1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
4 @settitle QEMU CPU Emulator User Documentation
12 @center @titlefont{QEMU CPU Emulator}
14 @center @titlefont{User Documentation}
26 * QEMU PC System emulator::
27 * QEMU System emulator for non PC targets::
28 * QEMU Linux User space emulator::
29 * compilation:: Compilation from the sources
40 * intro_features:: Features
46 QEMU is a FAST! processor emulator using dynamic translation to
47 achieve good emulation speed.
49 QEMU has two operating modes:
54 Full system emulation. In this mode, QEMU emulates a full system (for
55 example a PC), including one or several processors and various
56 peripherals. It can be used to launch different Operating Systems
57 without rebooting the PC or to debug system code.
60 User mode emulation (Linux host only). In this mode, QEMU can launch
61 Linux processes compiled for one CPU on another CPU. It can be used to
62 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
63 to ease cross-compilation and cross-debugging.
67 QEMU can run without an host kernel driver and yet gives acceptable
70 For system emulation, the following hardware targets are supported:
72 @item PC (x86 or x86_64 processor)
73 @item ISA PC (old style PC without PCI bus)
74 @item PREP (PowerPC processor)
75 @item G3 BW PowerMac (PowerPC processor)
76 @item Mac99 PowerMac (PowerPC processor, in progress)
77 @item Sun4m (32-bit Sparc processor)
78 @item Sun4u (64-bit Sparc processor, in progress)
79 @item Malta board (32-bit MIPS processor)
80 @item ARM Integrator/CP (ARM926E or 1026E processor)
83 For user emulation, x86, PowerPC, ARM, MIPS, and Sparc32/64 CPUs are supported.
88 If you want to compile QEMU yourself, see @ref{compilation}.
91 * install_linux:: Linux
92 * install_windows:: Windows
93 * install_mac:: Macintosh
99 If a precompiled package is available for your distribution - you just
100 have to install it. Otherwise, see @ref{compilation}.
102 @node install_windows
105 Download the experimental binary installer at
106 @url{http://www.free.oszoo.org/@/download.html}.
111 Download the experimental binary installer at
112 @url{http://www.free.oszoo.org/@/download.html}.
114 @node QEMU PC System emulator
115 @chapter QEMU PC System emulator
118 * pcsys_introduction:: Introduction
119 * pcsys_quickstart:: Quick Start
120 * sec_invocation:: Invocation
122 * pcsys_monitor:: QEMU Monitor
123 * disk_images:: Disk Images
124 * pcsys_network:: Network emulation
125 * direct_linux_boot:: Direct Linux Boot
126 * pcsys_usb:: USB emulation
127 * gdb_usage:: GDB usage
128 * pcsys_os_specific:: Target OS specific information
131 @node pcsys_introduction
132 @section Introduction
134 @c man begin DESCRIPTION
136 The QEMU PC System emulator simulates the
137 following peripherals:
141 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
143 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
144 extensions (hardware level, including all non standard modes).
146 PS/2 mouse and keyboard
148 2 PCI IDE interfaces with hard disk and CD-ROM support
152 NE2000 PCI network adapters
156 Creative SoundBlaster 16 sound card
158 ENSONIQ AudioPCI ES1370 sound card
160 Adlib(OPL2) - Yamaha YM3812 compatible chip
162 PCI UHCI USB controller and a virtual USB hub.
165 SMP is supported with up to 255 CPUs.
167 Note that adlib is only available when QEMU was configured with
170 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
173 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
177 @node pcsys_quickstart
180 Download and uncompress the linux image (@file{linux.img}) and type:
186 Linux should boot and give you a prompt.
192 @c man begin SYNOPSIS
193 usage: qemu [options] [disk_image]
198 @var{disk_image} is a raw hard disk image for IDE hard disk 0.
203 Select the emulated machine (@code{-M ?} for list)
207 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). You can
208 use the host floppy by using @file{/dev/fd0} as filename.
214 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
217 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
218 @option{-cdrom} at the same time). You can use the host CD-ROM by
219 using @file{/dev/cdrom} as filename.
222 Boot on floppy (a), hard disk (c) or CD-ROM (d). Hard disk boot is
226 Write to temporary files instead of disk image files. In this case,
227 the raw disk image you use is not written back. You can however force
228 the write back by pressing @key{C-a s} (@pxref{disk_images}).
231 Set virtual RAM size to @var{megs} megabytes. Default is 128 MB.
234 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
239 Normally, QEMU uses SDL to display the VGA output. With this option,
240 you can totally disable graphical output so that QEMU is a simple
241 command line application. The emulated serial port is redirected on
242 the console. Therefore, you can still use QEMU to debug a Linux kernel
243 with a serial console.
247 Normally, QEMU uses SDL to display the VGA output. With this option,
248 you can have QEMU listen on VNC display d and redirect the VGA display
249 over the VNC session. It is very useful to enable the usb tablet device
250 when using this option (option @option{-usbdevice tablet}).
254 Use keyboard layout @var{language} (for example @code{fr} for
255 French). This option is only needed where it is not easy to get raw PC
256 keycodes (e.g. on Macs or with some X11 servers). You don't need to
257 use it on PC/Linux or PC/Windows hosts.
