gwj / at91sam9263 · Commits

Commit 1f673135acedadf942edb0c6c5238739313d718c

Authored by bellard
1 parent aa455485

doc update 


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@705 c046a42c-6fe2-441c-8c8c-71466251a162
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Showing 5 changed files with 1302 additions and 670 deletions
Makefile
  View file @1f67313
@@ -11,7 +11,7 @@ ifndef CONFIG_WIN32 @@ -11,7 +11,7 @@ ifndef CONFIG_WIN32
11 TOOLS=qemu-mkcow 11 TOOLS=qemu-mkcow
12 endif 12 endif
13 13
14 -all: dyngen$(EXESUF) $(TOOLS) qemu-doc.html qemu.1 14 +all: dyngen$(EXESUF) $(TOOLS) qemu-doc.html qemu-tech.html qemu.1
15 for d in $(TARGET_DIRS); do \ 15 for d in $(TARGET_DIRS); do \
16 make -C $$d $@ || exit 1 ; \ 16 make -C $$d $@ || exit 1 ; \
17 done 17 done
@@ -61,7 +61,7 @@ TAGS: @@ -61,7 +61,7 @@ TAGS:
61 etags *.[ch] tests/*.[ch] 61 etags *.[ch] tests/*.[ch]
62 62
63 # documentation 63 # documentation
64 -qemu-doc.html: qemu-doc.texi 64 +%.html: %.texi
65 texi2html -monolithic -number $< 65 texi2html -monolithic -number $<
66 66
67 qemu.1: qemu-doc.texi 67 qemu.1: qemu-doc.texi
@@ -2,7 +2,6 @@ short term: @@ -2,7 +2,6 @@ short term:
2 ---------- 2 ----------
3 - handle fast timers + add explicit clocks 3 - handle fast timers + add explicit clocks
4 - OS/2 install bug 4 - OS/2 install bug
5 -- win 95 install bug  
6 - handle Self Modifying Code even if modifying current TB (BE OS 5 install) 5 - handle Self Modifying Code even if modifying current TB (BE OS 5 install)
7 - physical memory cache (reduce qemu-fast address space size to about 32 MB) 6 - physical memory cache (reduce qemu-fast address space size to about 32 MB)
8 - better code fetch 7 - better code fetch
linux-2.6-qemu-fast.patch 0 → 100644
  View file @1f67313
  1 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/arch/i386/Kconfig .32324-linux-2.6.0.updated/arch/i386/Kconfig
  2 +--- .32324-linux-2.6.0/arch/i386/Kconfig 2003-10-09 18:02:48.000000000 +1000
  3 ++++ .32324-linux-2.6.0.updated/arch/i386/Kconfig 2003-12-26 16:46:49.000000000 +1100
  4 +@@ -307,6 +307,14 @@ config X86_GENERIC
  5 + when it has moderate overhead. This is intended for generic
  6 + distributions kernels.
  7 +
  8 ++config QEMU
  9 ++ bool "Kernel to run under QEMU"
  10 ++ depends on EXPERIMENTAL
  11 ++ help
  12 ++ Select this if you want to boot the kernel inside qemu-fast,
  13 ++ the non-mmu version of the x86 emulator. See
  14 ++ <http://fabrice.bellard.free.fr/qemu/>. Say N.
  15 ++
  16 + #
  17 + # Define implied options from the CPU selection here
  18 + #
  19 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/arch/i386/kernel/Makefile .32324-linux-2.6.0.updated/arch/i386/kernel/Makefile
  20 +--- .32324-linux-2.6.0/arch/i386/kernel/Makefile 2003-09-29 10:25:15.000000000 +1000
  21 ++++ .32324-linux-2.6.0.updated/arch/i386/kernel/Makefile 2003-12-26 16:46:49.000000000 +1100
  22 +@@ -46,12 +46,14 @@ quiet_cmd_syscall = SYSCALL $@
  23 + cmd_syscall = $(CC) -nostdlib $(SYSCFLAGS_$(@F)) \
  24 + -Wl,-T,$(filter-out FORCE,$^) -o $@
  25 +
  26 ++export AFLAGS_vsyscall.lds.o += -P -C -U$(ARCH)
  27 ++
  28 + vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1
  29 + SYSCFLAGS_vsyscall-sysenter.so = $(vsyscall-flags)
  30 + SYSCFLAGS_vsyscall-int80.so = $(vsyscall-flags)
  31 +
  32 + $(obj)/vsyscall-int80.so $(obj)/vsyscall-sysenter.so: \
  33 +-$(obj)/vsyscall-%.so: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
  34 ++$(obj)/vsyscall-%.so: $(src)/vsyscall.lds.s $(obj)/vsyscall-%.o FORCE
  35 + $(call if_changed,syscall)
  36 +
  37 + # We also create a special relocatable object that should mirror the symbol
  38 +@@ -62,5 +64,5 @@ $(obj)/built-in.o: $(obj)/vsyscall-syms.
  39 + $(obj)/built-in.o: ld_flags += -R $(obj)/vsyscall-syms.o
  40 +
  41 + SYSCFLAGS_vsyscall-syms.o = -r
  42 +-$(obj)/vsyscall-syms.o: $(src)/vsyscall.lds $(obj)/vsyscall-sysenter.o FORCE
  43 ++$(obj)/vsyscall-syms.o: $(src)/vsyscall.lds.s $(obj)/vsyscall-sysenter.o FORCE
  44 + $(call if_changed,syscall)
  45 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/arch/i386/kernel/vmlinux.lds.S .32324-linux-2.6.0.updated/arch/i386/kernel/vmlinux.lds.S
  46 +--- .32324-linux-2.6.0/arch/i386/kernel/vmlinux.lds.S 2003-09-22 10:27:28.000000000 +1000
  47 ++++ .32324-linux-2.6.0.updated/arch/i386/kernel/vmlinux.lds.S 2003-12-26 16:46:49.000000000 +1100
  48 +@@ -3,6 +3,7 @@
  49 + */
  50 +
  51 + #include <asm-generic/vmlinux.lds.h>
  52 ++#include <asm/page.h>
  53 +
  54 + OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
  55 + OUTPUT_ARCH(i386)
  56 +@@ -10,7 +11,7 @@ ENTRY(startup_32)
  57 + jiffies = jiffies_64;
  58 + SECTIONS
  59 + {
  60 +- . = 0xC0000000 + 0x100000;
  61 ++ . = __PAGE_OFFSET + 0x100000;
  62 + /* read-only */
  63 + _text = .; /* Text and read-only data */
  64 + .text : {
  65 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/arch/i386/kernel/vsyscall.lds .32324-linux-2.6.0.updated/arch/i386/kernel/vsyscall.lds
  66 +--- .32324-linux-2.6.0/arch/i386/kernel/vsyscall.lds 2003-09-22 10:07:26.000000000 +1000
  67 ++++ .32324-linux-2.6.0.updated/arch/i386/kernel/vsyscall.lds 1970-01-01 10:00:00.000000000 +1000
  68 +@@ -1,67 +0,0 @@
  69 +-/*
  70 +- * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
  71 +- * object prelinked to its virtual address, and with only one read-only
  72 +- * segment (that fits in one page). This script controls its layout.
  73 +- */
  74 +-
  75 +-/* This must match <asm/fixmap.h>. */
  76 +-VSYSCALL_BASE = 0xffffe000;
  77 +-
  78 +-SECTIONS
  79 +-{
  80 +- . = VSYSCALL_BASE + SIZEOF_HEADERS;
  81 +-
  82 +- .hash : { *(.hash) } :text
  83 +- .dynsym : { *(.dynsym) }
  84 +- .dynstr : { *(.dynstr) }
  85 +- .gnu.version : { *(.gnu.version) }
  86 +- .gnu.version_d : { *(.gnu.version_d) }
  87 +- .gnu.version_r : { *(.gnu.version_r) }
  88 +-
  89 +- /* This linker script is used both with -r and with -shared.
  90 +- For the layouts to match, we need to skip more than enough
  91 +- space for the dynamic symbol table et al. If this amount
  92 +- is insufficient, ld -shared will barf. Just increase it here. */
  93 +- . = VSYSCALL_BASE + 0x400;
  94 +-
  95 +- .text : { *(.text) } :text =0x90909090
  96 +-
  97 +- .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
  98 +- .eh_frame : { KEEP (*(.eh_frame)) } :text
  99 +- .dynamic : { *(.dynamic) } :text :dynamic
  100 +- .useless : {
  101 +- *(.got.plt) *(.got)
  102 +- *(.data .data.* .gnu.linkonce.d.*)
  103 +- *(.dynbss)
  104 +- *(.bss .bss.* .gnu.linkonce.b.*)
  105 +- } :text
  106 +-}
  107 +-
  108 +-/*
  109 +- * We must supply the ELF program headers explicitly to get just one
  110 +- * PT_LOAD segment, and set the flags explicitly to make segments read-only.
  111 +- */
  112 +-PHDRS
  113 +-{
  114 +- text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
  115 +- dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
  116 +- eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
  117 +-}
  118 +-
  119 +-/*
  120 +- * This controls what symbols we export from the DSO.
  121 +- */
  122 +-VERSION
  123 +-{
  124 +- LINUX_2.5 {
  125 +- global:
  126 +- __kernel_vsyscall;
  127 +- __kernel_sigreturn;
  128 +- __kernel_rt_sigreturn;
  129 +-
  130 +- local: *;
  131 +- };
  132 +-}
  133 +-
  134 +-/* The ELF entry point can be used to set the AT_SYSINFO value. */
  135 +-ENTRY(__kernel_vsyscall);
  136 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/arch/i386/kernel/vsyscall.lds.S .32324-linux-2.6.0.updated/arch/i386/kernel/vsyscall.lds.S
  137 +--- .32324-linux-2.6.0/arch/i386/kernel/vsyscall.lds.S 1970-01-01 10:00:00.000000000 +1000
  138 ++++ .32324-linux-2.6.0.updated/arch/i386/kernel/vsyscall.lds.S 2003-12-26 16:46:49.000000000 +1100
  139 +@@ -0,0 +1,67 @@
  140 ++/*
  141 ++ * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
  142 ++ * object prelinked to its virtual address, and with only one read-only
  143 ++ * segment (that fits in one page). This script controls its layout.
  144 ++ */
  145 ++#include <asm/fixmap.h>
  146 ++
  147 ++VSYSCALL_BASE = __FIXADDR_TOP - 0x1000;
  148 ++
  149 ++SECTIONS
  150 ++{
  151 ++ . = VSYSCALL_BASE + SIZEOF_HEADERS;
  152 ++
  153 ++ .hash : { *(.hash) } :text
  154 ++ .dynsym : { *(.dynsym) }
  155 ++ .dynstr : { *(.dynstr) }
  156 ++ .gnu.version : { *(.gnu.version) }
  157 ++ .gnu.version_d : { *(.gnu.version_d) }
  158 ++ .gnu.version_r : { *(.gnu.version_r) }
  159 ++
  160 ++ /* This linker script is used both with -r and with -shared.
