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}) in
56 @file{/tmp} and untar it as root from @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 Use keyboard layout @var{language} (for example @code{fr} for
195 French). This option is only needed where it is not easy to get raw PC
196 keycodes (e.g. on Macs or with some X11 servers). You don't need to
197 use it on PC/Linux or PC/Windows hosts.
199 The available layouts are:
201 ar de-ch es fo fr-ca hu ja mk no pt-br sv
202 da en-gb et fr fr-ch is lt nl pl ru th
203 de en-us fi fr-be hr it lv nl-be pt sl tr
206 The default is @code{en-us}.
210 The SB16 emulation is disabled by default as it may give problems with
211 Windows. You can enable it manually with this option.
214 Set the real time clock to local time (the default is to UTC
215 time). This option is needed to have correct date in MS-DOS or
219 Start in full screen.
222 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
232 Set TUN/TAP network init script [default=/etc/qemu-ifup]. This script
233 is launched to configure the host network interface (usually tun0)
234 corresponding to the virtual NE2000 card.
238 Set the mac address of the first interface (the format is
239 aa:bb:cc:dd:ee:ff in hexa). The mac address is incremented for each
240 new network interface.
243 Assumes @var{fd} talks to a tap/tun host network interface and use
244 it. Read @url{http://bellard.org/qemu/tetrinet.html} to have an
248 Use the user mode network stack. This is the default if no tun/tap
249 network init script is found.
252 When using the user mode network stack, activate a built-in TFTP
253 server. All filenames beginning with @var{prefix} can be downloaded
254 from the host to the guest using a TFTP client. The TFTP client on the
255 guest must be configured in binary mode (use the command @code{bin} of
256 the Unix TFTP client). The host IP address on the guest is as usual
260 When using the user mode network stack, activate a built-in SMB
261 server so that Windows OSes can access to the host files in @file{dir}
264 In the guest Windows OS, the line:
268 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
269 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
271 Then @file{dir} can be accessed in @file{\\smbserver\qemu}.
273 Note that a SAMBA server must be installed on the host OS in
274 @file{/usr/sbin/smbd}. QEMU was tested succesfully with smbd version
275 2.2.7a from the Red Hat 9.
277 @item -redir [tcp|udp]:host-port:[guest-host]:guest-port
279 When using the user mode network stack, redirect incoming TCP or UDP
280 connections to the host port @var{host-port} to the guest
281 @var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
282 is not specified, its value is 10.0.2.15 (default address given by the
283 built-in DHCP server).
285 For example, to redirect host X11 connection from screen 1 to guest
286 screen 0, use the following:
290 qemu -redir tcp:6001::6000 [...]
291 # this host xterm should open in the guest X11 server
295 To redirect telnet connections from host port 5555 to telnet port on
296 the guest, use the following:
300 qemu -redir tcp:5555::23 [...]
301 telnet localhost 5555
304 Then when you use on the host @code{telnet localhost 5555}, you
305 connect to the guest telnet server.
308 Use the dummy network stack: no packet will be received by the network
313 Linux boot specific. When using this options, you can use a given
314 Linux kernel without installing it in the disk image. It can be useful
315 for easier testing of various kernels.
319 @item -kernel bzImage
320 Use @var{bzImage} as kernel image.
322 @item -append cmdline
323 Use @var{cmdline} as kernel command line
326 Use @var{file} as initial ram disk.
330 Debug/Expert options:
334 Redirect the virtual serial port to host device @var{dev}. Available
340 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
344 [Unix only] standard input/output
346 The default device is @code{vc} in graphical mode and @code{stdio} in
349 This option can be used several times to simulate up to 4 serials
353 Redirect the monitor to host device @var{dev} (same devices as the
355 The default device is @code{vc} in graphical mode and @code{stdio} in
359 Wait gdb connection to port 1234 (@xref{gdb_usage}).
361 Change gdb connection port.
363 Do not start CPU at startup (you must type 'c' in the monitor).
365 Output log in /tmp/qemu.log
366 @item -hdachs c,h,s,[,t]