259 The available layouts are:
261 ar de-ch es fo fr-ca hu ja mk no pt-br sv
262 da en-gb et fr fr-ch is lt nl pl ru th
263 de en-us fi fr-be hr it lv nl-be pt sl tr
266 The default is @code{en-us}.
270 Will show the audio subsystem help: list of drivers, tunable
273 @item -soundhw card1,card2,... or -soundhw all
275 Enable audio and selected sound hardware. Use ? to print all
276 available sound hardware.
279 qemu -soundhw sb16,adlib hda
280 qemu -soundhw es1370 hda
281 qemu -soundhw all hda
286 Set the real time clock to local time (the default is to UTC
287 time). This option is needed to have correct date in MS-DOS or
291 Start in full screen.
294 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
298 Use it when installing Windows 2000 to avoid a disk full bug. After
299 Windows 2000 is installed, you no longer need this option (this option
300 slows down the IDE transfers).
308 Enable the USB driver (will be the default soon)
310 @item -usbdevice devname
311 Add the USB device @var{devname}. See the monitor command
312 @code{usb_add} to have more information.
319 @item -net nic[,vlan=n][,macaddr=addr][,model=type]
320 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
321 = 0 is the default). The NIC is currently an NE2000 on the PC
322 target. Optionally, the MAC address can be changed. If no
323 @option{-net} option is specified, a single NIC is created.
324 Qemu can emulate several different models of network card. Valid values for
325 @var{type} are @code{ne2k_pci}, @code{ne2k_isa}, @code{rtl8139},
326 @code{smc91c111} and @code{lance}. Not all devices are supported on all
329 @item -net user[,vlan=n][,hostname=name]
330 Use the user mode network stack which requires no administrator
331 priviledge to run. @option{hostname=name} can be used to specify the client
332 hostname reported by the builtin DHCP server.
334 @item -net tap[,vlan=n][,fd=h][,ifname=name][,script=file]
335 Connect the host TAP network interface @var{name} to VLAN @var{n} and
336 use the network script @var{file} to configure it. The default
337 network script is @file{/etc/qemu-ifup}. If @var{name} is not
338 provided, the OS automatically provides one. @option{fd=h} can be
339 used to specify the handle of an already opened host TAP interface. Example:
342 qemu linux.img -net nic -net tap
345 More complicated example (two NICs, each one connected to a TAP device)
347 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
348 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
352 @item -net socket[,vlan=n][,fd=h][,listen=[host]:port][,connect=host:port]
354 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
355 machine using a TCP socket connection. If @option{listen} is
356 specified, QEMU waits for incoming connections on @var{port}
357 (@var{host} is optional). @option{connect} is used to connect to
358 another QEMU instance using the @option{listen} option. @option{fd=h}
359 specifies an already opened TCP socket.
363 # launch a first QEMU instance
364 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
365 -net socket,listen=:1234
366 # connect the VLAN 0 of this instance to the VLAN 0
367 # of the first instance
368 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
369 -net socket,connect=127.0.0.1:1234
372 @item -net socket[,vlan=n][,fd=h][,mcast=maddr:port]
374 Create a VLAN @var{n} shared with another QEMU virtual
375 machines using a UDP multicast socket, effectively making a bus for
376 every QEMU with same multicast address @var{maddr} and @var{port}.
380 Several QEMU can be running on different hosts and share same bus (assuming
381 correct multicast setup for these hosts).
383 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
384 @url{http://user-mode-linux.sf.net}.
385 @item Use @option{fd=h} to specify an already opened UDP multicast socket.
390 # launch one QEMU instance
391 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
392 -net socket,mcast=230.0.0.1:1234
393 # launch another QEMU instance on same "bus"
394 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
395 -net socket,mcast=230.0.0.1:1234
396 # launch yet another QEMU instance on same "bus"
397 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
398 -net socket,mcast=230.0.0.1:1234
401 Example (User Mode Linux compat.):
403 # launch QEMU instance (note mcast address selected
405 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
406 -net socket,mcast=239.192.168.1:1102
408 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
412 Indicate that no network devices should be configured. It is used to
413 override the default configuration (@option{-net nic -net user}) which
414 is activated if no @option{-net} options are provided.
417 When using the user mode network stack, activate a built-in TFTP
418 server. All filenames beginning with @var{prefix} can be downloaded
419 from the host to the guest using a TFTP client. The TFTP client on the
420 guest must be configured in binary mode (use the command @code{bin} of
421 the Unix TFTP client). The host IP address on the guest is as usual
425 When using the user mode network stack, activate a built-in SMB
426 server so that Windows OSes can access to the host files in @file{dir}
429 In the guest Windows OS, the line:
433 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
434 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
436 Then @file{dir} can be accessed in @file{\\smbserver\qemu}.
438 Note that a SAMBA server must be installed on the host OS in
439 @file{/usr/sbin/smbd}. QEMU was tested succesfully with smbd version
440 2.2.7a from the Red Hat 9 and version 3.0.10-1.fc3 from Fedora Core 3.