  161 ++ For the layouts to match, we need to skip more than enough
  162 ++ space for the dynamic symbol table et al. If this amount
  163 ++ is insufficient, ld -shared will barf. Just increase it here. */
  164 ++ . = VSYSCALL_BASE + 0x400;
  165 ++
  166 ++ .text : { *(.text) } :text =0x90909090
  167 ++
  168 ++ .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
  169 ++ .eh_frame : { KEEP (*(.eh_frame)) } :text
  170 ++ .dynamic : { *(.dynamic) } :text :dynamic
  171 ++ .useless : {
  172 ++ *(.got.plt) *(.got)
  173 ++ *(.data .data.* .gnu.linkonce.d.*)
  174 ++ *(.dynbss)
  175 ++ *(.bss .bss.* .gnu.linkonce.b.*)
  176 ++ } :text
  177 ++}
  178 ++
  179 ++/*
  180 ++ * We must supply the ELF program headers explicitly to get just one
  181 ++ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
  182 ++ */
  183 ++PHDRS
  184 ++{
  185 ++ text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
  186 ++ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
  187 ++ eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
  188 ++}
  189 ++
  190 ++/*
  191 ++ * This controls what symbols we export from the DSO.
  192 ++ */
  193 ++VERSION
  194 ++{
  195 ++ LINUX_2.5 {
  196 ++ global:
  197 ++ __kernel_vsyscall;
  198 ++ __kernel_sigreturn;
  199 ++ __kernel_rt_sigreturn;
  200 ++
  201 ++ local: *;
  202 ++ };
  203 ++}
  204 ++
  205 ++/* The ELF entry point can be used to set the AT_SYSINFO value. */
  206 ++ENTRY(__kernel_vsyscall);
  207 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/include/asm-i386/fixmap.h .32324-linux-2.6.0.updated/include/asm-i386/fixmap.h
  208 +--- .32324-linux-2.6.0/include/asm-i386/fixmap.h 2003-09-22 10:09:12.000000000 +1000
  209 ++++ .32324-linux-2.6.0.updated/include/asm-i386/fixmap.h 2003-12-26 16:46:49.000000000 +1100
  210 +@@ -14,6 +14,19 @@
  211 + #define _ASM_FIXMAP_H
  212 +
  213 + #include <linux/config.h>
  214 ++
  215 ++/* used by vmalloc.c, vsyscall.lds.S.
  216 ++ *
  217 ++ * Leave one empty page between vmalloc'ed areas and
  218 ++ * the start of the fixmap.
  219 ++ */
  220 ++#ifdef CONFIG_QEMU
  221 ++#define __FIXADDR_TOP 0xa7fff000
  222 ++#else
  223 ++#define __FIXADDR_TOP 0xfffff000
  224 ++#endif
  225 ++
  226 ++#ifndef __ASSEMBLY__
  227 + #include <linux/kernel.h>
  228 + #include <asm/acpi.h>
  229 + #include <asm/apicdef.h>
  230 +@@ -94,13 +107,8 @@ extern void __set_fixmap (enum fixed_add
  231 + #define clear_fixmap(idx) \
  232 + __set_fixmap(idx, 0, __pgprot(0))
  233 +
  234 +-/*
  235 +- * used by vmalloc.c.
  236 +- *
  237 +- * Leave one empty page between vmalloc'ed areas and
  238 +- * the start of the fixmap.
  239 +- */
  240 +-#define FIXADDR_TOP (0xfffff000UL)
  241 ++#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
  242 ++
  243 + #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
  244 + #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
  245 +
  246 +@@ -145,4 +153,5 @@ static inline unsigned long virt_to_fix(
  247 + return __virt_to_fix(vaddr);
  248 + }
  249 +
  250 ++#endif /* !__ASSEMBLY__ */
  251 + #endif
  252 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/include/asm-i386/page.h .32324-linux-2.6.0.updated/include/asm-i386/page.h
  253 +--- .32324-linux-2.6.0/include/asm-i386/page.h 2003-09-22 10:06:42.000000000 +1000
  254 ++++ .32324-linux-2.6.0.updated/include/asm-i386/page.h 2003-12-26 16:46:49.000000000 +1100
  255 +@@ -10,10 +10,10 @@
  256 + #define LARGE_PAGE_SIZE (1UL << PMD_SHIFT)
  257 +
  258 + #ifdef __KERNEL__
  259 +-#ifndef __ASSEMBLY__
  260 +-
  261 + #include <linux/config.h>
  262 +
  263 ++#ifndef __ASSEMBLY__
  264 ++
  265 + #ifdef CONFIG_X86_USE_3DNOW
  266 +
  267 + #include <asm/mmx.h>
  268 +@@ -115,12 +115,19 @@ static __inline__ int get_order(unsigned
  269 + #endif /* __ASSEMBLY__ */
  270 +
  271 + #ifdef __ASSEMBLY__
  272 ++#ifdef CONFIG_QEMU
  273 ++#define __PAGE_OFFSET (0x90000000)
  274 ++#else
  275 + #define __PAGE_OFFSET (0xC0000000)
  276 ++#endif /* QEMU */
  277 ++#else
  278 ++#ifdef CONFIG_QEMU
  279 ++#define __PAGE_OFFSET (0x90000000UL)
  280 + #else
  281 + #define __PAGE_OFFSET (0xC0000000UL)
  282 ++#endif /* QEMU */
  283 + #endif
  284 +
  285 +-
  286 + #define PAGE_OFFSET ((unsigned long)__PAGE_OFFSET)
  287 + #define VMALLOC_RESERVE ((unsigned long)__VMALLOC_RESERVE)
  288 + #define MAXMEM (-__PAGE_OFFSET-__VMALLOC_RESERVE)
  289 +diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .32324-linux-2.6.0/include/asm-i386/param.h .32324-linux-2.6.0.updated/include/asm-i386/param.h
  290 +--- .32324-linux-2.6.0/include/asm-i386/param.h 2003-09-21 17:26:06.000000000 +1000
  291 ++++ .32324-linux-2.6.0.updated/include/asm-i386/param.h 2003-12-26 16:46:49.000000000 +1100
  292 +@@ -2,7 +2,12 @@
  293 + #define _ASMi386_PARAM_H
  294 +
  295 + #ifdef __KERNEL__
  296 +-# define HZ 1000 /* Internal kernel timer frequency */
  297 ++# include <linux/config.h>
  298 ++# ifdef CONFIG_QEMU
  299 ++# define HZ 100
  300 ++# else
  301 ++# define HZ 1000 /* Internal kernel timer frequency */
  302 ++# endif
  303 + # define USER_HZ 100 /* .. some user interfaces are in "ticks" */
  304 + # define CLOCKS_PER_SEC (USER_HZ) /* like times() */
  305 + #endif
qemu-doc.texi
  View file @1f67313
1 \input texinfo @c -*- texinfo -*- 1 \input texinfo @c -*- texinfo -*-
2 2
3 @iftex 3 @iftex
4 -@settitle QEMU CPU Emulator Reference Documentation 4 +@settitle QEMU CPU Emulator User Documentation
5 @titlepage 5 @titlepage
6 @sp 7 6 @sp 7
7 -@center @titlefont{QEMU CPU Emulator Reference Documentation} 7 +@center @titlefont{QEMU CPU Emulator User Documentation}
8 @sp 3 8 @sp 3
9 @end titlepage 9 @end titlepage
10 @end iftex 10 @end iftex
@@ -13,126 +13,39 @@ @@ -13,126 +13,39 @@
13 13
14 @section Features 14 @section Features
15 15
16 -QEMU is a FAST! processor emulator. By using dynamic translation it  
17 -achieves a reasonnable speed while being easy to port on new host  
18 -CPUs. 16 +QEMU is a FAST! processor emulator using dynamic translation to
  17 +achieve good emulation speed.
19 18
20 QEMU has two operating modes: 19 QEMU has two operating modes:
21 20
22 @itemize @minus 21 @itemize @minus
23 22
24 @item 23 @item
25 -User mode emulation. In this mode, QEMU can launch Linux processes  
26 -compiled for one CPU on another CPU. Linux system calls are converted  
27 -because of endianness and 32/64 bit mismatches. The Wine Windows API  
28 -emulator (@url{http://www.winehq.org}) and the DOSEMU DOS emulator  
29 -(@url{http://www.dosemu.org}) are the main targets for QEMU. 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 28
31 @item 29 @item
32 -Full system emulation. In this mode, QEMU emulates a full  
33 -system, including a processor and various peripherials. Currently, it  
34 -is only used to launch an x86 Linux kernel on an x86 Linux system. It  
35 -enables easier testing and debugging of system code. It can also be  
36 -used to provide virtual hosting of several virtual PCs on a single  
37 -server. 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.
38 34
39 @end itemize 35 @end itemize
40 36
41 -As QEMU requires no host kernel patches to run, it is very safe and 37 +As QEMU requires no host kernel driver to run, it is very safe and
42 easy to use. 38 easy to use.
43 39
44 -QEMU generic features: 40 +For system emulation, only the x86 PC emulator is currently
  41 +usable. The PowerPC system emulator is being developped.
45 42
46 -@itemize  
47 -  
48 -@item User space only or full system emulation.  
49 -  
50 -@item Using dynamic translation to native code for reasonnable speed.  
51 -  
52 -@item Working on x86 and PowerPC hosts. Being tested on ARM, Sparc32, Alpha and S390.  
53 -  
54 -@item Self-modifying code support.  
55 -  
56 -@item Precise exceptions support.  
57 -  
58 -@item The virtual CPU is a library (@code{libqemu}) which can be used  
59 -in other projects.  
60 -  
61 -@end itemize  
62 -  
63 -QEMU user mode emulation features:  
64 -@itemize  
65 -@item Generic Linux system call converter, including most ioctls.  
66 -  
67 -@item clone() emulation using native CPU clone() to use Linux scheduler for threads.  
68 -  
69 -@item Accurate signal handling by remapping host signals to target signals.  
70 -@end itemize  
71 -@end itemize  
72 -  
73 -QEMU full system emulation features:  
74 -@itemize  
75 -@item QEMU can either use a full software MMU for maximum portability or use the host system call mmap() to simulate the target MMU.  
76 -@end itemize  
77 -  
78 -@section x86 emulation  
79 -  
80 -QEMU x86 target features:  
81 -  
82 -@itemize  
83 -  
84 -@item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation.  
85 -LDT/GDT and IDT are emulated. VM86 mode is also supported to run DOSEMU.  
86 -  
87 -@item Support of host page sizes bigger than 4KB in user mode emulation.  
88 -  
89 -@item QEMU can emulate itself on x86.  
90 -  
91 -@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}.  
92 -It can be used to test other x86 virtual CPUs.  
93 -  
94 -@end itemize  
95 -  
96 -Current QEMU limitations:  
97 -  
98 -@itemize  
99 -  
100 -@item No SSE/MMX support (yet).  
101 -  
102 -@item No x86-64 support.  
103 -  
104 -@item IPC syscalls are missing.  
105 -  
106 -@item The x86 segment limits and access rights are not tested at every  
107 -memory access.  
108 -  
109 -@item On non x86 host CPUs, @code{double}s are used instead of the non standard  
110 -10 byte @code{long double}s of x86 for floating point emulation to get  
111 -maximum performances.  
112 -  
113 -@item Some priviledged instructions or behaviors are missing, especially for segment protection testing (yet).  
114 -  
115 -@end itemize  
116 -  
117 -@section ARM emulation  
118 -  
119 -@itemize  
120 -  
121 -@item ARM emulation can currently launch small programs while using the  
122 -generic dynamic code generation architecture of QEMU.  
