1 \input texinfo @c -*- texinfo -*-
4 @settitle QEMU CPU Emulator User Documentation
7 @center @titlefont{QEMU CPU Emulator User Documentation}
16 QEMU is a FAST! processor emulator using dynamic translation to
17 achieve good emulation speed.
19 QEMU has two operating modes:
24 Full system emulation. In this mode, QEMU emulates a full system (for
25 example a PC), including a processor and various peripherials. It can
26 be used to launch different Operating Systems without rebooting the
27 PC or to debug system code.
30 User mode emulation (Linux host only). In this mode, QEMU can launch
31 Linux processes compiled for one CPU on another CPU. It can be used to
32 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
33 to ease cross-compilation and cross-debugging.
37 As QEMU requires no host kernel driver to run, it is very safe and
40 For system emulation, the following hardware targets are supported:
42 @item PC (x86 processor)
43 @item PREP (PowerPC processor)
44 @item PowerMac (PowerPC processor, in progress)
47 For user emulation, x86, PowerPC, ARM, and SPARC CPUs are supported.
51 If you want to compile QEMU yourself, see @ref{compilation}.
55 Download the binary distribution (@file{qemu-XXX-i386.tar.gz}) and
56 untar it as root in @file{/}:
61 tar zxvf /tmp/qemu-XXX-i386.tar.gz
66 Download the experimental binary installer at
67 @url{http://www.freeoszoo.org/download.php}.
71 Download the experimental binary installer at
72 @url{http://www.freeoszoo.org/download.php}.
74 @chapter QEMU PC System emulator invocation
78 @c man begin DESCRIPTION
80 The QEMU System emulator simulates a complete PC.
82 In order to meet specific user needs, two versions of QEMU are
88 @code{qemu-fast} uses the host Memory Management Unit (MMU) to
89 simulate the x86 MMU. It is @emph{fast} but has limitations because
90 the whole 4 GB address space cannot be used and some memory mapped
91 peripherials cannot be emulated accurately yet. Therefore, a specific
92 guest Linux kernel can be used (@xref{linux_compile}) as guest
95 Moreover there is no separation between the host and target address
96 spaces, so it offers no security (the target OS can modify the
97 @code{qemu-fast} code by writing at the right addresses).
100 @code{qemu} uses a software MMU. It is about @emph{two times slower}
101 but gives a more accurate emulation and a complete separation between
102 the host and target address spaces.
106 QEMU emulates the following PC peripherials:
110 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
112 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
113 extensions (hardware level, including all non standard modes).
115 PS/2 mouse and keyboard
117 2 PCI IDE interfaces with hard disk and CD-ROM support
121 NE2000 PCI network adapters
128 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
135 Download and uncompress the linux image (@file{linux.img}) and type:
141 Linux should boot and give you a prompt.
146 @c man begin SYNOPSIS
147 usage: qemu [options] [disk_image]
152 @var{disk_image} is a raw hard disk image for IDE hard disk 0.
158 Use @var{file} as floppy disk 0/1 image (@xref{disk_images}). You can
159 use the host floppy by using @file{/dev/fd0} as filename.
165 Use @var{file} as hard disk 0, 1, 2 or 3 image (@xref{disk_images}).
168 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
169 @option{-cdrom} at the same time). You can use the host CD-ROM by
170 using @file{/dev/cdrom} as filename.
173 Boot on floppy (a), hard disk (c) or CD-ROM (d). Hard disk boot is
177 Write to temporary files instead of disk image files. In this case,
178 the raw disk image you use is not written back. You can however force
179 the write back by pressing @key{C-a s} (@xref{disk_images}).
182 Set virtual RAM size to @var{megs} megabytes. Default is 128 MB.
186 Normally, QEMU uses SDL to display the VGA output. With this option,
187 you can totally disable graphical output so that QEMU is a simple
188 command line application. The emulated serial port is redirected on
189 the console. Therefore, you can still use QEMU to debug a Linux kernel
190 with a serial console.
194 The SB16 emulation is disabled by default as it may give problems with
195 Windows. You can enable it manually with this option.
198 Set the real time clock to local time (the default is to UTC
199 time). This option is needed to have correct date in MS-DOS or
209 Set TUN/TAP network init script [default=/etc/qemu-ifup]. This script
210 is launched to configure the host network interface (usually tun0)
211 corresponding to the virtual NE2000 card.