442 @item -redir [tcp|udp]:host-port:[guest-host]:guest-port
444 When using the user mode network stack, redirect incoming TCP or UDP
445 connections to the host port @var{host-port} to the guest
446 @var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
447 is not specified, its value is 10.0.2.15 (default address given by the
448 built-in DHCP server).
450 For example, to redirect host X11 connection from screen 1 to guest
451 screen 0, use the following:
455 qemu -redir tcp:6001::6000 [...]
456 # this host xterm should open in the guest X11 server
460 To redirect telnet connections from host port 5555 to telnet port on
461 the guest, use the following:
465 qemu -redir tcp:5555::23 [...]
466 telnet localhost 5555
469 Then when you use on the host @code{telnet localhost 5555}, you
470 connect to the guest telnet server.
474 Linux boot specific: When using these options, you can use a given
475 Linux kernel without installing it in the disk image. It can be useful
476 for easier testing of various kernels.
480 @item -kernel bzImage
481 Use @var{bzImage} as kernel image.
483 @item -append cmdline
484 Use @var{cmdline} as kernel command line
487 Use @var{file} as initial ram disk.
491 Debug/Expert options:
495 Redirect the virtual serial port to host device @var{dev}. Available
501 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
505 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
506 parameters are set according to the emulated ones.
508 [Linux only, parallel port only] Use host parallel port
509 @var{N}. Currently only SPP parallel port features can be used.
511 Write output to filename. No character can be read.
513 [Unix only] standard input/output
515 [Unix only] name pipe @var{filename}
517 The default device is @code{vc} in graphical mode and @code{stdio} in
520 This option can be used several times to simulate up to 4 serials
524 Redirect the virtual parallel port to host device @var{dev} (same
525 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
526 be used to use hardware devices connected on the corresponding host
529 This option can be used several times to simulate up to 3 parallel
533 Redirect the monitor to host device @var{dev} (same devices as the
535 The default device is @code{vc} in graphical mode and @code{stdio} in
539 Wait gdb connection to port 1234 (@pxref{gdb_usage}).
541 Change gdb connection port.
543 Do not start CPU at startup (you must type 'c' in the monitor).
545 Output log in /tmp/qemu.log
546 @item -hdachs c,h,s,[,t]
547 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
548 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
549 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
550 all thoses parameters. This option is useful for old MS-DOS disk
554 Simulate a standard VGA card with Bochs VBE extensions (default is
555 Cirrus Logic GD5446 PCI VGA)
557 Start right away with a saved state (@code{loadvm} in monitor)
567 During the graphical emulation, you can use the following keys:
573 Switch to virtual console 'n'. Standard console mappings are:
576 Target system display
584 Toggle mouse and keyboard grab.
587 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
588 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
590 During emulation, if you are using the @option{-nographic} option, use
591 @key{Ctrl-a h} to get terminal commands:
599 Save disk data back to file (if -snapshot)
601 Send break (magic sysrq in Linux)
603 Switch between console and monitor
612 The HTML documentation of QEMU for more precise information and Linux
613 user mode emulator invocation.
623 @section QEMU Monitor
625 The QEMU monitor is used to give complex commands to the QEMU
626 emulator. You can use it to:
631 Remove or insert removable medias images
632 (such as CD-ROM or floppies)
635 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
638 @item Inspect the VM state without an external debugger.
644 The following commands are available:
648 @item help or ? [cmd]
649 Show the help for all commands or just for command @var{cmd}.
652 Commit changes to the disk images (if -snapshot is used)
654 @item info subcommand
655 show various information about the system state
659 show the various VLANs and the associated devices
661 show the block devices
663 show the cpu registers
665 show the command line history
667 show emulated PCI device
669 show USB devices plugged on the virtual USB hub
671 show all USB host devices
677 @item eject [-f] device
678 Eject a removable media (use -f to force it).
680 @item change device filename
681 Change a removable media.
683 @item screendump filename
684 Save screen into PPM image @var{filename}.
686 @item log item1[,...]
687 Activate logging of the specified items to @file{/tmp/qemu.log}.
689 @item savevm filename
690 Save the whole virtual machine state to @var{filename}.
692 @item loadvm filename
693 Restore the whole virtual machine state from @var{filename}.
701 @item gdbserver [port]
702 Start gdbserver session (default port=1234)
705 Virtual memory dump starting at @var{addr}.
708 Physical memory dump starting at @var{addr}.
710 @var{fmt} is a format which tells the command how to format the
711 data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
715 is the number of items to be dumped.
718 can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
719 c (char) or i (asm instruction).
722 can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
723 @code{h} or @code{w} can be specified with the @code{i} format to
724 respectively select 16 or 32 bit code instruction size.
731 Dump 10 instructions at the current instruction pointer:
736 0x90107065: lea 0x0(%esi,1),%esi
737 0x90107069: lea 0x0(%edi,1),%edi
739 0x90107071: jmp 0x90107080
747 Dump 80 16 bit values at the start of the video memory.
749 (qemu) xp/80hx 0xb8000
750 0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
751 0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
752 0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
753 0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
754 0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
755 0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
756 0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
757 0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
758 0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
759 0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
763 @item p or print/fmt expr
765 Print expression value. Only the @var{format} part of @var{fmt} is
770 Send @var{keys} to the emulator. Use @code{-} to press several keys
771 simultaneously. Example:
776 This command is useful to send keys that your graphical user interface
777 intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
783 @item usb_add devname
785 Plug the USB device devname to the QEMU virtual USB hub. @var{devname}
786 is either a virtual device name (for example @code{mouse}) or a host
787 USB device identifier. Host USB device identifiers have the following
788 syntax: @code{host:bus.addr} or @code{host:vendor_id:product_id}.