123 -  
124 -@item No FPU support (yet).  
125 -  
126 -@item No automatic regression testing (yet).  
127 -  
128 -@end itemize  
129 -  
130 -@section SPARC emulation  
131 -  
132 -The SPARC emulation is currently in development. 43 +For user emulation, x86, PowerPC, ARM, and SPARC CPUs are supported.
133 44
134 @chapter Installation 45 @chapter Installation
135 46
  47 +@section Linux
  48 +
136 If you want to compile QEMU, please read the @file{README} which gives 49 If you want to compile QEMU, please read the @file{README} which gives
137 the related information. Otherwise just download the binary 50 the related information. Otherwise just download the binary
138 distribution (@file{qemu-XXX-i386.tar.gz}) and untar it as root in 51 distribution (@file{qemu-XXX-i386.tar.gz}) and untar it as root in
@@ -144,106 +57,69 @@ cd / @@ -144,106 +57,69 @@ cd /
144 tar zxvf /tmp/qemu-XXX-i386.tar.gz 57 tar zxvf /tmp/qemu-XXX-i386.tar.gz
145 @end example 58 @end example
146 59
147 -@chapter QEMU User space emulator invocation  
148 -  
149 -@section Quick Start  
150 -  
151 -In order to launch a Linux process, QEMU needs the process executable  
152 -itself and all the target (x86) dynamic libraries used by it.  
153 - 60 +@section Windows
  61 +w
154 @itemize 62 @itemize
  63 +@item Install the current versions of MSYS and MinGW from
  64 +@url{http://www.mingw.org/}. You can find detailed installation
  65 +instructions in the download section and the FAQ.
  66 +
  67 +@item Download
  68 +the MinGW development library of SDL 1.2.x
  69 +(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
  70 +@url{http://www.libsdl.org}. Unpack it in a temporary place, and
  71 +unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
  72 +directory. Edit the @file{sdl-config} script so that it gives the
  73 +correct SDL directory when invoked.
  74 +
  75 +@item Extract the current version of QEMU.
  76 +
  77 +@item Start the MSYS shell (file @file{msys.bat}).
155 78
156 -@item On x86, you can just try to launch any process by using the native  
157 -libraries:  
158 -  
159 -@example  
160 -qemu-i386 -L / /bin/ls  
161 -@end example  
162 -  
163 -@code{-L /} tells that the x86 dynamic linker must be searched with a  
164 -@file{/} prefix.  
165 -  
166 -@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):  
167 -  
168 -@example  
169 -qemu-i386 -L / qemu-i386 -L / /bin/ls  
170 -@end example  
171 -  
172 -@item On non x86 CPUs, you need first to download at least an x86 glibc  
173 -(@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that  
174 -@code{LD_LIBRARY_PATH} is not set:  
175 -  
176 -@example  
177 -unset LD_LIBRARY_PATH  
178 -@end example 79 +@item Change to the QEMU directory. Launch @file{./configure} and
  80 +@file{make}. If you have problems using SDL, verify that
  81 +@file{sdl-config} can be launched from the MSYS command line.
179 82
180 -Then you can launch the precompiled @file{ls} x86 executable:  
181 -  
182 -@example  
183 -qemu-i386 tests/i386/ls  
184 -@end example  
185 -You can look at @file{qemu-binfmt-conf.sh} so that  
186 -QEMU is automatically launched by the Linux kernel when you try to  
187 -launch x86 executables. It requires the @code{binfmt_misc} module in the  
188 -Linux kernel.  
189 -  
190 -@item The x86 version of QEMU is also included. You can try weird things such as:  
191 -@example  
192 -qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386  
193 -@end example 83 +@item You can install QEMU in @file{Program Files/Qemu} by typing
  84 +@file{make install}. Don't forget to copy @file{SDL.dll} in
  85 +@file{Program Files/Qemu}.
194 86
195 @end itemize 87 @end itemize
196 88
197 -@section Wine launch 89 +@section Cross compilation for Windows with Linux
198 90
199 @itemize 91 @itemize
  92 +@item
  93 +Install the MinGW cross compilation tools available at
  94 +@url{http://www.mingw.org/}.
200 95
201 -@item Ensure that you have a working QEMU with the x86 glibc  
202 -distribution (see previous section). In order to verify it, you must be  
203 -able to do: 96 +@item
  97 +Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
  98 +unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
  99 +variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
  100 +the QEMU configuration script.
204 101
  102 +@item
  103 +Configure QEMU for Windows cross compilation:
205 @example 104 @example
206 -qemu-i386 /usr/local/qemu-i386/bin/ls-i386 105 +./configure --enable-mingw32
207 @end example 106 @end example
  107 +If necessary, you can change the cross-prefix according to the prefix
  108 +choosen for the MinGW tools with --cross-prefix. You can also use
  109 +--prefix to set the Win32 install path.
208 110
209 -@item Download the binary x86 Wine install  
210 -(@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).  
211 -  
212 -@item Configure Wine on your account. Look at the provided script  
213 -@file{/usr/local/qemu-i386/bin/wine-conf.sh}. Your previous  
214 -@code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.  
215 -  
216 -@item Then you can try the example @file{putty.exe}:  
217 -  
218 -@example  
219 -qemu-i386 /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe  
220 -@end example 111 +@item You can install QEMU in the installation directory by typing
  112 +@file{make install}. Don't forget to copy @file{SDL.dll} in the
  113 +installation directory.
221 114
222 @end itemize 115 @end itemize
223 116
224 -@section Command line options 117 +Note: Currently, Wine does not seem able to launch
  118 +QEMU for Win32.
225 119
226 -@example  
227 -usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]  
228 -@end example 120 +@section Mac OS X
229 121
230 -@table @option  
231 -@item -h  
232 -Print the help  
233 -@item -L path  
234 -Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)  
235 -@item -s size  
236 -Set the x86 stack size in bytes (default=524288)  
237 -@end table  
238 -  
239 -Debug options:  
240 -  
241 -@table @option  
242 -@item -d  
243 -Activate log (logfile=/tmp/qemu.log)  
244 -@item -p pagesize  
245 -Act as if the host page size was 'pagesize' bytes  
246 -@end table 122 +Mac OS X is currently not supported.
247 123
248 @chapter QEMU System emulator invocation 124 @chapter QEMU System emulator invocation
249 125
@@ -251,9 +127,7 @@ Act as if the host page size was &#39;pagesize&#39; bytes @@ -251,9 +127,7 @@ Act as if the host page size was &#39;pagesize&#39; bytes
251 127
252 @c man begin DESCRIPTION 128 @c man begin DESCRIPTION
253 129
254 -The QEMU System emulator simulates a complete PC. It can either boot  
255 -directly a Linux kernel (without any BIOS or boot loader) or boot like a  
256 -real PC with the included BIOS. 130 +The QEMU System emulator simulates a complete PC.
257 131
258 In order to meet specific user needs, two versions of QEMU are 132 In order to meet specific user needs, two versions of QEMU are
259 available: 133 available:
@@ -282,18 +156,14 @@ VGA (hardware level, including all non standard modes) @@ -282,18 +156,14 @@ VGA (hardware level, including all non standard modes)
282 PS/2 mouse and keyboard 156 PS/2 mouse and keyboard
283 @item 157 @item
284 2 IDE interfaces with hard disk and CD-ROM support 158 2 IDE interfaces with hard disk and CD-ROM support
  159 +@item
  160 +Floppy disk
285 @item 161 @item
286 -NE2000 network adapter (port=0x300, irq=9) 162 +up to 6 NE2000 network adapters
287 @item 163 @item
288 Serial port 164 Serial port
289 @item 165 @item
290 Soundblaster 16 card 166 Soundblaster 16 card
291 -@item  
292 -PIC (interrupt controler)  
293 -@item  
294 -PIT (timers)  
295 -@item  
296 -CMOS memory  
297 @end itemize 167 @end itemize
298 168
299 @c man end 169 @c man end
@@ -308,157 +178,6 @@ qemu linux.img @@ -308,157 +178,6 @@ qemu linux.img
308 178
309 Linux should boot and give you a prompt. 179 Linux should boot and give you a prompt.
310 180
311 -@section Direct Linux Boot and Network emulation  
312 -  
313 -This section explains how to launch a Linux kernel inside QEMU without  
314 -having to make a full bootable image. It is very useful for fast Linux  
315 -kernel testing. The QEMU network configuration is also explained.  
316 -  
317 -@enumerate  
318 -@item  
319 -Download the archive @file{linux-test-xxx.tar.gz} containing a Linux  
320 -kernel and a disk image.  
321 -  
322 -@item Optional: If you want network support (for example to launch X11 examples), you  
323 -must copy the script @file{qemu-ifup} in @file{/etc} and configure  
324 -properly @code{sudo} so that the command @code{ifconfig} contained in  
325 -@file{qemu-ifup} can be executed as root. You must verify that your host  
326 -kernel supports the TUN/TAP network interfaces: the device  
327 -@file{/dev/net/tun} must be present.  
328 -  
329 -When network is enabled, there is a virtual network connection between  
330 -the host kernel and the emulated kernel. The emulated kernel is seen  
331 -from the host kernel at IP address 172.20.0.2 and the host kernel is  
332 -seen from the emulated kernel at IP address 172.20.0.1.  
333 -  
334 -@item Launch @code{qemu.sh}. You should have the following output:  
335 -  
336 -@example  
337 -> ./qemu.sh  
338 -Connected to host network interface: tun0  
339 -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  
340 -BIOS-provided physical RAM map:  
341 - BIOS-e801: 0000000000000000 - 000000000009f000 (usable)  
342 - BIOS-e801: 0000000000100000 - 0000000002000000 (usable)  
343 -32MB LOWMEM available.  
344 -On node 0 totalpages: 8192  
345 -zone(0): 4096 pages.  
346 -zone(1): 4096 pages.  
347 -zone(2): 0 pages.  
348 -Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe console=ttyS0  
349 -ide_setup: ide2=noprobe  
350 -ide_setup: ide3=noprobe  
351 -ide_setup: ide4=noprobe  
352 -ide_setup: ide5=noprobe  
353 -Initializing CPU#0  
354 -Detected 2399.621 MHz processor.  
355 -Console: colour EGA 80x25  
356 -Calibrating delay loop... 4744.80 BogoMIPS  
357 -Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, 0k highmem)  
358 -Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)  
359 -Inode cache hash table entries: 2048 (order: 2, 16384 bytes)  
360 -Mount cache hash table entries: 512 (order: 0, 4096 bytes)  
361 -Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)  
362 -Page-cache hash table entries: 8192 (order: 3, 32768 bytes)  
363 -CPU: Intel Pentium Pro stepping 03  
364 -Checking 'hlt' instruction... OK.  
365 -POSIX conformance testing by UNIFIX  
366 -Linux NET4.0 for Linux 2.4  
367 -Based upon Swansea University Computer Society NET3.039  
368 -Initializing RT netlink socket  
369 -apm: BIOS not found.  
370 -Starting kswapd  
371 -Journalled Block Device driver loaded  
372 -Detected PS/2 Mouse Port.  