215 Set the mac address of the first interface (the format is
216 aa:bb:cc:dd:ee:ff in hexa). The mac address is incremented for each
217 new network interface.
220 Assumes @var{fd} talks to a tap/tun host network interface and use
221 it. Read @url{http://bellard.org/qemu/tetrinet.html} to have an
225 Use the user mode network stack. This is the default if no tun/tap
226 network init script is found.
229 When using the user mode network stack, activate a built-in TFTP
230 server. All filenames beginning with @var{prefix} can be downloaded
231 from the host to the guest using a TFTP client. The TFTP client on the
232 guest must be configured in binary mode (use the command @code{bin} of
233 the Unix TFTP client). The host IP address on the guest is as usual
237 When using the user mode network stack, activate a built-in SMB
238 server so that Windows OSes can access to the host files in @file{dir}
241 In the guest Windows OS, the line:
245 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
246 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
248 Then @file{dir} can be accessed in @file{\\smbserver\qemu}.
250 Note that a SAMBA server must be installed on the host OS in
251 @file{/usr/sbin/smbd}. QEMU was tested succesfully with smbd version
252 2.2.7a from the Red Hat 9.
254 @item -redir [tcp|udp]:host-port:[guest-host]:guest-port
256 When using the user mode network stack, redirect incoming TCP or UDP
257 connections to the host port @var{host-port} to the guest
258 @var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
259 is not specified, its value is 10.0.2.15 (default address given by the
260 built-in DHCP server).
262 For example, to redirect host X11 connection from screen 1 to guest
263 screen 0, use the following:
267 qemu -redir tcp:6001::6000 [...]
268 # this host xterm should open in the guest X11 server
272 To redirect telnet connections from host port 5555 to telnet port on
273 the guest, use the following:
277 qemu -redir tcp:5555::23 [...]
278 telnet localhost 5555
281 Then when you use on the host @code{telnet localhost 5555}, you
282 connect to the guest telnet server.
285 Use the dummy network stack: no packet will be received by the network
290 Linux boot specific. When using this options, you can use a given
291 Linux kernel without installing it in the disk image. It can be useful
292 for easier testing of various kernels.
296 @item -kernel bzImage
297 Use @var{bzImage} as kernel image.
299 @item -append cmdline
300 Use @var{cmdline} as kernel command line
303 Use @var{file} as initial ram disk.
307 Debug/Expert options:
311 Redirect the virtual serial port to host device @var{dev}. Available
317 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
321 [Unix only] standard input/output
323 The default device is @code{vc} in graphical mode and @code{stdio} in
326 This option can be used several times to simulate up to 4 serials
330 Redirect the monitor to host device @var{dev} (same devices as the
332 The default device is @code{vc} in graphical mode and @code{stdio} in
336 Wait gdb connection to port 1234 (@xref{gdb_usage}).
338 Change gdb connection port.
340 Do not start CPU at startup (you must type 'c' in the monitor).
342 Output log in /tmp/qemu.log
344 Simulate an ISA-only system (default is PCI system).
346 Simulate a standard VGA card with Bochs VBE extensions (default is
347 Cirrus Logic GD5446 PCI VGA)
357 During the graphical emulation, you can use the following keys:
363 Switch to virtual console 'n'. Standard console mappings are:
366 Target system display
374 Toggle mouse and keyboard grab.
377 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
378 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
380 During emulation, if you are using the @option{-nographic} option, use
381 @key{Ctrl-a h} to get terminal commands:
389 Save disk data back to file (if -snapshot)
391 Send break (magic sysrq in Linux)
393 Switch between console and monitor
402 @settitle QEMU System Emulator
405 The HTML documentation of QEMU for more precise information and Linux
406 user mode emulator invocation.
418 @section QEMU Monitor
420 The QEMU monitor is used to give complex commands to the QEMU
421 emulator. You can use it to:
426 Remove or insert removable medias images
427 (such as CD-ROM or floppies)
430 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
433 @item Inspect the VM state without an external debugger.