790 @item usb_del devname
792 Remove the USB device @var{devname} from the QEMU virtual USB
793 hub. @var{devname} has the syntax @code{bus.addr}. Use the monitor
794 command @code{info usb} to see the devices you can remove.
798 @subsection Integer expressions
800 The monitor understands integers expressions for every integer
801 argument. You can use register names to get the value of specifics
802 CPU registers by prefixing them with @emph{$}.
807 Since version 0.6.1, QEMU supports many disk image formats, including
808 growable disk images (their size increase as non empty sectors are
809 written), compressed and encrypted disk images.
812 * disk_images_quickstart:: Quick start for disk image creation
813 * disk_images_snapshot_mode:: Snapshot mode
814 * qemu_img_invocation:: qemu-img Invocation
815 * disk_images_fat_images:: Virtual FAT disk images
818 @node disk_images_quickstart
819 @subsection Quick start for disk image creation
821 You can create a disk image with the command:
823 qemu-img create myimage.img mysize
825 where @var{myimage.img} is the disk image filename and @var{mysize} is its
826 size in kilobytes. You can add an @code{M} suffix to give the size in
827 megabytes and a @code{G} suffix for gigabytes.
829 See @ref{qemu_img_invocation} for more information.
831 @node disk_images_snapshot_mode
832 @subsection Snapshot mode
834 If you use the option @option{-snapshot}, all disk images are
835 considered as read only. When sectors in written, they are written in
836 a temporary file created in @file{/tmp}. You can however force the
837 write back to the raw disk images by using the @code{commit} monitor
838 command (or @key{C-a s} in the serial console).
840 @node qemu_img_invocation
841 @subsection @code{qemu-img} Invocation
843 @include qemu-img.texi
845 @node disk_images_fat_images
846 @subsection Virtual FAT disk images
848 QEMU can automatically create a virtual FAT disk image from a
849 directory tree. In order to use it, just type:
852 qemu linux.img -hdb fat:/my_directory
855 Then you access access to all the files in the @file{/my_directory}
856 directory without having to copy them in a disk image or to export
857 them via SAMBA or NFS. The default access is @emph{read-only}.
859 Floppies can be emulated with the @code{:floppy:} option:
862 qemu linux.img -fda fat:floppy:/my_directory
865 A read/write support is available for testing (beta stage) with the
869 qemu linux.img -fda fat:floppy:rw:/my_directory
872 What you should @emph{never} do:
874 @item use non-ASCII filenames ;
875 @item use "-snapshot" together with ":rw:" ;
876 @item expect it to work when loadvm'ing ;
877 @item write to the FAT directory on the host system while accessing it with the guest system.
881 @section Network emulation
883 QEMU can simulate several networks cards (NE2000 boards on the PC
884 target) and can connect them to an arbitrary number of Virtual Local
885 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
886 VLAN. VLAN can be connected between separate instances of QEMU to
887 simulate large networks. For simpler usage, a non priviledged user mode
888 network stack can replace the TAP device to have a basic network
893 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
894 connection between several network devices. These devices can be for
895 example QEMU virtual Ethernet cards or virtual Host ethernet devices
898 @subsection Using TAP network interfaces
900 This is the standard way to connect QEMU to a real network. QEMU adds
901 a virtual network device on your host (called @code{tapN}), and you
902 can then configure it as if it was a real ethernet card.
904 As an example, you can download the @file{linux-test-xxx.tar.gz}
905 archive and copy the script @file{qemu-ifup} in @file{/etc} and
906 configure properly @code{sudo} so that the command @code{ifconfig}
907 contained in @file{qemu-ifup} can be executed as root. You must verify
908 that your host kernel supports the TAP network interfaces: the
909 device @file{/dev/net/tun} must be present.
911 See @ref{direct_linux_boot} to have an example of network use with a
912 Linux distribution and @ref{sec_invocation} to have examples of
913 command lines using the TAP network interfaces.
915 @subsection Using the user mode network stack
917 By using the option @option{-net user} (default configuration if no
918 @option{-net} option is specified), QEMU uses a completely user mode
919 network stack (you don't need root priviledge to use the virtual
920 network). The virtual network configuration is the following:
924 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
927 ----> DNS server (10.0.2.3)
929 ----> SMB server (10.0.2.4)
932 The QEMU VM behaves as if it was behind a firewall which blocks all
933 incoming connections. You can use a DHCP client to automatically
934 configure the network in the QEMU VM. The DHCP server assign addresses
935 to the hosts starting from 10.0.2.15.
937 In order to check that the user mode network is working, you can ping
938 the address 10.0.2.2 and verify that you got an address in the range
939 10.0.2.x from the QEMU virtual DHCP server.