367 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
368 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
369 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
370 all thoses parameters. This option is useful for old MS-DOS disk
373 Simulate an ISA-only system (default is PCI system).
375 Simulate a standard VGA card with Bochs VBE extensions (default is
376 Cirrus Logic GD5446 PCI VGA)
378 Start right away with a saved state (@code{loadvm} in monitor)
387 During the graphical emulation, you can use the following keys:
393 Switch to virtual console 'n'. Standard console mappings are:
396 Target system display
404 Toggle mouse and keyboard grab.
407 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
408 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
410 During emulation, if you are using the @option{-nographic} option, use
411 @key{Ctrl-a h} to get terminal commands:
419 Save disk data back to file (if -snapshot)
421 Send break (magic sysrq in Linux)
423 Switch between console and monitor
432 @settitle QEMU System Emulator
435 The HTML documentation of QEMU for more precise information and Linux
436 user mode emulator invocation.
448 @section QEMU Monitor
450 The QEMU monitor is used to give complex commands to the QEMU
451 emulator. You can use it to:
456 Remove or insert removable medias images
457 (such as CD-ROM or floppies)
460 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
463 @item Inspect the VM state without an external debugger.
469 The following commands are available:
473 @item help or ? [cmd]
474 Show the help for all commands or just for command @var{cmd}.
477 Commit changes to the disk images (if -snapshot is used)
479 @item info subcommand
480 show various information about the system state
484 show the network state
486 show the block devices
488 show the cpu registers
490 show the command line history
496 @item eject [-f] device
497 Eject a removable media (use -f to force it).
499 @item change device filename
500 Change a removable media.
502 @item screendump filename
503 Save screen into PPM image @var{filename}.
505 @item log item1[,...]
506 Activate logging of the specified items to @file{/tmp/qemu.log}.
508 @item savevm filename
509 Save the whole virtual machine state to @var{filename}.
511 @item loadvm filename
512 Restore the whole virtual machine state from @var{filename}.
520 @item gdbserver [port]
521 Start gdbserver session (default port=1234)
524 Virtual memory dump starting at @var{addr}.
527 Physical memory dump starting at @var{addr}.
529 @var{fmt} is a format which tells the command how to format the
530 data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
534 is the number of items to be dumped.
537 can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
538 c (char) or i (asm instruction).
541 can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
542 @code{h} or @code{w} can be specified with the @code{i} format to
543 respectively select 16 or 32 bit code instruction size.
550 Dump 10 instructions at the current instruction pointer:
555 0x90107065: lea 0x0(%esi,1),%esi
556 0x90107069: lea 0x0(%edi,1),%edi
558 0x90107071: jmp 0x90107080
566 Dump 80 16 bit values at the start of the video memory.
568 (qemu) xp/80hx 0xb8000
569 0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
570 0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
571 0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
572 0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
573 0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
574 0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
575 0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
576 0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
577 0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
578 0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
582 @item p or print/fmt expr
584 Print expression value. Only the @var{format} part of @var{fmt} is
589 Send @var{keys} to the emulator. Use @code{-} to press several keys
590 simultaneously. Example:
595 This command is useful to send keys that your graphical user interface
596 intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
604 @subsection Integer expressions
606 The monitor understands integers expressions for every integer
607 argument. You can use register names to get the value of specifics
608 CPU registers by prefixing them with @emph{$}.
613 Since version 0.6.1, QEMU supports many disk image formats, including
614 growable disk images (their size increase as non empty sectors are
615 written), compressed and encrypted disk images.
617 @subsection Quick start for disk image creation
619 You can create a disk image with the command:
621 qemu-img create myimage.img mysize
623 where @var{myimage.img} is the disk image filename and @var{mysize} is its
624 size in kilobytes. You can add an @code{M} suffix to give the size in
625 megabytes and a @code{G} suffix for gigabytes.
627 @xref{qemu_img_invocation} for more information.
629 @subsection Snapshot mode
631 If you use the option @option{-snapshot}, all disk images are
632 considered as read only. When sectors in written, they are written in
633 a temporary file created in @file{/tmp}. You can however force the
634 write back to the raw disk images by using the @code{commit} monitor
635 command (or @key{C-a s} in the serial console).
637 @node qemu_img_invocation
638 @subsection @code{qemu-img} Invocation
640 @include qemu-img.texi
642 @section Network emulation
644 QEMU simulates up to 6 networks cards (NE2000 boards). Each card can
645 be connected to a specific host network interface.