373 -pty: 256 Unix98 ptys configured  
374 -Serial driver version 5.05c (2001-07-08) with no serial options enabled  
375 -ttyS00 at 0x03f8 (irq = 4) is a 16450  
376 -ne.c:v1.10 9/23/94 Donald Becker (becker@scyld.com)  
377 -Last modified Nov 1, 2000 by Paul Gortmaker  
378 -NE*000 ethercard probe at 0x300: 52 54 00 12 34 56  
379 -eth0: NE2000 found at 0x300, using IRQ 9.  
380 -RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize  
381 -Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4  
382 -ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx  
383 -hda: QEMU HARDDISK, ATA DISK drive  
384 -ide0 at 0x1f0-0x1f7,0x3f6 on irq 14  
385 -hda: attached ide-disk driver.  
386 -hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63  
387 -Partition check:  
388 - hda:  
389 -Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996  
390 -NET4: Linux TCP/IP 1.0 for NET4.0  
391 -IP Protocols: ICMP, UDP, TCP, IGMP  
392 -IP: routing cache hash table of 512 buckets, 4Kbytes  
393 -TCP: Hash tables configured (established 2048 bind 4096)  
394 -NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.  
395 -EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended  
396 -VFS: Mounted root (ext2 filesystem).  
397 -Freeing unused kernel memory: 64k freed  
398 -  
399 -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  
400 -  
401 -QEMU Linux test distribution (based on Redhat 9)  
402 -  
403 -Type 'exit' to halt the system  
404 -  
405 -sh-2.05b#  
406 -@end example  
407 -  
408 -@item  
409 -Then you can play with the kernel inside the virtual serial console. You  
410 -can launch @code{ls} for example. Type @key{Ctrl-a h} to have an help  
411 -about the keys you can type inside the virtual serial console. In  
412 -particular, use @key{Ctrl-a x} to exit QEMU and use @key{Ctrl-a b} as  
413 -the Magic SysRq key.  
414 -  
415 -@item  
416 -If the network is enabled, launch the script @file{/etc/linuxrc} in the  
417 -emulator (don't forget the leading dot):  
418 -@example  
419 -. /etc/linuxrc  
420 -@end example  
421 -  
422 -Then enable X11 connections on your PC from the emulated Linux:  
423 -@example  
424 -xhost +172.20.0.2  
425 -@end example  
426 -  
427 -You can now launch @file{xterm} or @file{xlogo} and verify that you have  
428 -a real Virtual Linux system !  
429 -  
430 -@end enumerate  
431 -  
432 -NOTES:  
433 -@enumerate  
434 -@item  
435 -A 2.5.74 kernel is also included in the archive. Just  
436 -replace the bzImage in qemu.sh to try it.  
437 -  
438 -@item  
439 -qemu creates a temporary file in @var{$QEMU_TMPDIR} (@file{/tmp} is the  
440 -default) containing all the simulated PC memory. If possible, try to use  
441 -a temporary directory using the tmpfs filesystem to avoid too many  
442 -unnecessary disk accesses.  
443 -  
444 -@item  
445 -In order to exit cleanly from qemu, you can do a @emph{shutdown} inside  
446 -qemu. qemu will automatically exit when the Linux shutdown is done.  
447 -  
448 -@item  
449 -You can boot slightly faster by disabling the probe of non present IDE  
450 -interfaces. To do so, add the following options on the kernel command  
451 -line:  
452 -@example  
453 -ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe  
454 -@end example  
455 -  
456 -@item  
457 -The example disk image is a modified version of the one made by Kevin  
458 -Lawton for the plex86 Project (@url{www.plex86.org}).  
459 -  
460 -@end enumerate  
461 -  
462 @section Invocation 181 @section Invocation
463 182
464 @example 183 @example
@@ -486,8 +205,8 @@ Use @var{file} as hard disk 0, 1, 2 or 3 image (@xref{disk_images}). @@ -486,8 +205,8 @@ Use @var{file} as hard disk 0, 1, 2 or 3 image (@xref{disk_images}).
486 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and 205 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
487 @option{-cdrom} at the same time). 206 @option{-cdrom} at the same time).
488 207
489 -@item -boot [a|b|c|d]  
490 -Boot on floppy (a, b), hard disk (c) or CD-ROM (d). Hard disk boot is 208 +@item -boot [a|c|d]
  209 +Boot on floppy (a), hard disk (c) or CD-ROM (d). Hard disk boot is
491 the default. 210 the default.
492 211
493 @item -snapshot 212 @item -snapshot
@@ -498,19 +217,9 @@ the write back by pressing @key{C-a s} (@xref{disk_images}). @@ -498,19 +217,9 @@ the write back by pressing @key{C-a s} (@xref{disk_images}).
498 @item -m megs 217 @item -m megs
499 Set virtual RAM size to @var{megs} megabytes. 218 Set virtual RAM size to @var{megs} megabytes.
500 219
501 -@item -n script  
502 -Set network init script [default=/etc/qemu-ifup]. This script is  
503 -launched to configure the host network interface (usually tun0)  
504 -corresponding to the virtual NE2000 card.  
505 -  
506 @item -initrd file 220 @item -initrd file
507 Use @var{file} as initial ram disk. 221 Use @var{file} as initial ram disk.
508 222
509 -@item -tun-fd fd  
510 -Assumes @var{fd} talks to tap/tun and use it. Read  
511 -@url{http://bellard.org/qemu/tetrinet.html} to have an example of its  
512 -use.  
513 -  
514 @item -nographic 223 @item -nographic
515 224
516 Normally, QEMU uses SDL to display the VGA output. With this option, 225 Normally, QEMU uses SDL to display the VGA output. With this option,
@@ -521,7 +230,35 @@ with a serial console. @@ -521,7 +230,35 @@ with a serial console.
521 230
522 @end table 231 @end table
523 232
524 -Linux boot specific (does not require a full PC boot with a BIOS): 233 +Network options:
  234 +
  235 +@table @option
  236 +
  237 +@item -n script
  238 +Set network init script [default=/etc/qemu-ifup]. This script is
  239 +launched to configure the host network interface (usually tun0)
  240 +corresponding to the virtual NE2000 card.
  241 +
  242 +@item nics n
  243 +Simulate @var{n} network interfaces (default=1).
  244 +
  245 +@item -macaddr addr
  246 +
  247 +Set the mac address of the first interface (the format is
  248 +aa:bb:cc:dd:ee:ff in hexa). The mac address is incremented for each
  249 +new network interface.
  250 +
  251 +@item -tun-fd fd1,...
  252 +Assumes @var{fd} talks to tap/tun and use it. Read
  253 +@url{http://bellard.org/qemu/tetrinet.html} to have an example of its
  254 +use.
  255 +
  256 +@end table
  257 +
  258 +Linux boot specific. When using this options, you can use a given
  259 +Linux kernel without installing it in the disk image. It can be useful
  260 +for easier testing of various kernels.
  261 +
525 @table @option 262 @table @option
526 263
527 @item -kernel bzImage 264 @item -kernel bzImage
@@ -545,7 +282,8 @@ Change gdb connection port. @@ -545,7 +282,8 @@ Change gdb connection port.
545 Output log in /tmp/qemu.log 282 Output log in /tmp/qemu.log
546 @end table 283 @end table
547 284
548 -During emulation, use @key{C-a h} to get terminal commands: 285 +During emulation, if you are using the serial console, use @key{C-a h}
  286 +to get terminal commands:
549 287
550 @table @key 288 @table @key
551 @item C-a h 289 @item C-a h
@@ -555,7 +293,9 @@ Exit emulatior @@ -555,7 +293,9 @@ Exit emulatior
555 @item C-a s 293 @item C-a s
556 Save disk data back to file (if -snapshot) 294 Save disk data back to file (if -snapshot)
557 @item C-a b 295 @item C-a b
558 -Send break (magic sysrq) 296 +Send break (magic sysrq in Linux)
  297 +@item C-a c
  298 +Switch between console and monitor
559 @item C-a C-a 299 @item C-a C-a
560 Send C-a 300 Send C-a
561 @end table 301 @end table
@@ -566,18 +306,165 @@ Send C-a @@ -566,18 +306,165 @@ Send C-a
566 @setfilename qemu 306 @setfilename qemu
567 @settitle QEMU System Emulator 307 @settitle QEMU System Emulator
568 308
569 -@c man begin SEEALSO  
570 -The HTML documentation of QEMU for more precise information and Linux  
571 -user mode emulator invocation.  
572 -@c man end 309 +@c man begin SEEALSO
  310 +The HTML documentation of QEMU for more precise information and Linux
  311 +user mode emulator invocation.
  312 +@c man end
  313 +
  314 +@c man begin AUTHOR
  315 +Fabrice Bellard
  316 +@c man end
  317 +
  318 +@end ignore
  319 +
  320 +@end ignore
  321 +
  322 +
  323 +@section QEMU Monitor
  324 +
  325 +The QEMU monitor is used to give complex commands to the QEMU
  326 +emulator. You can use it to:
  327 +
  328 +@itemize @minus
  329 +
  330 +@item
  331 +Remove or insert removable medias images
  332 +(such as CD-ROM or floppies)
  333 +
  334 +@item
  335 +Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
  336 +from a disk file.
  337 +
  338 +@item Inspect the VM state without an external debugger.
  339 +
  340 +@end itemize
  341 +
  342 +@subsection Commands
  343 +
  344 +The following commands are available:
  345 +
  346 +@table @option
  347 +
  348 +@item help or ? [cmd]
  349 +Show the help for all commands or just for command @var{cmd}.
  350 +
  351 +@item commit
  352 +Commit changes to the disk images (if -snapshot is used)
  353 +
  354 +@item info subcommand
  355 +show various information about the system state
  356 +
  357 +@table @option
  358 +@item info network
  359 +show the network state
  360 +@item info block
  361 +show the block devices
  362 +@item info registers
  363 +show the cpu registers
  364 +@item info history
  365 +show the command line history
  366 +@end table
  367 +
  368 +@item q or quit
  369 +Quit the emulator.
  370 +
  371 +@item eject [-f] device
  372 +Eject a removable media (use -f to force it).
  373 +
  374 +@item change device filename
  375 +Change a removable media.
  376 +
  377 +@item screendump filename
  378 +Save screen into PPM image @var{filename}.
  379 +
  380 +@item log item1[,...]
  381 +Activate logging of the specified items to @file{/tmp/qemu.log}.
  382 +
  383 +@item savevm filename
  384 +Save the whole virtual machine state to @var{filename}.
  385 +
  386 +@item loadvm filename
  387 +Restore the whole virtual machine state from @var{filename}.
  388 +
  389 +@item stop
  390 +Stop emulation.
  391 +
  392 +@item c or cont
  393 +Resume emulation.
  394 +
  395 +@item gdbserver [port]
  396 +Start gdbserver session (default port=1234)
  397 +
  398 +@item x/fmt addr
  399 +Virtual memory dump starting at @var{addr}.
  400 +
  401 +@item xp /fmt addr
  402 +Physical memory dump starting at @var{addr}.
  403 +
  404 +@var{fmt} is a format which tells the command how to format the
  405 +data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
  406 +
  407 +@table @var
  408 +@item count
  409 +is the number of items to be dumped.
  410 +
  411 +@item format
  412 +can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
  413 +c (char) or i (asm instruction).