941 Note that @code{ping} is not supported reliably to the internet as it
942 would require root priviledges. It means you can only ping the local
945 When using the built-in TFTP server, the router is also the TFTP
948 When using the @option{-redir} option, TCP or UDP connections can be
949 redirected from the host to the guest. It allows for example to
950 redirect X11, telnet or SSH connections.
952 @subsection Connecting VLANs between QEMU instances
954 Using the @option{-net socket} option, it is possible to make VLANs
955 that span several QEMU instances. See @ref{sec_invocation} to have a
958 @node direct_linux_boot
959 @section Direct Linux Boot
961 This section explains how to launch a Linux kernel inside QEMU without
962 having to make a full bootable image. It is very useful for fast Linux
963 kernel testing. The QEMU network configuration is also explained.
967 Download the archive @file{linux-test-xxx.tar.gz} containing a Linux
968 kernel and a disk image.
970 @item Optional: If you want network support (for example to launch X11 examples), you
971 must copy the script @file{qemu-ifup} in @file{/etc} and configure
972 properly @code{sudo} so that the command @code{ifconfig} contained in
973 @file{qemu-ifup} can be executed as root. You must verify that your host
974 kernel supports the TUN/TAP network interfaces: the device
975 @file{/dev/net/tun} must be present.
977 When network is enabled, there is a virtual network connection between
978 the host kernel and the emulated kernel. The emulated kernel is seen
979 from the host kernel at IP address 172.20.0.2 and the host kernel is
980 seen from the emulated kernel at IP address 172.20.0.1.
982 @item Launch @code{qemu.sh}. You should have the following output:
986 Connected to host network interface: tun0
987 Linux version 2.4.21 (bellard@@voyager.localdomain) (gcc version 3.2.2 20030222 @/(Red Hat @/Linux 3.2.2-5)) #5 Tue Nov 11 18:18:53 CET 2003
988 BIOS-provided physical RAM map:
989 BIOS-e801: 0000000000000000 - 000000000009f000 (usable)
990 BIOS-e801: 0000000000100000 - 0000000002000000 (usable)
991 32MB LOWMEM available.
992 On node 0 totalpages: 8192
996 Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe @/ide5=noprobe console=ttyS0
997 ide_setup: ide2=noprobe
998 ide_setup: ide3=noprobe
999 ide_setup: ide4=noprobe
1000 ide_setup: ide5=noprobe
1002 Detected 2399.621 MHz processor.
1003 Console: colour EGA 80x25
1004 Calibrating delay loop... 4744.80 BogoMIPS
1005 Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, @/0k highmem)
1006 Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
1007 Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
1008 Mount cache hash table entries: 512 (order: 0, 4096 bytes)
1009 Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
1010 Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
1011 CPU: Intel Pentium Pro stepping 03
1012 Checking 'hlt' instruction... OK.
1013 POSIX conformance testing by UNIFIX
1014 Linux NET4.0 for Linux 2.4
1015 Based upon Swansea University Computer Society NET3.039
1016 Initializing RT netlink socket
1017 apm: BIOS not found.
1019 Journalled Block Device driver loaded
1020 Detected PS/2 Mouse Port.
1021 pty: 256 Unix98 ptys configured
1022 Serial driver version 5.05c (2001-07-08) with no serial options enabled
1023 ttyS00 at 0x03f8 (irq = 4) is a 16450
1024 ne.c:v1.10 9/23/94 Donald Becker (becker@@scyld.com)
1025 Last modified Nov 1, 2000 by Paul Gortmaker
1026 NE*000 ethercard probe at 0x300: 52 54 00 12 34 56
1027 eth0: NE2000 found at 0x300, using IRQ 9.
1028 RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
1029 Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
1030 ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
1031 hda: QEMU HARDDISK, ATA DISK drive
1032 ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
1033 hda: attached ide-disk driver.
1034 hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63
1037 Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996
1038 NET4: Linux TCP/IP 1.0 for NET4.0
1039 IP Protocols: ICMP, UDP, TCP, IGMP
1040 IP: routing cache hash table of 512 buckets, 4Kbytes
1041 TCP: Hash tables configured (established 2048 bind 4096)
1042 NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
1043 EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
1044 VFS: Mounted root (ext2 filesystem).
1045 Freeing unused kernel memory: 64k freed
1047 Linux version 2.4.21 (bellard@@voyager.localdomain) (gcc version 3.2.2 20030222 @/(Red Hat @/Linux 3.2.2-5)) #5 Tue Nov 11 18:18:53 CET 2003
1049 QEMU Linux test distribution (based on Redhat 9)
1051 Type 'exit' to halt the system
1057 Then you can play with the kernel inside the virtual serial console. You
1058 can launch @code{ls} for example. Type @key{Ctrl-a h} to have an help
1059 about the keys you can type inside the virtual serial console. In
1060 particular, use @key{Ctrl-a x} to exit QEMU and use @key{Ctrl-a b} as
1061 the Magic SysRq key.
1064 If the network is enabled, launch the script @file{/etc/linuxrc} in the
1065 emulator (don't forget the leading dot):
1070 Then enable X11 connections on your PC from the emulated Linux:
1075 You can now launch @file{xterm} or @file{xlogo} and verify that you have
1076 a real Virtual Linux system !