647 @subsection Using tun/tap network interface
649 This is the standard way to emulate network. QEMU adds a virtual
650 network device on your host (called @code{tun0}), and you can then
651 configure it as if it was a real ethernet card.
653 As an example, you can download the @file{linux-test-xxx.tar.gz}
654 archive and copy the script @file{qemu-ifup} in @file{/etc} and
655 configure properly @code{sudo} so that the command @code{ifconfig}
656 contained in @file{qemu-ifup} can be executed as root. You must verify
657 that your host kernel supports the TUN/TAP network interfaces: the
658 device @file{/dev/net/tun} must be present.
660 See @ref{direct_linux_boot} to have an example of network use with a
663 @subsection Using the user mode network stack
665 By using the option @option{-user-net} or if you have no tun/tap init
666 script, QEMU uses a completely user mode network stack (you don't need
667 root priviledge to use the virtual network). The virtual network
668 configuration is the following:
672 QEMU Virtual Machine <------> Firewall/DHCP server <-----> Internet
673 (10.0.2.x) | (10.0.2.2)
675 ----> DNS server (10.0.2.3)
677 ----> SMB server (10.0.2.4)
680 The QEMU VM behaves as if it was behind a firewall which blocks all
681 incoming connections. You can use a DHCP client to automatically
682 configure the network in the QEMU VM.
684 In order to check that the user mode network is working, you can ping
685 the address 10.0.2.2 and verify that you got an address in the range
686 10.0.2.x from the QEMU virtual DHCP server.
688 Note that @code{ping} is not supported reliably to the internet as it
689 would require root priviledges. It means you can only ping the local
692 When using the built-in TFTP server, the router is also the TFTP
695 When using the @option{-redir} option, TCP or UDP connections can be
696 redirected from the host to the guest. It allows for example to
697 redirect X11, telnet or SSH connections.
699 @node direct_linux_boot
700 @section Direct Linux Boot
702 This section explains how to launch a Linux kernel inside QEMU without
703 having to make a full bootable image. It is very useful for fast Linux
704 kernel testing. The QEMU network configuration is also explained.
708 Download the archive @file{linux-test-xxx.tar.gz} containing a Linux
709 kernel and a disk image.
711 @item Optional: If you want network support (for example to launch X11 examples), you
712 must copy the script @file{qemu-ifup} in @file{/etc} and configure
713 properly @code{sudo} so that the command @code{ifconfig} contained in
714 @file{qemu-ifup} can be executed as root. You must verify that your host
715 kernel supports the TUN/TAP network interfaces: the device
716 @file{/dev/net/tun} must be present.
718 When network is enabled, there is a virtual network connection between
719 the host kernel and the emulated kernel. The emulated kernel is seen
720 from the host kernel at IP address 172.20.0.2 and the host kernel is
721 seen from the emulated kernel at IP address 172.20.0.1.
723 @item Launch @code{qemu.sh}. You should have the following output:
727 Connected to host network interface: tun0
728 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
729 BIOS-provided physical RAM map:
730 BIOS-e801: 0000000000000000 - 000000000009f000 (usable)
731 BIOS-e801: 0000000000100000 - 0000000002000000 (usable)
732 32MB LOWMEM available.
733 On node 0 totalpages: 8192
737 Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe console=ttyS0
738 ide_setup: ide2=noprobe
739 ide_setup: ide3=noprobe
740 ide_setup: ide4=noprobe
741 ide_setup: ide5=noprobe
743 Detected 2399.621 MHz processor.
744 Console: colour EGA 80x25
745 Calibrating delay loop... 4744.80 BogoMIPS
746 Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, 0k highmem)
747 Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
748 Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
749 Mount cache hash table entries: 512 (order: 0, 4096 bytes)
750 Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
751 Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
752 CPU: Intel Pentium Pro stepping 03
753 Checking 'hlt' instruction... OK.
754 POSIX conformance testing by UNIFIX
755 Linux NET4.0 for Linux 2.4
756 Based upon Swansea University Computer Society NET3.039
757 Initializing RT netlink socket
760 Journalled Block Device driver loaded
761 Detected PS/2 Mouse Port.
762 pty: 256 Unix98 ptys configured
763 Serial driver version 5.05c (2001-07-08) with no serial options enabled
764 ttyS00 at 0x03f8 (irq = 4) is a 16450
765 ne.c:v1.10 9/23/94 Donald Becker (becker@scyld.com)
766 Last modified Nov 1, 2000 by Paul Gortmaker
767 NE*000 ethercard probe at 0x300: 52 54 00 12 34 56
768 eth0: NE2000 found at 0x300, using IRQ 9.
