archive. Otherwise, you can make the
+following changes @emph{by hand} to the Linux kernel:
@enumerate
@item
use an SMP kernel with QEMU, it only supports one CPU.
@item
-If you are not using a 2.5 kernel as host kernel but if you use a target
-2.5 kernel, you must also ensure that the 'HZ' define is set to 100
+If you are not using a 2.6 kernel as host kernel but if you use a target
+2.6 kernel, you must also ensure that the 'HZ' define is set to 100
(1000 is the default) as QEMU cannot currently emulate timers at
-frequencies greater than 100 Hz on host Linux systems < 2.5. In
+frequencies greater than 100 Hz on host Linux systems < 2.6. In
@file{include/asm/param.h}, replace:
@example
exactly the same kernel as you would boot on your PC (in
@file{arch/i386/boot/bzImage}).
-@section PC Emulation
-
-QEMU emulates the following PC peripherials:
-
-@itemize
-@item
-PIC (interrupt controler)
-@item
-PIT (timers)
-@item
-CMOS memory
-@item
-Dumb VGA (to print the @code{Uncompressing Linux} message)
-@item
-Serial port (port=0x3f8, irq=4)
-@item
-NE2000 network adapter (port=0x300, irq=9)
-@item
-IDE disk interface (port=0x1f0, irq=14)
-@end itemize
-
+@node gdb_usage
@section GDB usage
QEMU has a primitive support to work with gdb, so that you can do
-'Ctrl-C' while the kernel is running and inspect its state.
+'Ctrl-C' while the virtual machine is running and inspect its state.
-In order to use gdb, launch vl with the '-s' option. It will wait for a
+In order to use gdb, launch qemu with the '-s' option. It will wait for a
gdb connection:
@example
-> vl -s arch/i386/boot/bzImage initrd-2.4.20.img root=/dev/ram0 ramdisk_size=6144
+> qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
Connected to host network interface: tun0
Waiting gdb connection on port 1234
@end example
In gdb, connect to QEMU:
@example
-(gdb) target remote locahost:1234
+(gdb) target remote localhost:1234
@end example
Then you can use gdb normally. For example, type 'c' to launch the kernel:
(gdb) c
@end example
-WARNING: breakpoints and single stepping are not yet supported.
-
-@chapter QEMU Internals
-
-@section QEMU compared to other emulators
-
-Like bochs [3], QEMU emulates an x86 CPU. But QEMU is much faster than
-bochs as it uses dynamic compilation and because it uses the host MMU to
-simulate the x86 MMU. The downside is that currently the emulation is
-not as accurate as bochs (for example, you cannot currently run Windows
-inside QEMU).
-
-Like Valgrind [2], QEMU does user space emulation and dynamic
-translation. Valgrind is mainly a memory debugger while QEMU has no
-support for it (QEMU could be used to detect out of bound memory
-accesses as Valgrind, but it has no support to track uninitialised data
-as Valgrind does). The Valgrind dynamic translator generates better code
-than QEMU (in particular it does register allocation) but it is closely
-tied to an x86 host and target and has no support for precise exceptions
-and system emulation.
-
-EM86 [4] is the closest project to user space QEMU (and QEMU still uses
-some of its 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.
-
-User mode Linux [7] was the only solution before QEMU to launch a Linux
-kernel as a process while not needing any host kernel patches. However,
-user mode Linux requires heavy kernel patches while QEMU accepts
-unpatched Linux kernels. It would be interesting to compare the
-performance of the two approaches.
-
-The new Plex86 [8] PC virtualizer is done in the same spirit as the QEMU
-system emulator. It requires a patched Linux kernel to work (you cannot
-launch the same kernel on your PC), but the patches are really small. As
-it is a PC virtualizer (no emulation is done except for some priveledged
-instructions), it has the potential of being faster than QEMU. The
-downside is that a complicated (and potentially unsafe) host kernel
-patch is needed.
-
-@section Portable dynamic translation
-
-QEMU is a dynamic translator. When it first encounters a piece of code,
-it converts it to the host instruction set. Usually dynamic translators
-are very complicated and highly CPU dependent. QEMU uses some tricks
-which make it relatively easily portable and simple while achieving good
-performances.