1083 A 2.5.74 kernel is also included in the archive. Just
1084 replace the bzImage in qemu.sh to try it.
1087 In order to exit cleanly from qemu, you can do a @emph{shutdown} inside
1088 qemu. qemu will automatically exit when the Linux shutdown is done.
1091 You can boot slightly faster by disabling the probe of non present IDE
1092 interfaces. To do so, add the following options on the kernel command
1095 ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe
1099 The example disk image is a modified version of the one made by Kevin
1100 Lawton for the plex86 Project (@url{www.plex86.org}).
1105 @section USB emulation
1107 QEMU emulates a PCI UHCI USB controller and a 8 port USB hub connected
1108 to it. You can virtually plug to the hub virtual USB devices or real
1109 host USB devices (experimental, works only on Linux hosts).
1111 @subsection Using virtual USB devices
1113 A virtual USB mouse device is available for testing in QEMU.
1115 You can try it with the following monitor commands:
1118 # add the mouse device
1119 (qemu) usb_add mouse
1121 # show the virtual USB devices plugged on the QEMU Virtual USB hub
1123 Device 0.3, speed 12 Mb/s
1125 # after some time you can try to remove the mouse
1129 The option @option{-usbdevice} is similar to the monitor command
1132 @subsection Using host USB devices on a Linux host
1134 WARNING: this is an experimental feature. QEMU will slow down when
1135 using it. USB devices requiring real time streaming (i.e. USB Video
1136 Cameras) are not supported yet.
1139 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1140 is actually using the USB device. A simple way to do that is simply to
1141 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1142 to @file{mydriver.o.disabled}.
1144 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1150 @item Since only root can access to the USB devices directly, you can either launch QEMU as root or change the permissions of the USB devices you want to use. For testing, the following suffices:
1152 chown -R myuid /proc/bus/usb
1155 @item Launch QEMU and do in the monitor:
1158 Device 1.2, speed 480 Mb/s
1159 Class 00: USB device 1234:5678, USB DISK
1161 You should see the list of the devices you can use (Never try to use
1162 hubs, it won't work).
1164 @item Add the device in QEMU by using:
1166 usb_add host:1234:5678
1169 Normally the guest OS should report that a new USB device is
1170 plugged. You can use the option @option{-usbdevice} to do the same.
1172 @item Now you can try to use the host USB device in QEMU.
1176 When relaunching QEMU, you may have to unplug and plug again the USB
1177 device to make it work again (this is a bug).
1182 QEMU has a primitive support to work with gdb, so that you can do
1183 'Ctrl-C' while the virtual machine is running and inspect its state.
1185 In order to use gdb, launch qemu with the '-s' option. It will wait for a
1188 > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1189 -append "root=/dev/hda"
1190 Connected to host network interface: tun0
1191 Waiting gdb connection on port 1234
1194 Then launch gdb on the 'vmlinux' executable:
1199 In gdb, connect to QEMU:
1201 (gdb) target remote localhost:1234
1204 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1209 Here are some useful tips in order to use gdb on system code:
1213 Use @code{info reg} to display all the CPU registers.
1215 Use @code{x/10i $eip} to display the code at the PC position.
1217 Use @code{set architecture i8086} to dump 16 bit code. Then use
1218 @code{x/10i $cs*16+*eip} to dump the code at the PC position.
1221 @node pcsys_os_specific
1222 @section Target OS specific information
1226 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1227 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1228 color depth in the guest and the host OS.
1230 When using a 2.6 guest Linux kernel, you should add the option
1231 @code{clock=pit} on the kernel command line because the 2.6 Linux
1232 kernels make very strict real time clock checks by default that QEMU
1233 cannot simulate exactly.
1235 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1236 not activated because QEMU is slower with this patch. The QEMU
1237 Accelerator Module is also much slower in this case. Earlier Fedora
1238 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporte this
1239 patch by default. Newer kernels don't have it.
1243 If you have a slow host, using Windows 95 is better as it gives the
1244 best speed. Windows 2000 is also a good choice.
1246 @subsubsection SVGA graphic modes support
1248 QEMU emulates a Cirrus Logic GD5446 Video
1249 card. All Windows versions starting from Windows 95 should recognize
1250 and use this graphic card. For optimal performances, use 16 bit color
1251 depth in the guest and the host OS.
1253 @subsubsection CPU usage reduction
1255 Windows 9x does not correctly use the CPU HLT
1256 instruction. The result is that it takes host CPU cycles even when
1257 idle. You can install the utility from
1258 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1259 problem. Note that no such tool is needed for NT, 2000 or XP.
1261 @subsubsection Windows 2000 disk full problem
1263 Windows 2000 has a bug which gives a disk full problem during its
1264 installation. When installing it, use the @option{-win2k-hack} QEMU
1265 option to enable a specific workaround. After Windows 2000 is
1266 installed, you no longer need this option (this option slows down the
1269 @subsubsection Windows 2000 shutdown
1271 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1272 can. It comes from the fact that Windows 2000 does not automatically
1273 use the APM driver provided by the BIOS.