  414 +
  415 +@item size
  416 +can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits)
  417 +
  418 +@end table
  419 +
  420 +Examples:
  421 +@itemize
  422 +@item
  423 +Dump 10 instructions at the current instruction pointer:
  424 +@example
  425 +(qemu) x/10i $eip
  426 +0x90107063: ret
  427 +0x90107064: sti
  428 +0x90107065: lea 0x0(%esi,1),%esi
  429 +0x90107069: lea 0x0(%edi,1),%edi
  430 +0x90107070: ret
  431 +0x90107071: jmp 0x90107080
  432 +0x90107073: nop
  433 +0x90107074: nop
  434 +0x90107075: nop
  435 +0x90107076: nop
  436 +@end example
  437 +
  438 +@item
  439 +Dump 80 16 bit values at the start of the video memory.
  440 +@example
  441 +(qemu) xp/80hx 0xb8000
  442 +0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
  443 +0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
  444 +0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
  445 +0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
  446 +0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
  447 +0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
  448 +0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
  449 +0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
  450 +0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
  451 +0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
  452 +@end example
  453 +@end itemize
  454 +
  455 +@item p or print/fmt expr
  456 +
  457 +Print expression value. Only the @var{format} part of @var{fmt} is
  458 +used.
573 459
574 -@c man begin AUTHOR  
575 -Fabrice Bellard  
576 -@c man end 460 +@end table
577 461
578 -@end ignore 462 +@subsection Integer expressions
  463 +
  464 +The monitor understands integers expressions for every integer
  465 +argument. You can use register names to get the value of specifics
  466 +CPU registers by prefixing them with @emph{$}.
579 467
580 -@end ignore  
581 @node disk_images 468 @node disk_images
582 @section Disk Images 469 @section Disk Images
583 470
@@ -649,13 +536,166 @@ Since holes are used, the displayed size of the COW disk image is not @@ -649,13 +536,166 @@ Since holes are used, the displayed size of the COW disk image is not
649 the real one. To know it, use the @code{ls -ls} command. 536 the real one. To know it, use the @code{ls -ls} command.
650 @end enumerate 537 @end enumerate
651 538
  539 +@section Direct Linux Boot and Network emulation
  540 +
  541 +This section explains how to launch a Linux kernel inside QEMU without
  542 +having to make a full bootable image. It is very useful for fast Linux
  543 +kernel testing. The QEMU network configuration is also explained.
  544 +
  545 +@enumerate
  546 +@item
  547 +Download the archive @file{linux-test-xxx.tar.gz} containing a Linux
  548 +kernel and a disk image.
  549 +
  550 +@item Optional: If you want network support (for example to launch X11 examples), you
  551 +must copy the script @file{qemu-ifup} in @file{/etc} and configure
  552 +properly @code{sudo} so that the command @code{ifconfig} contained in
  553 +@file{qemu-ifup} can be executed as root. You must verify that your host
  554 +kernel supports the TUN/TAP network interfaces: the device
  555 +@file{/dev/net/tun} must be present.
  556 +
  557 +When network is enabled, there is a virtual network connection between
  558 +the host kernel and the emulated kernel. The emulated kernel is seen
  559 +from the host kernel at IP address 172.20.0.2 and the host kernel is
  560 +seen from the emulated kernel at IP address 172.20.0.1.
  561 +
  562 +@item Launch @code{qemu.sh}. You should have the following output:
  563 +
  564 +@example
  565 +> ./qemu.sh
  566 +Connected to host network interface: tun0
  567 +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
  568 +BIOS-provided physical RAM map:
  569 + BIOS-e801: 0000000000000000 - 000000000009f000 (usable)
  570 + BIOS-e801: 0000000000100000 - 0000000002000000 (usable)
  571 +32MB LOWMEM available.
  572 +On node 0 totalpages: 8192
  573 +zone(0): 4096 pages.
  574 +zone(1): 4096 pages.
  575 +zone(2): 0 pages.
  576 +Kernel command line: root=/dev/hda sb=0x220,5,1,5 ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe console=ttyS0
  577 +ide_setup: ide2=noprobe
  578 +ide_setup: ide3=noprobe
  579 +ide_setup: ide4=noprobe
  580 +ide_setup: ide5=noprobe
  581 +Initializing CPU#0
  582 +Detected 2399.621 MHz processor.
  583 +Console: colour EGA 80x25
  584 +Calibrating delay loop... 4744.80 BogoMIPS
  585 +Memory: 28872k/32768k available (1210k kernel code, 3508k reserved, 266k data, 64k init, 0k highmem)
  586 +Dentry cache hash table entries: 4096 (order: 3, 32768 bytes)
  587 +Inode cache hash table entries: 2048 (order: 2, 16384 bytes)
  588 +Mount cache hash table entries: 512 (order: 0, 4096 bytes)
  589 +Buffer-cache hash table entries: 1024 (order: 0, 4096 bytes)
  590 +Page-cache hash table entries: 8192 (order: 3, 32768 bytes)
  591 +CPU: Intel Pentium Pro stepping 03
  592 +Checking 'hlt' instruction... OK.
  593 +POSIX conformance testing by UNIFIX
  594 +Linux NET4.0 for Linux 2.4
  595 +Based upon Swansea University Computer Society NET3.039
  596 +Initializing RT netlink socket
  597 +apm: BIOS not found.
  598 +Starting kswapd
  599 +Journalled Block Device driver loaded
  600 +Detected PS/2 Mouse Port.
  601 +pty: 256 Unix98 ptys configured
  602 +Serial driver version 5.05c (2001-07-08) with no serial options enabled
  603 +ttyS00 at 0x03f8 (irq = 4) is a 16450
  604 +ne.c:v1.10 9/23/94 Donald Becker (becker@scyld.com)
  605 +Last modified Nov 1, 2000 by Paul Gortmaker
  606 +NE*000 ethercard probe at 0x300: 52 54 00 12 34 56
  607 +eth0: NE2000 found at 0x300, using IRQ 9.
  608 +RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
  609 +Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
  610 +ide: Assuming 50MHz system bus speed for PIO modes; override with idebus=xx
  611 +hda: QEMU HARDDISK, ATA DISK drive
  612 +ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
  613 +hda: attached ide-disk driver.
  614 +hda: 20480 sectors (10 MB) w/256KiB Cache, CHS=20/16/63
  615 +Partition check:
  616 + hda:
  617 +Soundblaster audio driver Copyright (C) by Hannu Savolainen 1993-1996
  618 +NET4: Linux TCP/IP 1.0 for NET4.0
  619 +IP Protocols: ICMP, UDP, TCP, IGMP
  620 +IP: routing cache hash table of 512 buckets, 4Kbytes
  621 +TCP: Hash tables configured (established 2048 bind 4096)
  622 +NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
  623 +EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
  624 +VFS: Mounted root (ext2 filesystem).
  625 +Freeing unused kernel memory: 64k freed
  626 +
  627 +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
  628 +
  629 +QEMU Linux test distribution (based on Redhat 9)
  630 +
  631 +Type 'exit' to halt the system
  632 +
  633 +sh-2.05b#
  634 +@end example
  635 +
  636 +@item
  637 +Then you can play with the kernel inside the virtual serial console. You
  638 +can launch @code{ls} for example. Type @key{Ctrl-a h} to have an help
  639 +about the keys you can type inside the virtual serial console. In
  640 +particular, use @key{Ctrl-a x} to exit QEMU and use @key{Ctrl-a b} as
  641 +the Magic SysRq key.
  642 +
  643 +@item
  644 +If the network is enabled, launch the script @file{/etc/linuxrc} in the
  645 +emulator (don't forget the leading dot):
  646 +@example
  647 +. /etc/linuxrc
  648 +@end example
  649 +
  650 +Then enable X11 connections on your PC from the emulated Linux:
  651 +@example
  652 +xhost +172.20.0.2
  653 +@end example
  654 +
  655 +You can now launch @file{xterm} or @file{xlogo} and verify that you have
  656 +a real Virtual Linux system !
  657 +
  658 +@end enumerate
  659 +
  660 +NOTES:
  661 +@enumerate
  662 +@item
  663 +A 2.5.74 kernel is also included in the archive. Just
  664 +replace the bzImage in qemu.sh to try it.
  665 +
  666 +@item
  667 +qemu-fast creates a temporary file in @var{$QEMU_TMPDIR} (@file{/tmp} is the
  668 +default) containing all the simulated PC memory. If possible, try to use
  669 +a temporary directory using the tmpfs filesystem to avoid too many
  670 +unnecessary disk accesses.
  671 +
  672 +@item
  673 +In order to exit cleanly from qemu, you can do a @emph{shutdown} inside
  674 +qemu. qemu will automatically exit when the Linux shutdown is done.
  675 +
  676 +@item
  677 +You can boot slightly faster by disabling the probe of non present IDE
  678 +interfaces. To do so, add the following options on the kernel command
  679 +line:
  680 +@example
  681 +ide1=noprobe ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe
  682 +@end example
  683 +
  684 +@item
  685 +The example disk image is a modified version of the one made by Kevin
  686 +Lawton for the plex86 Project (@url{www.plex86.org}).
  687 +
  688 +@end enumerate
  689 +
652 @node linux_compile 690 @node linux_compile
653 @section Linux Kernel Compilation 691 @section Linux Kernel Compilation
654 692
655 You can use any linux kernel with QEMU. However, if you want to use 693 You can use any linux kernel with QEMU. However, if you want to use
656 -@code{qemu-fast} to get maximum performances, you should make the  
657 -following changes to the Linux kernel (only 2.4.x and 2.5.x were  
658 -tested): 694 +@code{qemu-fast} to get maximum performances, you must use a modified
  695 +guest kernel. If you are using a 2.6 guest kernel, you can use
  696 +directly the patch @file{linux-2.6-qemu-fast.patch} made by Rusty
  697 +Russel available in the QEMU source archive. Otherwise, you can make the
  698 +following changes @emph{by hand} to the Linux kernel:
659 699
660 @enumerate 700 @enumerate
661 @item 701 @item
@@ -694,10 +734,10 @@ by @@ -694,10 +734,10 @@ by
694 use an SMP kernel with QEMU, it only supports one CPU. 734 use an SMP kernel with QEMU, it only supports one CPU.
695 735
696 @item 736 @item
697 -If you are not using a 2.5 kernel as host kernel but if you use a target  
698 -2.5 kernel, you must also ensure that the 'HZ' define is set to 100 737 +If you are not using a 2.6 kernel as host kernel but if you use a target
  738 +2.6 kernel, you must also ensure that the 'HZ' define is set to 100
699 (1000 is the default) as QEMU cannot currently emulate timers at 739 (1000 is the default) as QEMU cannot currently emulate timers at
700 -frequencies greater than 100 Hz on host Linux systems < 2.5. In 740 +frequencies greater than 100 Hz on host Linux systems < 2.6. In
701 @file{include/asm/param.h}, replace: 741 @file{include/asm/param.h}, replace:
702 742
703 @example 743 @example
@@ -762,322 +802,104 @@ Use @code{set architecture i8086} to dump 16 bit code. Then use @@ -762,322 +802,104 @@ Use @code{set architecture i8086} to dump 16 bit code. Then use
762 @code{x/10i $cs*16+*eip} to dump the code at the PC position. 802 @code{x/10i $cs*16+*eip} to dump the code at the PC position.