769 RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
770 Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
771 ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
772 hda: QEMU HARDDISK, ATA DISK drive
773 ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
774 hda: attached ide-disk driver.
775 hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63
778 Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996
779 NET4: Linux TCP/IP 1.0 for NET4.0
780 IP Protocols: ICMP, UDP, TCP, IGMP
781 IP: routing cache hash table of 512 buckets, 4Kbytes
782 TCP: Hash tables configured (established 2048 bind 4096)
783 NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
784 EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
785 VFS: Mounted root (ext2 filesystem).
786 Freeing unused kernel memory: 64k freed
788 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
790 QEMU Linux test distribution (based on Redhat 9)
792 Type 'exit' to halt the system
798 Then you can play with the kernel inside the virtual serial console. You
799 can launch @code{ls} for example. Type @key{Ctrl-a h} to have an help
800 about the keys you can type inside the virtual serial console. In
801 particular, use @key{Ctrl-a x} to exit QEMU and use @key{Ctrl-a b} as
805 If the network is enabled, launch the script @file{/etc/linuxrc} in the
806 emulator (don't forget the leading dot):
811 Then enable X11 connections on your PC from the emulated Linux:
816 You can now launch @file{xterm} or @file{xlogo} and verify that you have
817 a real Virtual Linux system !
824 A 2.5.74 kernel is also included in the archive. Just
825 replace the bzImage in qemu.sh to try it.
828 qemu-fast creates a temporary file in @var{$QEMU_TMPDIR} (@file{/tmp} is the
829 default) containing all the simulated PC memory. If possible, try to use
830 a temporary directory using the tmpfs filesystem to avoid too many
831 unnecessary disk accesses.
834 In order to exit cleanly from qemu, you can do a @emph{shutdown} inside
835 qemu. qemu will automatically exit when the Linux shutdown is done.
838 You can boot slightly faster by disabling the probe of non present IDE
839 interfaces. To do so, add the following options on the kernel command
842 ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe
846 The example disk image is a modified version of the one made by Kevin
847 Lawton for the plex86 Project (@url{www.plex86.org}).
852 @section Linux Kernel Compilation
854 You can use any linux kernel with QEMU. However, if you want to use
855 @code{qemu-fast} to get maximum performances, you must use a modified
856 guest kernel. If you are using a 2.6 guest kernel, you can use
857 directly the patch @file{linux-2.6-qemu-fast.patch} made by Rusty
858 Russel available in the QEMU source archive. Otherwise, you can make the
859 following changes @emph{by hand} to the Linux kernel:
863 The kernel must be mapped at 0x90000000 (the default is
864 0xc0000000). You must modify only two lines in the kernel source:
866 In @file{include/asm/page.h}, replace
868 #define __PAGE_OFFSET (0xc0000000)
872 #define __PAGE_OFFSET (0x90000000)
875 And in @file{arch/i386/vmlinux.lds}, replace
877 . = 0xc0000000 + 0x100000;
881 . = 0x90000000 + 0x100000;
885 If you want to enable SMP (Symmetric Multi-Processing) support, you
886 must make the following change in @file{include/asm/fixmap.h}. Replace
888 #define FIXADDR_TOP (0xffffX000UL)
892 #define FIXADDR_TOP (0xa7ffX000UL)
894 (X is 'e' or 'f' depending on the kernel version). Although you can
895 use an SMP kernel with QEMU, it only supports one CPU.
898 If you are not using a 2.6 kernel as host kernel but if you use a target
899 2.6 kernel, you must also ensure that the 'HZ' define is set to 100
900 (1000 is the default) as QEMU cannot currently emulate timers at
901 frequencies greater than 100 Hz on host Linux systems < 2.6. In
902 @file{include/asm/param.h}, replace:
905 # define HZ 1000 /* Internal kernel timer frequency */
909 # define HZ 100 /* Internal kernel timer frequency */
914 The file config-2.x.x gives the configuration of the example kernels.
921 As you would do to make a real kernel. Then you can use with QEMU
922 exactly the same kernel as you would boot on your PC (in
923 @file{arch/i386/boot/bzImage}).