-
-The basic idea is to split every x86 instruction into fewer simpler
-instructions. Each simple instruction is implemented by a piece of C
-code (see @file{op-i386.c}). Then a compile time tool (@file{dyngen})
-takes the corresponding object file (@file{op-i386.o}) to generate a
-dynamic code generator which concatenates the simple instructions to
-build a function (see @file{op-i386.h:dyngen_code()}).
-
-In essence, the process is similar to [1], but more work is done at
-compile time.
+Here are some useful tips in order to use gdb on system code:
+
+@enumerate
+@item
+Use @code{info reg} to display all the CPU registers.
+@item
+Use @code{x/10i $eip} to display the code at the PC position.
+@item
+Use @code{set architecture i8086} to dump 16 bit code. Then use
+@code{x/10i $cs*16+*eip} to dump the code at the PC position.
+@end enumerate
+
+@section Target OS specific information
+
+@subsection Linux
+
+To have access to SVGA graphic modes under X11, use the @code{vesa} or
+the @code{cirrus} X11 driver. For optimal performances, use 16 bit
+color depth in the guest and the host OS.
+
+When using a 2.6 guest Linux kernel, you should add the option
+@code{clock=pit} on the kernel command line because the 2.6 Linux
+kernels make very strict real time clock checks by default that QEMU
+cannot simulate exactly.
+
+@subsection Windows
+
+If you have a slow host, using Windows 95 is better as it gives the
+best speed. Windows 2000 is also a good choice.
+
+@subsubsection SVGA graphic modes support
+
+QEMU emulates a Cirrus Logic GD5446 Video
+card. All Windows versions starting from Windows 95 should recognize
+and use this graphic card. For optimal performances, use 16 bit color
+depth in the guest and the host OS.
+
+@subsubsection CPU usage reduction
+
+Windows 9x does not correctly use the CPU HLT
+instruction. The result is that it takes host CPU cycles even when
+idle. You can install the utility from
+@url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
+problem. Note that no such tool is needed for NT, 2000 or XP.
+
+@subsubsection Windows 2000 disk full problems
+
+Currently (release 0.6.0) QEMU has a bug which gives a @code{disk
+full} error during installation of some releases of Windows 2000. The
+workaround is to stop QEMU as soon as you notice that your disk image
+size is growing too fast (monitor it with @code{ls -ls}). Then
+relaunch QEMU to continue the installation. If you still experience
+the problem, relaunch QEMU again.
+
+Future QEMU releases are likely to correct this bug.
+
+@subsubsection Windows XP security problems
+
+Some releases of Windows XP install correctly but give a security
+error when booting:
+@example
+A problem is preventing Windows from accurately checking the
+license for this computer. Error code: 0x800703e6.
+@end example
+The only known workaround is to boot in Safe mode
+without networking support.
+
+Future QEMU releases are likely to correct this bug.
+
+@subsection MS-DOS and FreeDOS
+
+@subsubsection CPU usage reduction
+
+DOS does not correctly use the CPU HLT instruction. The result is that
+it takes host CPU cycles even when idle. You can install the utility
+from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
+problem.
+
+@chapter QEMU PowerPC System emulator invocation
+
+Use the executable @file{qemu-system-ppc} to simulate a complete PREP
+or PowerMac PowerPC system.
-A key idea to get optimal performances is that constant parameters can
-be passed to the simple operations. For that purpose, dummy ELF
-relocations are generated with gcc for each constant parameter. Then,
-the tool (@file{dyngen}) can locate the relocations and generate the
-appriopriate C code to resolve them when building the dynamic code.
-
-That way, QEMU is no more difficult to port than a dynamic linker.
-
-To go even faster, GCC static register variables are used to keep the
-state of the virtual CPU.
+QEMU emulates the following PowerMac peripherials:
-@section Register allocation
-
-Since QEMU uses fixed simple instructions, no efficient register
-allocation can be done. However, because RISC CPUs have a lot of
-register, most of the virtual CPU state can be put in registers without
-doing complicated register allocation.
-
-@section Condition code optimisations
-
-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 just stores one operand (called @code{CC_SRC}), the
-result (called @code{CC_DST}) and the type of operation (called
-@code{CC_OP}).