439 The following commands are available:
443 @item help or ? [cmd]
444 Show the help for all commands or just for command @var{cmd}.
447 Commit changes to the disk images (if -snapshot is used)
449 @item info subcommand
450 show various information about the system state
454 show the network state
456 show the block devices
458 show the cpu registers
460 show the command line history
466 @item eject [-f] device
467 Eject a removable media (use -f to force it).
469 @item change device filename
470 Change a removable media.
472 @item screendump filename
473 Save screen into PPM image @var{filename}.
475 @item log item1[,...]
476 Activate logging of the specified items to @file{/tmp/qemu.log}.
478 @item savevm filename
479 Save the whole virtual machine state to @var{filename}.
481 @item loadvm filename
482 Restore the whole virtual machine state from @var{filename}.
490 @item gdbserver [port]
491 Start gdbserver session (default port=1234)
494 Virtual memory dump starting at @var{addr}.
497 Physical memory dump starting at @var{addr}.
499 @var{fmt} is a format which tells the command how to format the
500 data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
504 is the number of items to be dumped.
507 can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
508 c (char) or i (asm instruction).
511 can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
512 @code{h} or @code{w} can be specified with the @code{i} format to
513 respectively select 16 or 32 bit code instruction size.
520 Dump 10 instructions at the current instruction pointer:
525 0x90107065: lea 0x0(%esi,1),%esi
526 0x90107069: lea 0x0(%edi,1),%edi
528 0x90107071: jmp 0x90107080
536 Dump 80 16 bit values at the start of the video memory.
538 (qemu) xp/80hx 0xb8000
539 0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
540 0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
541 0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
542 0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
543 0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
544 0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
545 0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
546 0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
547 0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
548 0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
552 @item p or print/fmt expr
554 Print expression value. Only the @var{format} part of @var{fmt} is
559 Send @var{keys} to the emulator. Use @code{-} to press several keys
560 simultaneously. Example:
565 This command is useful to send keys that your graphical user interface
566 intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
574 @subsection Integer expressions
576 The monitor understands integers expressions for every integer
577 argument. You can use register names to get the value of specifics
578 CPU registers by prefixing them with @emph{$}.
583 @subsection Raw disk images
585 The disk images can simply be raw images of the hard disk. You can
586 create them with the command:
588 dd of=myimage bs=1024 seek=mysize count=0
590 where @var{myimage} is the image filename and @var{mysize} is its size
593 @subsection Snapshot mode
595 If you use the option @option{-snapshot}, all disk images are
596 considered as read only. When sectors in written, they are written in
597 a temporary file created in @file{/tmp}. You can however force the
598 write back to the raw disk images by pressing @key{C-a s}.
600 NOTE: The snapshot mode only works with raw disk images.
602 @subsection Copy On Write disk images
604 QEMU also supports user mode Linux
605 (@url{http://user-mode-linux.sourceforge.net/}) Copy On Write (COW)
606 disk images. The COW disk images are much smaller than normal images
607 as they store only modified sectors. They also permit the use of the
608 same disk image template for many users.
610 To create a COW disk images, use the command:
613 qemu-mkcow -f myrawimage.bin mycowimage.cow
616 @file{myrawimage.bin} is a raw image you want to use as original disk
617 image. It will never be written to.
619 @file{mycowimage.cow} is the COW disk image which is created by
620 @code{qemu-mkcow}. You can use it directly with the @option{-hdx}
621 options. You must not modify the original raw disk image if you use
622 COW images, as COW images only store the modified sectors from the raw
623 disk image. QEMU stores the original raw disk image name and its
624 modified time in the COW disk image so that chances of mistakes are
627 If the raw disk image is not read-only, by pressing @key{C-a s} you
628 can flush the COW disk image back into the raw disk image, as in
631 COW disk images can also be created without a corresponding raw disk
632 image. It is useful to have a big initial virtual disk image without
633 using much disk space. Use:
636 qemu-mkcow mycowimage.cow 1024
639 to create a 1 gigabyte empty COW disk image.
644 COW disk images must be created on file systems supporting
645 @emph{holes} such as ext2 or ext3.
647 Since holes are used, the displayed size of the COW disk image is not
648 the real one. To know it, use the @code{ls -ls} command.