763 @end enumerate 803 @end enumerate
764 804
765 -@chapter QEMU Internals  
766 -  
767 -@section QEMU compared to other emulators  
768 -  
769 -Like bochs [3], QEMU emulates an x86 CPU. But QEMU is much faster than  
770 -bochs as it uses dynamic compilation and because it uses the host MMU to  
771 -simulate the x86 MMU. The downside is that currently the emulation is  
772 -not as accurate as bochs (for example, you cannot currently run Windows  
773 -inside QEMU).  
774 -  
775 -Like Valgrind [2], QEMU does user space emulation and dynamic  
776 -translation. Valgrind is mainly a memory debugger while QEMU has no  
777 -support for it (QEMU could be used to detect out of bound memory  
778 -accesses as Valgrind, but it has no support to track uninitialised data  
779 -as Valgrind does). The Valgrind dynamic translator generates better code  
780 -than QEMU (in particular it does register allocation) but it is closely  
781 -tied to an x86 host and target and has no support for precise exceptions  
782 -and system emulation.  
783 -  
784 -EM86 [4] is the closest project to user space QEMU (and QEMU still uses  
785 -some of its code, in particular the ELF file loader). EM86 was limited  
786 -to an alpha host and used a proprietary and slow interpreter (the  
787 -interpreter part of the FX!32 Digital Win32 code translator [5]).  
788 -  
789 -TWIN [6] is a Windows API emulator like Wine. It is less accurate than  
790 -Wine but includes a protected mode x86 interpreter to launch x86 Windows  
791 -executables. Such an approach as greater potential because most of the  
792 -Windows API is executed natively but it is far more difficult to develop  
793 -because all the data structures and function parameters exchanged  
794 -between the API and the x86 code must be converted.  
795 -  
796 -User mode Linux [7] was the only solution before QEMU to launch a Linux  
797 -kernel as a process while not needing any host kernel patches. However,  
798 -user mode Linux requires heavy kernel patches while QEMU accepts  
799 -unpatched Linux kernels. It would be interesting to compare the  
800 -performance of the two approaches.  
801 -  
802 -The new Plex86 [8] PC virtualizer is done in the same spirit as the QEMU  
803 -system emulator. It requires a patched Linux kernel to work (you cannot  
804 -launch the same kernel on your PC), but the patches are really small. As  
805 -it is a PC virtualizer (no emulation is done except for some priveledged  
806 -instructions), it has the potential of being faster than QEMU. The  
807 -downside is that a complicated (and potentially unsafe) host kernel  
808 -patch is needed.  
809 -  
810 -@section Portable dynamic translation  
811 -  
812 -QEMU is a dynamic translator. When it first encounters a piece of code,  
813 -it converts it to the host instruction set. Usually dynamic translators  
814 -are very complicated and highly CPU dependent. QEMU uses some tricks  
815 -which make it relatively easily portable and simple while achieving good  
816 -performances.  
817 -  
818 -The basic idea is to split every x86 instruction into fewer simpler  
819 -instructions. Each simple instruction is implemented by a piece of C  
820 -code (see @file{op-i386.c}). Then a compile time tool (@file{dyngen})  
821 -takes the corresponding object file (@file{op-i386.o}) to generate a  
822 -dynamic code generator which concatenates the simple instructions to  
823 -build a function (see @file{op-i386.h:dyngen_code()}).  
824 -  
825 -In essence, the process is similar to [1], but more work is done at  
826 -compile time.  
827 -  
828 -A key idea to get optimal performances is that constant parameters can  
829 -be passed to the simple operations. For that purpose, dummy ELF  
830 -relocations are generated with gcc for each constant parameter. Then,  
831 -the tool (@file{dyngen}) can locate the relocations and generate the  
832 -appriopriate C code to resolve them when building the dynamic code.  
833 -  
834 -That way, QEMU is no more difficult to port than a dynamic linker.  
835 -  
836 -To go even faster, GCC static register variables are used to keep the  
837 -state of the virtual CPU.  
838 -  
839 -@section Register allocation  
840 -  
841 -Since QEMU uses fixed simple instructions, no efficient register  
842 -allocation can be done. However, because RISC CPUs have a lot of  
843 -register, most of the virtual CPU state can be put in registers without  
844 -doing complicated register allocation.  
845 -  
846 -@section Condition code optimisations  
847 -  
848 -Good CPU condition codes emulation (@code{EFLAGS} register on x86) is a  
849 -critical point to get good performances. QEMU uses lazy condition code  
850 -evaluation: instead of computing the condition codes after each x86  
851 -instruction, it just stores one operand (called @code{CC_SRC}), the  
852 -result (called @code{CC_DST}) and the type of operation (called  
853 -@code{CC_OP}).  
854 -  
855 -@code{CC_OP} is almost never explicitely set in the generated code  
856 -because it is known at translation time.  
857 -  
858 -In order to increase performances, a backward pass is performed on the  
859 -generated simple instructions (see  
860 -@code{translate-i386.c:optimize_flags()}). When it can be proved that  
861 -the condition codes are not needed by the next instructions, no  
862 -condition codes are computed at all.  
863 -  
864 -@section CPU state optimisations  
865 -  
866 -The x86 CPU has many internal states which change the way it evaluates  
867 -instructions. In order to achieve a good speed, the translation phase  
868 -considers that some state information of the virtual x86 CPU cannot  
869 -change in it. For example, if the SS, DS and ES segments have a zero  
870 -base, then the translator does not even generate an addition for the  
871 -segment base.  
872 -  
873 -[The FPU stack pointer register is not handled that way yet].  
874 -  
875 -@section Translation cache  
876 -  
877 -A 2MByte cache holds the most recently used translations. For  
878 -simplicity, it is completely flushed when it is full. A translation unit  
879 -contains just a single basic block (a block of x86 instructions  
880 -terminated by a jump or by a virtual CPU state change which the  
881 -translator cannot deduce statically).  
882 -  
883 -@section Direct block chaining  
884 -  
885 -After each translated basic block is executed, QEMU uses the simulated  
886 -Program Counter (PC) and other cpu state informations (such as the CS  
887 -segment base value) to find the next basic block.  
888 -  
889 -In order to accelerate the most common cases where the new simulated PC  
890 -is known, QEMU can patch a basic block so that it jumps directly to the  
891 -next one.  
892 -  
893 -The most portable code uses an indirect jump. An indirect jump makes it  
894 -easier to make the jump target modification atomic. On some  
895 -architectures (such as PowerPC), the @code{JUMP} opcode is directly  
896 -patched so that the block chaining has no overhead.  
897 -  
898 -@section Self-modifying code and translated code invalidation  
899 -  
900 -Self-modifying code is a special challenge in x86 emulation because no  
901 -instruction cache invalidation is signaled by the application when code  
902 -is modified.  
903 -  
904 -When translated code is generated for a basic block, the corresponding  
905 -host page is write protected if it is not already read-only (with the  
906 -system call @code{mprotect()}). Then, if a write access is done to the  
907 -page, Linux raises a SEGV signal. QEMU then invalidates all the  
908 -translated code in the page and enables write accesses to the page.  
909 -  
910 -Correct translated code invalidation is done efficiently by maintaining  
911 -a linked list of every translated block contained in a given page. Other  
912 -linked lists are also maintained to undo direct block chaining.  
913 -  
914 -Although the overhead of doing @code{mprotect()} calls is important,  
915 -most MSDOS programs can be emulated at reasonnable speed with QEMU and  
916 -DOSEMU.  
917 -  
918 -Note that QEMU also invalidates pages of translated code when it detects  
919 -that memory mappings are modified with @code{mmap()} or @code{munmap()}.  
920 -  
921 -@section Exception support  
922 -  
923 -longjmp() is used when an exception such as division by zero is  
924 -encountered.  
925 -  
926 -The host SIGSEGV and SIGBUS signal handlers are used to get invalid  
927 -memory accesses. The exact CPU state can be retrieved because all the  
928 -x86 registers are stored in fixed host registers. The simulated program  
929 -counter is found by retranslating the corresponding basic block and by  
930 -looking where the host program counter was at the exception point.  
931 -  
932 -The virtual CPU cannot retrieve the exact @code{EFLAGS} register because  
933 -in some cases it is not computed because of condition code  
934 -optimisations. It is not a big concern because the emulated code can  
935 -still be restarted in any cases.  
936 -  
937 -@section Linux system call translation  
938 -  
939 -QEMU includes a generic system call translator for Linux. It means that  
940 -the parameters of the system calls can be converted to fix the  
941 -endianness and 32/64 bit issues. The IOCTLs are converted with a generic  
942 -type description system (see @file{ioctls.h} and @file{thunk.c}). 805 +@chapter QEMU User space emulator invocation
943 806
944 -QEMU supports host CPUs which have pages bigger than 4KB. It records all  
945 -the mappings the process does and try to emulated the @code{mmap()}  
946 -system calls in cases where the host @code{mmap()} call would fail  
947 -because of bad page alignment. 807 +@section Quick Start
948 808
949 -@section Linux signals 809 +In order to launch a Linux process, QEMU needs the process executable
  810 +itself and all the target (x86) dynamic libraries used by it.
950 811
951 -Normal and real-time signals are queued along with their information  
952 -(@code{siginfo_t}) as it is done in the Linux kernel. Then an interrupt  
953 -request is done to the virtual CPU. When it is interrupted, one queued  
954 -signal is handled by generating a stack frame in the virtual CPU as the  
955 -Linux kernel does. The @code{sigreturn()} system call is emulated to return  
956 -from the virtual signal handler. 812 +@itemize
957 813
958 -Some signals (such as SIGALRM) directly come from the host. Other  
959 -signals are synthetized from the virtual CPU exceptions such as SIGFPE  
960 -when a division by zero is done (see @code{main.c:cpu_loop()}). 814 +@item On x86, you can just try to launch any process by using the native
  815 +libraries:
961 816
962 -The blocked signal mask is still handled by the host Linux kernel so  
963 -that most signal system calls can be redirected directly to the host  
964 -Linux kernel. Only the @code{sigaction()} and @code{sigreturn()} system  
965 -calls need to be fully emulated (see @file{signal.c}). 817 +@example
  818 +qemu-i386 -L / /bin/ls
  819 +@end example
966 820
967 -@section clone() system call and threads 821 +@code{-L /} tells that the x86 dynamic linker must be searched with a
  822 +@file{/} prefix.
968 823
969 -The Linux clone() system call is usually used to create a thread. QEMU  
970 -uses the host clone() system call so that real host threads are created  
971 -for each emulated thread. One virtual CPU instance is created for each  
972 -thread. 824 +@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):
973 825
974 -The virtual x86 CPU atomic operations are emulated with a global lock so  
975 -that their semantic is preserved. 826 +@example
  827 +qemu-i386 -L / qemu-i386 -L / /bin/ls
  828 +@end example
976 829
977 -Note that currently there are still some locking issues in QEMU. In  
978 -particular, the translated cache flush is not protected yet against  
979 -reentrancy. 830 +@item On non x86 CPUs, you need first to download at least an x86 glibc
  831 +(@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
  832 +@code{LD_LIBRARY_PATH} is not set:
980 833
981 -@section Self-virtualization 834 +@example
  835 +unset LD_LIBRARY_PATH
  836 +@end example
982 837
983 -QEMU was conceived so that ultimately it can emulate itself. Although  
984 -it is not very useful, it is an important test to show the power of the  
985 -emulator. 838 +Then you can launch the precompiled @file{ls} x86 executable:
986 839
987 -Achieving self-virtualization is not easy because there may be address  
988 -space conflicts. QEMU solves this problem by being an executable ELF  
989 -shared object as the ld-linux.so ELF interpreter. That way, it can be  
990 -relocated at load time. 840 +@example
  841 +qemu-i386 tests/i386/ls
  842 +@end example
  843 +You can look at @file{qemu-binfmt-conf.sh} so that
  844 +QEMU is automatically launched by the Linux kernel when you try to
  845 +launch x86 executables. It requires the @code{binfmt_misc} module in the
  846 +Linux kernel.