928 QEMU has a primitive support to work with gdb, so that you can do
929 'Ctrl-C' while the virtual machine is running and inspect its state.
931 In order to use gdb, launch qemu with the '-s' option. It will wait for a
934 > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
935 Connected to host network interface: tun0
936 Waiting gdb connection on port 1234
939 Then launch gdb on the 'vmlinux' executable:
944 In gdb, connect to QEMU:
946 (gdb) target remote localhost:1234
949 Then you can use gdb normally. For example, type 'c' to launch the kernel:
954 Here are some useful tips in order to use gdb on system code:
958 Use @code{info reg} to display all the CPU registers.
960 Use @code{x/10i $eip} to display the code at the PC position.
962 Use @code{set architecture i8086} to dump 16 bit code. Then use
963 @code{x/10i $cs*16+*eip} to dump the code at the PC position.
966 @section Target OS specific information
970 To have access to SVGA graphic modes under X11, use the @code{vesa} or
971 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
972 color depth in the guest and the host OS.
974 When using a 2.6 guest Linux kernel, you should add the option
975 @code{clock=pit} on the kernel command line because the 2.6 Linux
976 kernels make very strict real time clock checks by default that QEMU
977 cannot simulate exactly.
981 If you have a slow host, using Windows 95 is better as it gives the
982 best speed. Windows 2000 is also a good choice.
984 @subsubsection SVGA graphic modes support
986 QEMU emulates a Cirrus Logic GD5446 Video
987 card. All Windows versions starting from Windows 95 should recognize
988 and use this graphic card. For optimal performances, use 16 bit color
989 depth in the guest and the host OS.
991 @subsubsection CPU usage reduction
993 Windows 9x does not correctly use the CPU HLT
994 instruction. The result is that it takes host CPU cycles even when
995 idle. You can install the utility from
996 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
997 problem. Note that no such tool is needed for NT, 2000 or XP.
999 @subsubsection Windows 2000 disk full problems
1001 Currently (release 0.6.0) QEMU has a bug which gives a @code{disk
1002 full} error during installation of some releases of Windows 2000. The
1003 workaround is to stop QEMU as soon as you notice that your disk image
1004 size is growing too fast (monitor it with @code{ls -ls}). Then
1005 relaunch QEMU to continue the installation. If you still experience
1006 the problem, relaunch QEMU again.
1008 Future QEMU releases are likely to correct this bug.
1010 @subsubsection Windows XP security problems
1012 Some releases of Windows XP install correctly but give a security
1015 A problem is preventing Windows from accurately checking the
1016 license for this computer. Error code: 0x800703e6.
1018 The only known workaround is to boot in Safe mode
1019 without networking support.
1021 Future QEMU releases are likely to correct this bug.
1023 @subsection MS-DOS and FreeDOS
1025 @subsubsection CPU usage reduction
1027 DOS does not correctly use the CPU HLT instruction. The result is that
1028 it takes host CPU cycles even when idle. You can install the utility
1029 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1032 @chapter QEMU PowerPC System emulator invocation
1034 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1035 or PowerMac PowerPC system.
1037 QEMU emulates the following PowerMac peripherials:
1043 PCI VGA compatible card with VESA Bochs Extensions
1045 2 PMAC IDE interfaces with hard disk and CD-ROM support
1051 VIA-CUDA with ADB keyboard and mouse.
1054 QEMU emulates the following PREP peripherials:
1060 PCI VGA compatible card with VESA Bochs Extensions
1062 2 IDE interfaces with hard disk and CD-ROM support
1066 NE2000 network adapters
1070 PREP Non Volatile RAM
1072 PC compatible keyboard and mouse.
1075 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1076 @url{http://site.voila.fr/jmayer/OpenHackWare/index.htm}.
1078 You can read the qemu PC system emulation chapter to have more
1079 informations about QEMU usage.
1081 @c man begin OPTIONS
1083 The following options are specific to the PowerPC emulation:
1088 Simulate a PREP system (default is PowerMAC)
1090 @item -g WxH[xDEPTH]
1092 Set the initial VGA graphic mode. The default is 800x600x15.
1099 More information is available at
1100 @url{http://jocelyn.mayer.free.fr/qemu-ppc/}.