1275 In order to correct that, do the following (thanks to Struan
1276 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1277 Add/Troubleshoot a device => Add a new device & Next => No, select the
1278 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1279 (again) a few times. Now the driver is installed and Windows 2000 now
1280 correctly instructs QEMU to shutdown at the appropriate moment.
1282 @subsubsection Share a directory between Unix and Windows
1284 See @ref{sec_invocation} about the help of the option @option{-smb}.
1286 @subsubsection Windows XP security problems
1288 Some releases of Windows XP install correctly but give a security
1291 A problem is preventing Windows from accurately checking the
1292 license for this computer. Error code: 0x800703e6.
1294 The only known workaround is to boot in Safe mode
1295 without networking support.
1297 Future QEMU releases are likely to correct this bug.
1299 @subsection MS-DOS and FreeDOS
1301 @subsubsection CPU usage reduction
1303 DOS does not correctly use the CPU HLT instruction. The result is that
1304 it takes host CPU cycles even when idle. You can install the utility
1305 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1308 @node QEMU System emulator for non PC targets
1309 @chapter QEMU System emulator for non PC targets
1311 QEMU is a generic emulator and it emulates many non PC
1312 machines. Most of the options are similar to the PC emulator. The
1313 differences are mentionned in the following sections.
1316 * QEMU PowerPC System emulator::
1317 * Sparc32 System emulator invocation::
1318 * Sparc64 System emulator invocation::
1319 * MIPS System emulator invocation::
1320 * ARM System emulator invocation::
1323 @node QEMU PowerPC System emulator
1324 @section QEMU PowerPC System emulator
1326 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1327 or PowerMac PowerPC system.
1329 QEMU emulates the following PowerMac peripherals:
1335 PCI VGA compatible card with VESA Bochs Extensions
1337 2 PMAC IDE interfaces with hard disk and CD-ROM support
1343 VIA-CUDA with ADB keyboard and mouse.
1346 QEMU emulates the following PREP peripherals:
1352 PCI VGA compatible card with VESA Bochs Extensions
1354 2 IDE interfaces with hard disk and CD-ROM support
1358 NE2000 network adapters
1362 PREP Non Volatile RAM
1364 PC compatible keyboard and mouse.
1367 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1368 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1370 @c man begin OPTIONS
1372 The following options are specific to the PowerPC emulation:
1376 @item -g WxH[xDEPTH]
1378 Set the initial VGA graphic mode. The default is 800x600x15.
1385 More information is available at
1386 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
1388 @node Sparc32 System emulator invocation
1389 @section Sparc32 System emulator invocation
1391 Use the executable @file{qemu-system-sparc} to simulate a JavaStation
1392 (sun4m architecture). The emulation is somewhat complete.
1394 QEMU emulates the following sun4m peripherals:
1402 Lance (Am7990) Ethernet
1404 Non Volatile RAM M48T08
1406 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
1407 and power/reset logic
1409 ESP SCSI controller with hard disk and CD-ROM support
1414 The number of peripherals is fixed in the architecture.
1416 QEMU uses the Proll, a PROM replacement available at
1417 @url{http://people.redhat.com/@/zaitcev/linux/}. The required
1418 QEMU-specific patches are included with the sources.
1420 A sample Linux 2.6 series kernel and ram disk image are available on
1421 the QEMU web site. Please note that currently neither Linux 2.4
1422 series, NetBSD, nor OpenBSD kernels work.
1424 @c man begin OPTIONS
1426 The following options are specific to the Sparc emulation:
1432 Set the initial TCX graphic mode. The default is 1024x768.
1438 @node Sparc64 System emulator invocation
1439 @section Sparc64 System emulator invocation
1441 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u machine.
1442 The emulator is not usable for anything yet.
1444 QEMU emulates the following sun4u peripherals:
1448 UltraSparc IIi APB PCI Bridge
1450 PCI VGA compatible card with VESA Bochs Extensions
1452 Non Volatile RAM M48T59
1454 PC-compatible serial ports
1457 @node MIPS System emulator invocation
1458 @section MIPS System emulator invocation
1460 Use the executable @file{qemu-system-mips} to simulate a MIPS machine.
1461 The emulator is able to boot a Linux kernel and to run a Linux Debian
1462 installation from NFS. The following devices are emulated:
1468 PC style serial port
1473 More information is available in the QEMU mailing-list archive.
1475 @node ARM System emulator invocation
1476 @section ARM System emulator invocation
1478 Use the executable @file{qemu-system-arm} to simulate a ARM
1479 machine. The ARM Integrator/CP board is emulated with the following
1484 ARM926E or ARM1026E CPU
1488 SMC 91c111 Ethernet adapter
1491 A Linux 2.6 test image is available on the QEMU web site. More
1492 information is available in the QEMU mailing-list archive.
1494 @node QEMU Linux User space emulator
1495 @chapter QEMU Linux User space emulator
1500 * Command line options::
1504 @section Quick Start
1506 In order to launch a Linux process, QEMU needs the process executable
1507 itself and all the target (x86) dynamic libraries used by it.