991 847
992 -@section MMU emulation 848 +@item The x86 version of QEMU is also included. You can try weird things such as:
  849 +@example
  850 +qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 /usr/local/qemu-i386/bin/ls-i386
  851 +@end example
993 852
994 -For system emulation, QEMU uses the mmap() system call to emulate the  
995 -target CPU MMU. It works as long the emulated OS does not use an area  
996 -reserved by the host OS (such as the area above 0xc0000000 on x86  
997 -Linux). 853 +@end itemize
998 854
999 -It is planned to add a slower but more precise MMU emulation  
1000 -with a software MMU. 855 +@section Wine launch
1001 856
1002 -@section Bibliography 857 +@itemize
1003 858
1004 -@table @asis 859 +@item Ensure that you have a working QEMU with the x86 glibc
  860 +distribution (see previous section). In order to verify it, you must be
  861 +able to do:
1005 862
1006 -@item [1]  
1007 -@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing  
1008 -direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio  
1009 -Riccardi. 863 +@example
  864 +qemu-i386 /usr/local/qemu-i386/bin/ls-i386
  865 +@end example
1010 866
1011 -@item [2]  
1012 -@url{http://developer.kde.org/~sewardj/}, Valgrind, an open-source  
1013 -memory debugger for x86-GNU/Linux, by Julian Seward. 867 +@item Download the binary x86 Wine install
  868 +(@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
1014 869
1015 -@item [3]  
1016 -@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,  
1017 -by Kevin Lawton et al. 870 +@item Configure Wine on your account. Look at the provided script
  871 +@file{/usr/local/qemu-i386/bin/wine-conf.sh}. Your previous
  872 +@code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
1018 873
1019 -@item [4]  
1020 -@url{http://www.cs.rose-hulman.edu/~donaldlf/em86/index.html}, the EM86  
1021 -x86 emulator on Alpha-Linux. 874 +@item Then you can try the example @file{putty.exe}:
1022 875
1023 -@item [5]  
1024 -@url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/full_papers/chernoff/chernoff.pdf},  
1025 -DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton  
1026 -Chernoff and Ray Hookway. 876 +@example
  877 +qemu-i386 /usr/local/qemu-i386/wine/bin/wine /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
  878 +@end example
1027 879
1028 -@item [6]  
1029 -@url{http://www.willows.com/}, Windows API library emulation from  
1030 -Willows Software. 880 +@end itemize
1031 881
1032 -@item [7]  
1033 -@url{http://user-mode-linux.sourceforge.net/},  
1034 -The User-mode Linux Kernel. 882 +@section Command line options
1035 883
1036 -@item [8]  
1037 -@url{http://www.plex86.org/},  
1038 -The new Plex86 project. 884 +@example
  885 +usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
  886 +@end example
1039 887
  888 +@table @option
  889 +@item -h
  890 +Print the help
  891 +@item -L path
  892 +Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
  893 +@item -s size
  894 +Set the x86 stack size in bytes (default=524288)
1040 @end table 895 @end table
1041 896
1042 -@chapter Regression Tests  
1043 -  
1044 -In the directory @file{tests/}, various interesting testing programs  
1045 -are available. There are used for regression testing.  
1046 -  
1047 -@section @file{test-i386}  
1048 -  
1049 -This program executes most of the 16 bit and 32 bit x86 instructions and  
1050 -generates a text output. It can be compared with the output obtained with  
1051 -a real CPU or another emulator. The target @code{make test} runs this  
1052 -program and a @code{diff} on the generated output.  
1053 -  
1054 -The Linux system call @code{modify_ldt()} is used to create x86 selectors  
1055 -to test some 16 bit addressing and 32 bit with segmentation cases.  
1056 -  
1057 -The Linux system call @code{vm86()} is used to test vm86 emulation.  
1058 -  
1059 -Various exceptions are raised to test most of the x86 user space  
1060 -exception reporting.  
1061 -  
1062 -@section @file{linux-test}  
1063 -  
1064 -This program tests various Linux system calls. It is used to verify  
1065 -that the system call parameters are correctly converted between target  
1066 -and host CPUs.  
1067 -  
1068 -@section @file{hello-i386}  
1069 -  
1070 -Very simple statically linked x86 program, just to test QEMU during a  
1071 -port to a new host CPU.  
1072 -  
1073 -@section @file{hello-arm}  
1074 -  
1075 -Very simple statically linked ARM program, just to test QEMU during a  
1076 -port to a new host CPU.  
1077 -  
1078 -@section @file{sha1} 897 +Debug options:
1079 898
1080 -It is a simple benchmark. Care must be taken to interpret the results  
1081 -because it mostly tests the ability of the virtual CPU to optimize the  
1082 -@code{rol} x86 instruction and the condition code computations. 899 +@table @option
  900 +@item -d
  901 +Activate log (logfile=/tmp/qemu.log)
  902 +@item -p pagesize
  903 +Act as if the host page size was 'pagesize' bytes
  904 +@end table
1083 905
qemu-tech.texi 0 → 100644
  View file @1f67313
  1 +\input texinfo @c -*- texinfo -*-
  2 +
  3 +@iftex
  4 +@settitle QEMU Internals
  5 +@titlepage
  6 +@sp 7
  7 +@center @titlefont{QEMU Internals}
  8 +@sp 3
  9 +@end titlepage
  10 +@end iftex
  11 +
  12 +@chapter Introduction
  13 +
  14 +@section Features
  15 +
  16 +QEMU is a FAST! processor emulator using a portable dynamic
  17 +translator.
  18 +
  19 +QEMU has two operating modes:
  20 +
  21 +@itemize @minus
  22 +
  23 +@item
  24 +Full system emulation. In this mode, QEMU emulates a full system
  25 +(usually a PC), including a processor and various peripherials. It can
  26 +be used to launch an different Operating System without rebooting the
  27 +PC or to debug system code.
  28 +
  29 +@item
  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.
  34 +
  35 +@end itemize
  36 +
  37 +As QEMU requires no host kernel driver to run, it is very safe and
  38 +easy to use.
  39 +
  40 +QEMU generic features:
  41 +
  42 +@itemize
  43 +
  44 +@item User space only or full system emulation.
  45 +
  46 +@item Using dynamic translation to native code for reasonnable speed.
  47 +
  48 +@item Working on x86 and PowerPC hosts. Being tested on ARM, Sparc32, Alpha and S390.
  49 +
  50 +@item Self-modifying code support.
  51 +
  52 +@item Precise exceptions support.
  53 +
  54 +@item The virtual CPU is a library (@code{libqemu}) which can be used
  55 +in other projects.
  56 +
  57 +@end itemize
  58 +
  59 +QEMU user mode emulation features:
  60 +@itemize
  61 +@item Generic Linux system call converter, including most ioctls.
  62 +
  63 +@item clone() emulation using native CPU clone() to use Linux scheduler for threads.
  64 +
  65 +@item Accurate signal handling by remapping host signals to target signals.
  66 +@end itemize
  67 +@end itemize
  68 +
  69 +QEMU full system emulation features:
  70 +@itemize
  71 +@item QEMU can either use a full software MMU for maximum portability or use the host system call mmap() to simulate the target MMU.
  72 +@end itemize
  73 +
  74 +@section x86 emulation
  75 +
  76 +QEMU x86 target features:
  77 +
  78 +@itemize
  79 +
  80 +@item The virtual x86 CPU supports 16 bit and 32 bit addressing with segmentation.
  81 +LDT/GDT and IDT are emulated. VM86 mode is also supported to run DOSEMU.
  82 +
  83 +@item Support of host page sizes bigger than 4KB in user mode emulation.
  84 +
  85 +@item QEMU can emulate itself on x86.
  86 +
  87 +@item An extensive Linux x86 CPU test program is included @file{tests/test-i386}.
  88 +It can be used to test other x86 virtual CPUs.
  89 +
  90 +@end itemize
  91 +
  92 +Current QEMU limitations:
  93 +
  94 +@itemize
  95 +
  96 +@item No SSE/MMX support (yet).
  97 +
  98 +@item No x86-64 support.
  99 +
  100 +@item IPC syscalls are missing.
  101 +
  102 +@item The x86 segment limits and access rights are not tested at every
  103 +memory access (yet). Hopefully, very few OSes seem to rely on that for
  104 +normal use.
  105 +
  106 +@item On non x86 host CPUs, @code{double}s are used instead of the non standard
  107 +10 byte @code{long double}s of x86 for floating point emulation to get
  108 +maximum performances.
  109 +
  110 +@end itemize
  111 +
  112 +@section ARM emulation
  113 +
  114 +@itemize
  115 +
  116 +@item Full ARM 7 user emulation.
  117 +
  118 +@item NWFPE FPU support included in user Linux emulation.
  119 +
  120 +@item Can run most ARM Linux binaries.
  121 +
  122 +@end itemize
  123 +
  124 +@section PowerPC emulation
  125 +
  126 +@itemize
  127 +
  128 +@item Full PowerPC 32 bit emulation, including priviledged instructions,
  129 +FPU and MMU.
  130 +
  131 +@item Can run most PowerPC Linux binaries.
  132 +
  133 +@end itemize
  134 +
  135 +@section SPARC emulation
  136 +
  137 +@itemize
  138 +
  139 +@item SPARC V8 user support, except FPU instructions.
  140 +
  141 +@item Can run some SPARC Linux binaries.
  142 +
  143 +@end itemize
  144 +
  145 +@chapter QEMU Internals
  146 +
  147 +@section QEMU compared to other emulators
  148 +
  149 +Like bochs [3], QEMU emulates an x86 CPU. But QEMU is much faster than
  150 +bochs as it uses dynamic compilation. Bochs is closely tied to x86 PC
  151 +emulation while QEMU can emulate several processors.
  152 +
  153 +Like Valgrind [2], QEMU does user space emulation and dynamic
  154 +translation. Valgrind is mainly a memory debugger while QEMU has no
  155 +support for it (QEMU could be used to detect out of bound memory
  156 +accesses as Valgrind, but it has no support to track uninitialised data
  157 +as Valgrind does). The Valgrind dynamic translator generates better code
  158 +than QEMU (in particular it does register allocation) but it is closely
  159 +tied to an x86 host and target and has no support for precise exceptions
  160 +and system emulation.
  161 +
  162 +EM86 [4] is the closest project to user space QEMU (and QEMU still uses
  163 +some of its code, in particular the ELF file loader). EM86 was limited
  164 +to an alpha host and used a proprietary and slow interpreter (the
  165 +interpreter part of the FX!32 Digital Win32 code translator [5]).