651 @subsection Convert VMware disk images to raw disk images
653 You can use the tool @file{vmdk2raw} to convert VMware disk images to
654 raw disk images directly usable by QEMU. The syntax is:
656 vmdk2raw vmware_image output_image
659 @section Network emulation
661 QEMU simulates up to 6 networks cards (NE2000 boards). Each card can
662 be connected to a specific host network interface.
664 @subsection Using tun/tap network interface
666 This is the standard way to emulate network. QEMU adds a virtual
667 network device on your host (called @code{tun0}), and you can then
668 configure it as if it was a real ethernet card.
670 As an example, you can download the @file{linux-test-xxx.tar.gz}
671 archive and copy the script @file{qemu-ifup} in @file{/etc} and
672 configure properly @code{sudo} so that the command @code{ifconfig}
673 contained in @file{qemu-ifup} can be executed as root. You must verify
674 that your host kernel supports the TUN/TAP network interfaces: the
675 device @file{/dev/net/tun} must be present.
677 See @ref{direct_linux_boot} to have an example of network use with a
680 @subsection Using the user mode network stack
682 By using the option @option{-user-net} or if you have no tun/tap init
683 script, QEMU uses a completely user mode network stack (you don't need
684 root priviledge to use the virtual network). The virtual network
685 configuration is the following:
689 QEMU Virtual Machine <------> Firewall/DHCP server <-----> Internet
690 (10.0.2.x) | (10.0.2.2)
692 ----> DNS server (10.0.2.3)
694 ----> SMB server (10.0.2.4)
697 The QEMU VM behaves as if it was behind a firewall which blocks all
698 incoming connections. You can use a DHCP client to automatically
699 configure the network in the QEMU VM.
701 In order to check that the user mode network is working, you can ping
702 the address 10.0.2.2 and verify that you got an address in the range
703 10.0.2.x from the QEMU virtual DHCP server.
705 Note that @code{ping} is not supported reliably to the internet as it
706 would require root priviledges. It means you can only ping the local
709 When using the built-in TFTP server, the router is also the TFTP
712 When using the @option{-redir} option, TCP or UDP connections can be
713 redirected from the host to the guest. It allows for example to
714 redirect X11, telnet or SSH connections.
716 @node direct_linux_boot
717 @section Direct Linux Boot
719 This section explains how to launch a Linux kernel inside QEMU without
720 having to make a full bootable image. It is very useful for fast Linux
721 kernel testing. The QEMU network configuration is also explained.
725 Download the archive @file{linux-test-xxx.tar.gz} containing a Linux
726 kernel and a disk image.
728 @item Optional: If you want network support (for example to launch X11 examples), you
729 must copy the script @file{qemu-ifup} in @file{/etc} and configure
730 properly @code{sudo} so that the command @code{ifconfig} contained in
731 @file{qemu-ifup} can be executed as root. You must verify that your host
732 kernel supports the TUN/TAP network interfaces: the device
733 @file{/dev/net/tun} must be present.
735 When network is enabled, there is a virtual network connection between
736 the host kernel and the emulated kernel. The emulated kernel is seen
737 from the host kernel at IP address 172.20.0.2 and the host kernel is
738 seen from the emulated kernel at IP address 172.20.0.1.
740 @item Launch @code{qemu.sh}. You should have the following output:
744 Connected to host network interface: tun0
745 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
746 BIOS-provided physical RAM map:
747 BIOS-e801: 0000000000000000 - 000000000009f000 (usable)
748 BIOS-e801: 0000000000100000 - 0000000002000000 (usable)
749 32MB LOWMEM available.
750 On node 0 totalpages: 8192
754 Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe console=ttyS0
755 ide_setup: ide2=noprobe
756 ide_setup: ide3=noprobe
757 ide_setup: ide4=noprobe
758 ide_setup: ide5=noprobe
760 Detected 2399.621 MHz processor.
761 Console: colour EGA 80x25
762 Calibrating delay loop... 4744.80 BogoMIPS
763 Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, 0k highmem)