1511 @item On x86, you can just try to launch any process by using the native
1515 qemu-i386 -L / /bin/ls
1518 @code{-L /} tells that the x86 dynamic linker must be searched with a
1521 @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):
1524 qemu-i386 -L / qemu-i386 -L / /bin/ls
1527 @item On non x86 CPUs, you need first to download at least an x86 glibc
1528 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
1529 @code{LD_LIBRARY_PATH} is not set:
1532 unset LD_LIBRARY_PATH
1535 Then you can launch the precompiled @file{ls} x86 executable:
1538 qemu-i386 tests/i386/ls
1540 You can look at @file{qemu-binfmt-conf.sh} so that
1541 QEMU is automatically launched by the Linux kernel when you try to
1542 launch x86 executables. It requires the @code{binfmt_misc} module in the
1545 @item The x86 version of QEMU is also included. You can try weird things such as:
1547 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
1548 /usr/local/qemu-i386/bin/ls-i386
1554 @section Wine launch
1558 @item Ensure that you have a working QEMU with the x86 glibc
1559 distribution (see previous section). In order to verify it, you must be
1563 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
1566 @item Download the binary x86 Wine install
1567 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
1569 @item Configure Wine on your account. Look at the provided script
1570 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
1571 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
1573 @item Then you can try the example @file{putty.exe}:
1576 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
1577 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
1582 @node Command line options
1583 @section Command line options
1586 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
1593 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
1595 Set the x86 stack size in bytes (default=524288)
1602 Activate log (logfile=/tmp/qemu.log)
1604 Act as if the host page size was 'pagesize' bytes
1608 @chapter Compilation from the sources
1613 * Cross compilation for Windows with Linux::
1620 @subsection Compilation
1622 First you must decompress the sources:
1625 tar zxvf qemu-x.y.z.tar.gz
1629 Then you configure QEMU and build it (usually no options are needed):
1635 Then type as root user:
1639 to install QEMU in @file{/usr/local}.
1641 @subsection Tested tool versions
1643 In order to compile QEMU succesfully, it is very important that you
1644 have the right tools. The most important one is gcc. I cannot guaranty
1645 that QEMU works if you do not use a tested gcc version. Look at
1646 'configure' and 'Makefile' if you want to make a different gcc
1650 host gcc binutils glibc linux distribution
1651 ----------------------------------------------------------------------
1652 x86 3.2 2.13.2 2.1.3 2.4.18
1653 2.96 2.11.93.0.2 2.2.5 2.4.18 Red Hat 7.3
1654 3.2.2 2.13.90.0.18 2.3.2 2.4.20 Red Hat 9
1656 PowerPC 3.3 [4] 2.13.90.0.18 2.3.1 2.4.20briq
1659 Alpha 3.3 [1] 2.14.90.0.4 2.2.5 2.2.20 [2] Debian 3.0
1661 Sparc32 2.95.4 2.12.90.0.1 2.2.5 2.4.18 Debian 3.0
1663 ARM 2.95.4 2.12.90.0.1 2.2.5 2.4.9 [3] Debian 3.0
1665 [1] On Alpha, QEMU needs the gcc 'visibility' attribute only available
1666 for gcc version >= 3.3.
1667 [2] Linux >= 2.4.20 is necessary for precise exception support
1669 [3] 2.4.9-ac10-rmk2-np1-cerf2
1671 [4] gcc 2.95.x generates invalid code when using too many register
1672 variables. You must use gcc 3.x on PowerPC.
1679 @item Install the current versions of MSYS and MinGW from
1680 @url{http://www.mingw.org/}. You can find detailed installation
1681 instructions in the download section and the FAQ.
1684 the MinGW development library of SDL 1.2.x
1685 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
1686 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
1687 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1688 directory. Edit the @file{sdl-config} script so that it gives the
1689 correct SDL directory when invoked.
1691 @item Extract the current version of QEMU.
1693 @item Start the MSYS shell (file @file{msys.bat}).
1695 @item Change to the QEMU directory. Launch @file{./configure} and
1696 @file{make}. If you have problems using SDL, verify that
1697 @file{sdl-config} can be launched from the MSYS command line.
1699 @item You can install QEMU in @file{Program Files/Qemu} by typing
1700 @file{make install}. Don't forget to copy @file{SDL.dll} in
1701 @file{Program Files/Qemu}.
1705 @node Cross compilation for Windows with Linux
1706 @section Cross compilation for Windows with Linux
1710 Install the MinGW cross compilation tools available at
1711 @url{http://www.mingw.org/}.
1714 Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
1715 unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
1716 variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
1717 the QEMU configuration script.
1720 Configure QEMU for Windows cross compilation:
1722 ./configure --enable-mingw32
1724 If necessary, you can change the cross-prefix according to the prefix
1725 choosen for the MinGW tools with --cross-prefix. You can also use
1726 --prefix to set the Win32 install path.
1728 @item You can install QEMU in the installation directory by typing
1729 @file{make install}. Don't forget to copy @file{SDL.dll} in the
1730 installation directory.
1734 Note: Currently, Wine does not seem able to launch
1740 The Mac OS X patches are not fully merged in QEMU, so you should look
1741 at the QEMU mailing list archive to have all the necessary