1102 @chapter Sparc System emulator invocation
1104 Use the executable @file{qemu-system-sparc} to simulate a JavaStation
1105 (sun4m architecture). The emulation is far from complete.
1107 QEMU emulates the following sun4m peripherials:
1115 Lance (Am7990) Ethernet
1117 Non Volatile RAM M48T08
1119 Slave I/O: timers, interrupt controllers, Zilog serial ports
1122 QEMU uses the Proll, a PROM replacement available at
1123 @url{http://people.redhat.com/zaitcev/linux/}.
1125 @chapter QEMU User space emulator invocation
1127 @section Quick Start
1129 In order to launch a Linux process, QEMU needs the process executable
1130 itself and all the target (x86) dynamic libraries used by it.
1134 @item On x86, you can just try to launch any process by using the native
1138 qemu-i386 -L / /bin/ls
1141 @code{-L /} tells that the x86 dynamic linker must be searched with a
1144 @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):
1147 qemu-i386 -L / qemu-i386 -L / /bin/ls
1150 @item On non x86 CPUs, you need first to download at least an x86 glibc
1151 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
1152 @code{LD_LIBRARY_PATH} is not set:
1155 unset LD_LIBRARY_PATH
1158 Then you can launch the precompiled @file{ls} x86 executable:
1161 qemu-i386 tests/i386/ls
1163 You can look at @file{qemu-binfmt-conf.sh} so that
1164 QEMU is automatically launched by the Linux kernel when you try to
1165 launch x86 executables. It requires the @code{binfmt_misc} module in the
1168 @item The x86 version of QEMU is also included. You can try weird things such as:
1170 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386
1175 @section Wine launch
1179 @item Ensure that you have a working QEMU with the x86 glibc
1180 distribution (see previous section). In order to verify it, you must be
1184 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
1187 @item Download the binary x86 Wine install
1188 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
1190 @item Configure Wine on your account. Look at the provided script
1191 @file{/usr/local/qemu-i386/bin/wine-conf.sh}. Your previous
1192 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
1194 @item Then you can try the example @file{putty.exe}:
1197 qemu-i386 /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
1202 @section Command line options
1205 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
1212 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
1214 Set the x86 stack size in bytes (default=524288)
1221 Activate log (logfile=/tmp/qemu.log)
1223 Act as if the host page size was 'pagesize' bytes
1227 @chapter Compilation from the sources
1231 Read the @file{README} which gives the related information.
1236 @item Install the current versions of MSYS and MinGW from
1237 @url{http://www.mingw.org/}. You can find detailed installation
1238 instructions in the download section and the FAQ.
1241 the MinGW development library of SDL 1.2.x
1242 (@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
1243 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
1244 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
1245 directory. Edit the @file{sdl-config} script so that it gives the
1246 correct SDL directory when invoked.
1248 @item Extract the current version of QEMU.
1250 @item Start the MSYS shell (file @file{msys.bat}).
1252 @item Change to the QEMU directory. Launch @file{./configure} and
1253 @file{make}. If you have problems using SDL, verify that
1254 @file{sdl-config} can be launched from the MSYS command line.
1256 @item You can install QEMU in @file{Program Files/Qemu} by typing
1257 @file{make install}. Don't forget to copy @file{SDL.dll} in
1258 @file{Program Files/Qemu}.
1262 @section Cross compilation for Windows with Linux
1266 Install the MinGW cross compilation tools available at
1267 @url{http://www.mingw.org/}.
1270 Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
1271 unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
1272 variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
1273 the QEMU configuration script.
1276 Configure QEMU for Windows cross compilation:
1278 ./configure --enable-mingw32
1280 If necessary, you can change the cross-prefix according to the prefix
1281 choosen for the MinGW tools with --cross-prefix. You can also use
1282 --prefix to set the Win32 install path.
1284 @item You can install QEMU in the installation directory by typing
1285 @file{make install}. Don't forget to copy @file{SDL.dll} in the
1286 installation directory.
1290 Note: Currently, Wine does not seem able to launch
1295 The Mac OS X patches are not fully merged in QEMU, so you should look
1296 at the QEMU mailing list archive to have all the necessary