764 Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
765 Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
766 Mount cache hash table entries: 512 (order: 0, 4096 bytes)
767 Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
768 Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
769 CPU: Intel Pentium Pro stepping 03
770 Checking 'hlt' instruction... OK.
771 POSIX conformance testing by UNIFIX
772 Linux NET4.0 for Linux 2.4
773 Based upon Swansea University Computer Society NET3.039
774 Initializing RT netlink socket
777 Journalled Block Device driver loaded
778 Detected PS/2 Mouse Port.
779 pty: 256 Unix98 ptys configured
780 Serial driver version 5.05c (2001-07-08) with no serial options enabled
781 ttyS00 at 0x03f8 (irq = 4) is a 16450
782 ne.c:v1.10 9/23/94 Donald Becker (becker@scyld.com)
783 Last modified Nov 1, 2000 by Paul Gortmaker
784 NE*000 ethercard probe at 0x300: 52 54 00 12 34 56
785 eth0: NE2000 found at 0x300, using IRQ 9.
786 RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
787 Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
788 ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
789 hda: QEMU HARDDISK, ATA DISK drive
790 ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
791 hda: attached ide-disk driver.
792 hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63
795 Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996
796 NET4: Linux TCP/IP 1.0 for NET4.0
797 IP Protocols: ICMP, UDP, TCP, IGMP
798 IP: routing cache hash table of 512 buckets, 4Kbytes
799 TCP: Hash tables configured (established 2048 bind 4096)
800 NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
801 EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
802 VFS: Mounted root (ext2 filesystem).
803 Freeing unused kernel memory: 64k freed
805 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
807 QEMU Linux test distribution (based on Redhat 9)
809 Type 'exit' to halt the system
815 Then you can play with the kernel inside the virtual serial console. You
816 can launch @code{ls} for example. Type @key{Ctrl-a h} to have an help
817 about the keys you can type inside the virtual serial console. In
818 particular, use @key{Ctrl-a x} to exit QEMU and use @key{Ctrl-a b} as
822 If the network is enabled, launch the script @file{/etc/linuxrc} in the
823 emulator (don't forget the leading dot):
828 Then enable X11 connections on your PC from the emulated Linux:
833 You can now launch @file{xterm} or @file{xlogo} and verify that you have
834 a real Virtual Linux system !
841 A 2.5.74 kernel is also included in the archive. Just
842 replace the bzImage in qemu.sh to try it.
845 qemu-fast creates a temporary file in @var{$QEMU_TMPDIR} (@file{/tmp} is the
846 default) containing all the simulated PC memory. If possible, try to use
847 a temporary directory using the tmpfs filesystem to avoid too many
848 unnecessary disk accesses.
851 In order to exit cleanly from qemu, you can do a @emph{shutdown} inside
852 qemu. qemu will automatically exit when the Linux shutdown is done.
855 You can boot slightly faster by disabling the probe of non present IDE
856 interfaces. To do so, add the following options on the kernel command
859 ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe
863 The example disk image is a modified version of the one made by Kevin
864 Lawton for the plex86 Project (@url{www.plex86.org}).
869 @section Linux Kernel Compilation
871 You can use any linux kernel with QEMU. However, if you want to use
872 @code{qemu-fast} to get maximum performances, you must use a modified
873 guest kernel. If you are using a 2.6 guest kernel, you can use
874 directly the patch @file{linux-2.6-qemu-fast.patch} made by Rusty
875 Russel available in the QEMU source archive. Otherwise, you can make the
876 following changes @emph{by hand} to the Linux kernel:
880 The kernel must be mapped at 0x90000000 (the default is
881 0xc0000000). You must modify only two lines in the kernel source:
883 In @file{include/asm/page.h}, replace
885 #define __PAGE_OFFSET (0xc0000000)
889 #define __PAGE_OFFSET (0x90000000)
892 And in @file{arch/i386/vmlinux.lds}, replace
894 . = 0xc0000000 + 0x100000;
898 . = 0x90000000 + 0x100000;
902 If you want to enable SMP (Symmetric Multi-Processing) support, you
903 must make the following change in @file{include/asm/fixmap.h}. Replace
905 #define FIXADDR_TOP (0xffffX000UL)
909 #define FIXADDR_TOP (0xa7ffX000UL)
911 (X is 'e' or 'f' depending on the kernel version). Although you can
912 use an SMP kernel with QEMU, it only supports one CPU.