-
-@code{CC_OP} is almost never explicitely set in the generated code
-because it is known at translation time.
-
-In order to increase performances, a backward pass is performed on the
-generated simple instructions (see
-@code{translate-i386.c:optimize_flags()}). When it can be proved that
-the condition codes are not needed by the next instructions, no
-condition codes are computed at all.
-
-@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
-considers that some state information of the virtual x86 CPU cannot
-change in it. For example, if the SS, DS and ES segments have a zero
-base, then the translator does not even generate an addition for the
-segment base.
-
-[The FPU stack pointer register is not handled that way yet].
-
-@section Translation cache
-
-A 2MByte cache holds the most recently used translations. For
-simplicity, it is completely flushed when it is full. A translation unit
-contains just a single basic block (a block of x86 instructions
-terminated by a jump or by a virtual CPU state change which the
-translator cannot deduce statically).
-
-@section Direct block chaining
-
-After each translated basic block is executed, QEMU uses the simulated
-Program Counter (PC) and other cpu state informations (such as the CS
-segment base value) to find the next basic block.
-
-In order to accelerate the most common cases where the new simulated PC
-is known, QEMU can patch a basic block so that it jumps directly to the
-next one.
-
-The most portable code uses an indirect jump. An indirect jump makes it
-easier to make the jump target modification atomic. On some
-architectures (such as PowerPC), the @code{JUMP} opcode is directly
-patched so that the block chaining has no overhead.
-
-@section Self-modifying code and translated code invalidation
+@itemize @minus
+@item
+UniNorth PCI Bridge
+@item
+PCI VGA compatible card with VESA Bochs Extensions
+@item
+2 PMAC IDE interfaces with hard disk and CD-ROM support
+@item
+NE2000 PCI adapters
+@item
+Non Volatile RAM
+@item
+VIA-CUDA with ADB keyboard and mouse.
+@end itemize
+
+QEMU emulates the following PREP peripherials:
+
+@itemize @minus
+@item
+PCI Bridge
+@item
+PCI VGA compatible card with VESA Bochs Extensions
+@item
+2 IDE interfaces with hard disk and CD-ROM support
+@item
+Floppy disk
+@item
+NE2000 network adapters
+@item
+Serial port
+@item
+PREP Non Volatile RAM
+@item
+PC compatible keyboard and mouse.
+@end itemize
+
+QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
+@url{http://site.voila.fr/jmayer/OpenHackWare/index.htm}.
+
+You can read the qemu PC system emulation chapter to have more
+informations about QEMU usage.
-Self-modifying code is a special challenge in x86 emulation because no
-instruction cache invalidation is signaled by the application when code
-is modified.
+@c man begin OPTIONS
-When translated code is generated for a basic block, the corresponding
-host page is write protected if it is not already read-only (with the
-system call @code{mprotect()}). Then, if a write access is done to the
-page, Linux raises a SEGV signal. QEMU then invalidates all the
-translated code in the page and enables write accesses to the page.
+The following options are specific to the PowerPC emulation:
-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.
+@table @option
+
+@item -prep
+Simulate a PREP system (default is PowerMAC)
-Although the overhead of doing @code{mprotect()} calls is important,
-most MSDOS programs can be emulated at reasonnable speed with QEMU and
-DOSEMU.
+@item -g WxH[xDEPTH]
-Note that QEMU also invalidates pages of translated code when it detects
-that memory mappings are modified with @code{mmap()} or @code{munmap()}.
+Set the initial VGA graphic mode. The default is 800x600x15.
+
+@end table
-@section Exception support
+@c man end
-longjmp() is used when an exception such as division by zero is
-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
-x86 registers are stored in fixed host registers. The simulated program
-counter is found by retranslating the corresponding basic block and by
-looking where the host program counter was at the exception point.
+More information is available at
+@url{http://jocelyn.mayer.free.fr/qemu-ppc/}.
-The virtual CPU cannot retrieve the exact @code{EFLAGS} register because
-in some cases it is not computed because of condition code
-optimisations. It is not a big concern because the emulated code can
-still be restarted in any cases.