915 If you are not using a 2.6 kernel as host kernel but if you use a target
916 2.6 kernel, you must also ensure that the 'HZ' define is set to 100
917 (1000 is the default) as QEMU cannot currently emulate timers at
918 frequencies greater than 100 Hz on host Linux systems < 2.6. In
919 @file{include/asm/param.h}, replace:
922 # define HZ 1000 /* Internal kernel timer frequency */
926 # define HZ 100 /* Internal kernel timer frequency */
931 The file config-2.x.x gives the configuration of the example kernels.
938 As you would do to make a real kernel. Then you can use with QEMU
939 exactly the same kernel as you would boot on your PC (in
940 @file{arch/i386/boot/bzImage}).
945 QEMU has a primitive support to work with gdb, so that you can do
946 'Ctrl-C' while the virtual machine is running and inspect its state.
948 In order to use gdb, launch qemu with the '-s' option. It will wait for a
951 > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
952 Connected to host network interface: tun0
953 Waiting gdb connection on port 1234
956 Then launch gdb on the 'vmlinux' executable:
961 In gdb, connect to QEMU:
963 (gdb) target remote localhost:1234
966 Then you can use gdb normally. For example, type 'c' to launch the kernel:
971 Here are some useful tips in order to use gdb on system code:
975 Use @code{info reg} to display all the CPU registers.
977 Use @code{x/10i $eip} to display the code at the PC position.
979 Use @code{set architecture i8086} to dump 16 bit code. Then use
980 @code{x/10i $cs*16+*eip} to dump the code at the PC position.
983 @section Target OS specific information
987 To have access to SVGA graphic modes under X11, use the @code{vesa} or
988 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
989 color depth in the guest and the host OS.
991 When using a 2.6 guest Linux kernel, you should add the option
992 @code{clock=pit} on the kernel command line because the 2.6 Linux
993 kernels make very strict real time clock checks by default that QEMU
994 cannot simulate exactly.
998 If you have a slow host, using Windows 95 is better as it gives the
999 best speed. Windows 2000 is also a good choice.
1001 @subsubsection SVGA graphic modes support
1003 QEMU emulates a Cirrus Logic GD5446 Video
1004 card. All Windows versions starting from Windows 95 should recognize
1005 and use this graphic card. For optimal performances, use 16 bit color
1006 depth in the guest and the host OS.
1008 @subsubsection CPU usage reduction
1010 Windows 9x does not correctly use the CPU HLT
1011 instruction. The result is that it takes host CPU cycles even when
1012 idle. You can install the utility from
1013 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1014 problem. Note that no such tool is needed for NT, 2000 or XP.
1016 @subsubsection Windows 2000 disk full problems
1018 Currently (release 0.6.0) QEMU has a bug which gives a @code{disk
1019 full} error during installation of some releases of Windows 2000. The
1020 workaround is to stop QEMU as soon as you notice that your disk image
1021 size is growing too fast (monitor it with @code{ls -ls}). Then
1022 relaunch QEMU to continue the installation. If you still experience
1023 the problem, relaunch QEMU again.
1025 Future QEMU releases are likely to correct this bug.
1027 @subsubsection Windows XP security problems
1029 Some releases of Windows XP install correctly but give a security
1032 A problem is preventing Windows from accurately checking the
1033 license for this computer. Error code: 0x800703e6.
1035 The only known workaround is to boot in Safe mode
1036 without networking support.
1038 Future QEMU releases are likely to correct this bug.
1040 @subsection MS-DOS and FreeDOS
1042 @subsubsection CPU usage reduction
1044 DOS does not correctly use the CPU HLT instruction. The result is that
1045 it takes host CPU cycles even when idle. You can install the utility
1046 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1049 @chapter QEMU PowerPC System emulator invocation
1051 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1052 or PowerMac PowerPC system.
1054 QEMU emulates the following PowerMac peripherials:
1060 PCI VGA compatible card with VESA Bochs Extensions
1062 2 PMAC IDE interfaces with hard disk and CD-ROM support
1068 VIA-CUDA with ADB keyboard and mouse.
1071 QEMU emulates the following PREP peripherials:
1077 PCI VGA compatible card with VESA Bochs Extensions
1079 2 IDE interfaces with hard disk and CD-ROM support
1083 NE2000 network adapters
1087 PREP Non Volatile RAM
1089 PC compatible keyboard and mouse.
1092 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1093 @url{http://site.voila.fr/jmayer/OpenHackWare/index.htm}.
1095 You can read the qemu PC system emulation chapter to have more
1096 informations about QEMU usage.
1098 @c man begin OPTIONS
1100 The following options are specific to the PowerPC emulation:
1105 Simulate a PREP system (default is PowerMAC)
1107 @item -g WxH[xDEPTH]
1109 Set the initial VGA graphic mode. The default is 800x600x15.
1116 More information is available at
1117 @url{http://jocelyn.mayer.free.fr/qemu-ppc/}.
1119 @chapter QEMU User space emulator invocation
1121 @section Quick Start
1123 In order to launch a Linux process, QEMU needs the process executable
1124 itself and all the target (x86) dynamic libraries used by it.
1128 @item On x86, you can just try to launch any process by using the native
1132 qemu-i386 -L / /bin/ls
1135 @code{-L /} tells that the x86 dynamic linker must be searched with a
1138 @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):
1141 qemu-i386 -L / qemu-i386 -L / /bin/ls
1144 @item On non x86 CPUs, you need first to download at least an x86 glibc
1145 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
1146 @code{LD_LIBRARY_PATH} is not set:
1149 unset LD_LIBRARY_PATH
1152 Then you can launch the precompiled @file{ls} x86 executable:
1155 qemu-i386 tests/i386/ls
1157 You can look at @file{qemu-binfmt-conf.sh} so that
1158 QEMU is automatically launched by the Linux kernel when you try to
1159 launch x86 executables. It requires the @code{binfmt_misc} module in the
1162 @item The x86 version of QEMU is also included. You can try weird things such as:
1164 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386
1169 @section Wine launch
1173 @item Ensure that you have a working QEMU with the x86 glibc
1174 distribution (see previous section). In order to verify it, you must be
1178 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
1181 @item Download the binary x86 Wine install
1182 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
1184 @item Configure Wine on your account. Look at the provided script
1185 @file{/usr/local/qemu-i386/bin/wine-conf.sh}. Your previous
1186 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
1188 @item Then you can try the example @file{putty.exe}:
1191 qemu-i386 /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
1196 @section Command line options
1199 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
1206 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
1208 Set the x86 stack size in bytes (default=524288)
1215 Activate log (logfile=/tmp/qemu.log)
1217 Act as if the host page size was 'pagesize' bytes
1221 @chapter Compilation from the sources
1225 Read the @file{README} which gives the related information.
1230 @item Install the current versions of MSYS and MinGW from
1231 @url{http://www.mingw.org/}. You can find detailed installation
1232 instructions in the download section and the FAQ.
1235 the MinGW development library of SDL 1.2.x
1236 (@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1237 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
1238 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1239 directory. Edit the @file{sdl-config} script so that it gives the
1240 correct SDL directory when invoked.
1242 @item Extract the current version of QEMU.
1244 @item Start the MSYS shell (file @file{msys.bat}).
1246 @item Change to the QEMU directory. Launch @file{./configure} and
1247 @file{make}. If you have problems using SDL, verify that
1248 @file{sdl-config} can be launched from the MSYS command line.
1250 @item You can install QEMU in @file{Program Files/Qemu} by typing
1251 @file{make install}. Don't forget to copy @file{SDL.dll} in
1252 @file{Program Files/Qemu}.
1256 @section Cross compilation for Windows with Linux
1260 Install the MinGW cross compilation tools available at
1261 @url{http://www.mingw.org/}.
1264 Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
1265 unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
1266 variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
1267 the QEMU configuration script.
1270 Configure QEMU for Windows cross compilation:
1272 ./configure --enable-mingw32
1274 If necessary, you can change the cross-prefix according to the prefix
1275 choosen for the MinGW tools with --cross-prefix. You can also use
1276 --prefix to set the Win32 install path.
1278 @item You can install QEMU in the installation directory by typing
1279 @file{make install}. Don't forget to copy @file{SDL.dll} in the
1280 installation directory.
1284 Note: Currently, Wine does not seem able to launch
1289 The Mac OS X patches are not fully merged in QEMU, so you should look
1290 at the QEMU mailing list archive to have all the necessary