+@chapter QEMU User space emulator invocation
-@section Linux system call translation
+@section Quick Start
-QEMU includes a generic system call translator for Linux. It means that
-the parameters of the system calls can be converted to fix the
-endianness and 32/64 bit issues. The IOCTLs are converted with a generic
-type description system (see @file{ioctls.h} and @file{thunk.c}).
+In order to launch a Linux process, QEMU needs the process executable
+itself and all the target (x86) dynamic libraries used by it.
-QEMU supports host CPUs which have pages bigger than 4KB. It records all
-the mappings the process does and try to emulated the @code{mmap()}
-system calls in cases where the host @code{mmap()} call would fail
-because of bad page alignment.
+@itemize
-@section Linux signals
+@item On x86, you can just try to launch any process by using the native
+libraries:
-Normal and real-time signals are queued along with their information
-(@code{siginfo_t}) as it is done in the Linux kernel. Then an interrupt
-request is done to the virtual CPU. When it is interrupted, one queued
-signal is handled by generating a stack frame in the virtual CPU as the
-Linux kernel does. The @code{sigreturn()} system call is emulated to return
-from the virtual signal handler.
+@example
+qemu-i386 -L / /bin/ls
+@end example
-Some signals (such as SIGALRM) directly come from the host. Other
-signals are synthetized from the virtual CPU exceptions such as SIGFPE
-when a division by zero is done (see @code{main.c:cpu_loop()}).
+@code{-L /} tells that the x86 dynamic linker must be searched with a
+@file{/} prefix.
-The blocked signal mask is still handled by the host Linux kernel so
-that most signal system calls can be redirected directly to the host
-Linux kernel. Only the @code{sigaction()} and @code{sigreturn()} system
-calls need to be fully emulated (see @file{signal.c}).
+@item Since QEMU is also a linux process, you can launch qemu with qemu (NOTE: you can only do that if you compiled QEMU from the sources):
-@section clone() system call and threads
+@example
+qemu-i386 -L / qemu-i386 -L / /bin/ls
+@end example
-The Linux clone() system call is usually used to create a thread. QEMU
-uses the host clone() system call so that real host threads are created
-for each emulated thread. One virtual CPU instance is created for each
-thread.
+@item On non x86 CPUs, you need first to download at least an x86 glibc
+(@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
+@code{LD_LIBRARY_PATH} is not set:
-The virtual x86 CPU atomic operations are emulated with a global lock so
-that their semantic is preserved.
+@example
+unset LD_LIBRARY_PATH
+@end example
-Note that currently there are still some locking issues in QEMU. In
-particular, the translated cache flush is not protected yet against
-reentrancy.
+Then you can launch the precompiled @file{ls} x86 executable:
-@section Self-virtualization
+@example
+qemu-i386 tests/i386/ls
+@end example
+You can look at @file{qemu-binfmt-conf.sh} so that
+QEMU is automatically launched by the Linux kernel when you try to
+launch x86 executables. It requires the @code{binfmt_misc} module in the
+Linux kernel.
-QEMU was conceived so that ultimately it can emulate itself. Although
-it is not very useful, it is an important test to show the power of the
-emulator.
+@item The x86 version of QEMU is also included. You can try weird things such as:
+@example
+qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386
+@end example
-Achieving self-virtualization is not easy because there may be address
-space conflicts. QEMU solves this problem by being an executable ELF
-shared object as the ld-linux.so ELF interpreter. That way, it can be
-relocated at load time.
+@end itemize
-@section MMU emulation
+@section Wine launch
-For system emulation, QEMU uses the mmap() system call to emulate the
-target CPU MMU. It works as long the emulated OS does not use an area
-reserved by the host OS (such as the area above 0xc0000000 on x86
-Linux).
+@itemize
-It is planned to add a slower but more precise MMU emulation
-with a software MMU.
+@item Ensure that you have a working QEMU with the x86 glibc
+distribution (see previous section). In order to verify it, you must be
+able to do:
-@section Bibliography
+@example
+qemu-i386 /usr/local/qemu-i386/bin/ls-i386
+@end example
-@table @asis
+@item Download the binary x86 Wine install
+(@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
-@item [1]
-@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing
-direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio
-Riccardi.
+@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}.
-@item [2]
-@url{http://developer.kde.org/~sewardj/}, Valgrind, an open-source
-memory debugger for x86-GNU/Linux, by Julian Seward.
+@item Then you can try the example @file{putty.exe}:
-@item [3]
-@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,
-by Kevin Lawton et al.
+@example
+qemu-i386 /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
+@end example
-@item [4]
-@url{http://www.cs.rose-hulman.edu/~donaldlf/em86/index.html}, the EM86
-x86 emulator on Alpha-Linux.
+@end itemize
-@item [5]
-@url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/full_papers/chernoff/chernoff.pdf},
-DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton
-Chernoff and Ray Hookway.
+@section Command line options
-@item [6]
-@url{http://www.willows.com/}, Windows API library emulation from
-Willows Software.
+@example
+usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
+@end example
-@item [7]
-@url{http://user-mode-linux.sourceforge.net/},
-The User-mode Linux Kernel.
+@table @option
+@item -h
+Print the help
+@item -L path
+Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
+@item -s size
+Set the x86 stack size in bytes (default=524288)
+@end table
-@item [8]
-@url{http://www.plex86.org/},
-The new Plex86 project.
+Debug options:
+@table @option
+@item -d
+Activate log (logfile=/tmp/qemu.log)
+@item -p pagesize
+Act as if the host page size was 'pagesize' bytes
@end table
-@chapter Regression Tests
+@node compilation
+@chapter Compilation from the sources
+
+@section Linux/BSD
-In the directory @file{tests/}, various interesting testing programs
-are available. There are used for regression testing.
+Read the @file{README} which gives the related information.
-@section @file{hello-i386}
+@section Windows
+
+@itemize
+@item Install the current versions of MSYS and MinGW from
+@url{http://www.mingw.org/}. You can find detailed installation
+instructions in the download section and the FAQ.
+
+@item Download
+the MinGW development library of SDL 1.2.x
+(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
+@url{http://www.libsdl.org}. Unpack it in a temporary place, and
+unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
+directory. Edit the @file{sdl-config} script so that it gives the
+correct SDL directory when invoked.
+
+@item Extract the current version of QEMU.
+
+@item Start the MSYS shell (file @file{msys.bat}).
+
+@item Change to the QEMU directory. Launch @file{./configure} and
+@file{make}. If you have problems using SDL, verify that
+@file{sdl-config} can be launched from the MSYS command line.
+
+@item You can install QEMU in @file{Program Files/Qemu} by typing
+@file{make install}. Don't forget to copy @file{SDL.dll} in
+@file{Program Files/Qemu}.
-Very simple statically linked x86 program, just to test QEMU during a
-port to a new host CPU.
+@end itemize
-@section @file{hello-arm}
+@section Cross compilation for Windows with Linux
-Very simple statically linked ARM program, just to test QEMU during a
-port to a new host CPU.
+@itemize
+@item
+Install the MinGW cross compilation tools available at
+@url{http://www.mingw.org/}.
-@section @file{test-i386}
+@item
+Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
+unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
+variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
+the QEMU configuration script.
-This program executes most of the 16 bit and 32 bit x86 instructions and
-generates a text output. It can be compared with the output obtained with
-a real CPU or another emulator. The target @code{make test} runs this
-program and a @code{diff} on the generated output.
+@item
+Configure QEMU for Windows cross compilation:
+@example
+./configure --enable-mingw32
+@end example
+If necessary, you can change the cross-prefix according to the prefix
+choosen for the MinGW tools with --cross-prefix. You can also use
+--prefix to set the Win32 install path.
-The Linux system call @code{modify_ldt()} is used to create x86 selectors
-to test some 16 bit addressing and 32 bit with segmentation cases.
+@item You can install QEMU in the installation directory by typing
+@file{make install}. Don't forget to copy @file{SDL.dll} in the
+installation directory.
-The Linux system call @code{vm86()} is used to test vm86 emulation.
+@end itemize
-Various exceptions are raised to test most of the x86 user space
-exception reporting.
+Note: Currently, Wine does not seem able to launch
+QEMU for Win32.
-@section @file{sha1}
+@section Mac OS X
-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.
+The Mac OS X patches are not fully merged in QEMU, so you should look
+at the QEMU mailing list archive to have all the necessary
+information.
projects / qemu.git / blobdiff