  166 +
  167 +TWIN [6] is a Windows API emulator like Wine. It is less accurate than
  168 +Wine but includes a protected mode x86 interpreter to launch x86 Windows
  169 +executables. Such an approach as greater potential because most of the
  170 +Windows API is executed natively but it is far more difficult to develop
  171 +because all the data structures and function parameters exchanged
  172 +between the API and the x86 code must be converted.
  173 +
  174 +User mode Linux [7] was the only solution before QEMU to launch a
  175 +Linux kernel as a process while not needing any host kernel
  176 +patches. However, user mode Linux requires heavy kernel patches while
  177 +QEMU accepts unpatched Linux kernels. The price to pay is that QEMU is
  178 +slower.
  179 +
  180 +The new Plex86 [8] PC virtualizer is done in the same spirit as the
  181 +qemu-fast system emulator. It requires a patched Linux kernel to work
  182 +(you cannot launch the same kernel on your PC), but the patches are
  183 +really small. As it is a PC virtualizer (no emulation is done except
  184 +for some priveledged instructions), it has the potential of being
  185 +faster than QEMU. The downside is that a complicated (and potentially
  186 +unsafe) host kernel patch is needed.
  187 +
  188 +The commercial PC Virtualizers (VMWare [9], VirtualPC [10], TwoOStwo
  189 +[11]) are faster than QEMU, but they all need specific, proprietary
  190 +and potentially unsafe host drivers. Moreover, they are unable to
  191 +provide cycle exact simulation as an emulator can.
  192 +
  193 +@section Portable dynamic translation
  194 +
  195 +QEMU is a dynamic translator. When it first encounters a piece of code,
  196 +it converts it to the host instruction set. Usually dynamic translators
  197 +are very complicated and highly CPU dependent. QEMU uses some tricks
  198 +which make it relatively easily portable and simple while achieving good
  199 +performances.
  200 +
  201 +The basic idea is to split every x86 instruction into fewer simpler
  202 +instructions. Each simple instruction is implemented by a piece of C
  203 +code (see @file{target-i386/op.c}). Then a compile time tool
  204 +(@file{dyngen}) takes the corresponding object file (@file{op.o})
  205 +to generate a dynamic code generator which concatenates the simple
  206 +instructions to build a function (see @file{op.h:dyngen_code()}).
  207 +
  208 +In essence, the process is similar to [1], but more work is done at
  209 +compile time.
  210 +
  211 +A key idea to get optimal performances is that constant parameters can
  212 +be passed to the simple operations. For that purpose, dummy ELF
  213 +relocations are generated with gcc for each constant parameter. Then,
  214 +the tool (@file{dyngen}) can locate the relocations and generate the
  215 +appriopriate C code to resolve them when building the dynamic code.
  216 +
  217 +That way, QEMU is no more difficult to port than a dynamic linker.
  218 +
  219 +To go even faster, GCC static register variables are used to keep the
  220 +state of the virtual CPU.
  221 +
  222 +@section Register allocation
  223 +
  224 +Since QEMU uses fixed simple instructions, no efficient register
  225 +allocation can be done. However, because RISC CPUs have a lot of
  226 +register, most of the virtual CPU state can be put in registers without
  227 +doing complicated register allocation.
  228 +
  229 +@section Condition code optimisations
  230 +
  231 +Good CPU condition codes emulation (@code{EFLAGS} register on x86) is a
  232 +critical point to get good performances. QEMU uses lazy condition code
  233 +evaluation: instead of computing the condition codes after each x86
  234 +instruction, it just stores one operand (called @code{CC_SRC}), the
  235 +result (called @code{CC_DST}) and the type of operation (called
  236 +@code{CC_OP}).
  237 +
  238 +@code{CC_OP} is almost never explicitely set in the generated code
  239 +because it is known at translation time.
  240 +
  241 +In order to increase performances, a backward pass is performed on the
  242 +generated simple instructions (see
  243 +@code{target-i386/translate.c:optimize_flags()}). When it can be proved that
  244 +the condition codes are not needed by the next instructions, no
  245 +condition codes are computed at all.
  246 +
  247 +@section CPU state optimisations
  248 +
  249 +The x86 CPU has many internal states which change the way it evaluates
  250 +instructions. In order to achieve a good speed, the translation phase
  251 +considers that some state information of the virtual x86 CPU cannot
  252 +change in it. For example, if the SS, DS and ES segments have a zero
  253 +base, then the translator does not even generate an addition for the
  254 +segment base.
  255 +
  256 +[The FPU stack pointer register is not handled that way yet].
  257 +
  258 +@section Translation cache
  259 +
  260 +A 2MByte cache holds the most recently used translations. For
  261 +simplicity, it is completely flushed when it is full. A translation unit
  262 +contains just a single basic block (a block of x86 instructions
  263 +terminated by a jump or by a virtual CPU state change which the
  264 +translator cannot deduce statically).
  265 +
  266 +@section Direct block chaining
  267 +
  268 +After each translated basic block is executed, QEMU uses the simulated
  269 +Program Counter (PC) and other cpu state informations (such as the CS
  270 +segment base value) to find the next basic block.
  271 +
  272 +In order to accelerate the most common cases where the new simulated PC
  273 +is known, QEMU can patch a basic block so that it jumps directly to the
  274 +next one.
  275 +
  276 +The most portable code uses an indirect jump. An indirect jump makes
  277 +it easier to make the jump target modification atomic. On some host
  278 +architectures (such as x86 or PowerPC), the @code{JUMP} opcode is
  279 +directly patched so that the block chaining has no overhead.
  280 +
  281 +@section Self-modifying code and translated code invalidation
  282 +
  283 +Self-modifying code is a special challenge in x86 emulation because no
  284 +instruction cache invalidation is signaled by the application when code
  285 +is modified.
  286 +
  287 +When translated code is generated for a basic block, the corresponding
  288 +host page is write protected if it is not already read-only (with the
  289 +system call @code{mprotect()}). Then, if a write access is done to the
  290 +page, Linux raises a SEGV signal. QEMU then invalidates all the
  291 +translated code in the page and enables write accesses to the page.
  292 +
  293 +Correct translated code invalidation is done efficiently by maintaining
  294 +a linked list of every translated block contained in a given page. Other
  295 +linked lists are also maintained to undo direct block chaining.
  296 +
  297 +Although the overhead of doing @code{mprotect()} calls is important,
  298 +most MSDOS programs can be emulated at reasonnable speed with QEMU and
  299 +DOSEMU.
  300 +
  301 +Note that QEMU also invalidates pages of translated code when it detects
  302 +that memory mappings are modified with @code{mmap()} or @code{munmap()}.
  303 +
  304 +When using a software MMU, the code invalidation is more efficient: if
  305 +a given code page is invalidated too often because of write accesses,
  306 +then a bitmap representing all the code inside the page is
  307 +built. Every store into that page checks the bitmap to see if the code
  308 +really needs to be invalidated. It avoids invalidating the code when
  309 +only data is modified in the page.
  310 +
  311 +@section Exception support
  312 +
  313 +longjmp() is used when an exception such as division by zero is
  314 +encountered.
  315 +
  316 +The host SIGSEGV and SIGBUS signal handlers are used to get invalid
  317 +memory accesses. The exact CPU state can be retrieved because all the
  318 +x86 registers are stored in fixed host registers. The simulated program
  319 +counter is found by retranslating the corresponding basic block and by
  320 +looking where the host program counter was at the exception point.
  321 +
  322 +The virtual CPU cannot retrieve the exact @code{EFLAGS} register because
  323 +in some cases it is not computed because of condition code
  324 +optimisations. It is not a big concern because the emulated code can
  325 +still be restarted in any cases.
  326 +
  327 +@section MMU emulation
  328 +
  329 +For system emulation, QEMU uses the mmap() system call to emulate the
  330 +target CPU MMU. It works as long the emulated OS does not use an area
  331 +reserved by the host OS (such as the area above 0xc0000000 on x86
  332 +Linux).
  333 +
  334 +In order to be able to launch any OS, QEMU also supports a soft
  335 +MMU. In that mode, the MMU virtual to physical address translation is
  336 +done at every memory access. QEMU uses an address translation cache to
  337 +speed up the translation.
  338 +
  339 +In order to avoid flushing the translated code each time the MMU
  340 +mappings change, QEMU uses a physically indexed translation cache. It
  341 +means that each basic block is indexed with its physical address.
  342 +
  343 +When MMU mappings change, only the chaining of the basic blocks is
  344 +reset (i.e. a basic block can no longer jump directly to another one).
  345 +
  346 +@section Hardware interrupts
  347 +
  348 +In order to be faster, QEMU does not check at every basic block if an
  349 +hardware interrupt is pending. Instead, the user must asynchrously
  350 +call a specific function to tell that an interrupt is pending. This
  351 +function resets the chaining of the currently executing basic
  352 +block. It ensures that the execution will return soon in the main loop
  353 +of the CPU emulator. Then the main loop can test if the interrupt is
  354 +pending and handle it.
  355 +
  356 +@section User emulation specific details
  357 +
  358 +@subsection Linux system call translation
  359 +
  360 +QEMU includes a generic system call translator for Linux. It means that
  361 +the parameters of the system calls can be converted to fix the
  362 +endianness and 32/64 bit issues. The IOCTLs are converted with a generic
  363 +type description system (see @file{ioctls.h} and @file{thunk.c}).
  364 +
  365 +QEMU supports host CPUs which have pages bigger than 4KB. It records all
  366 +the mappings the process does and try to emulated the @code{mmap()}
  367 +system calls in cases where the host @code{mmap()} call would fail
  368 +because of bad page alignment.
  369 +
  370 +@subsection Linux signals
  371 +
  372 +Normal and real-time signals are queued along with their information
  373 +(@code{siginfo_t}) as it is done in the Linux kernel. Then an interrupt
  374 +request is done to the virtual CPU. When it is interrupted, one queued
  375 +signal is handled by generating a stack frame in the virtual CPU as the
  376 +Linux kernel does. The @code{sigreturn()} system call is emulated to return
  377 +from the virtual signal handler.
  378 +
  379 +Some signals (such as SIGALRM) directly come from the host. Other
  380 +signals are synthetized from the virtual CPU exceptions such as SIGFPE
  381 +when a division by zero is done (see @code{main.c:cpu_loop()}).
  382 +
  383 +The blocked signal mask is still handled by the host Linux kernel so
  384 +that most signal system calls can be redirected directly to the host
  385 +Linux kernel. Only the @code{sigaction()} and @code{sigreturn()} system
  386 +calls need to be fully emulated (see @file{signal.c}).
  387 +
  388 +@subsection clone() system call and threads
  389 +
  390 +The Linux clone() system call is usually used to create a thread. QEMU
  391 +uses the host clone() system call so that real host threads are created
  392 +for each emulated thread. One virtual CPU instance is created for each
  393 +thread.
  394 +
  395 +The virtual x86 CPU atomic operations are emulated with a global lock so
  396 +that their semantic is preserved.
  397 +
  398 +Note that currently there are still some locking issues in QEMU. In
  399 +particular, the translated cache flush is not protected yet against
  400 +reentrancy.
  401 +
  402 +@subsection Self-virtualization
  403 +
  404 +QEMU was conceived so that ultimately it can emulate itself. Although
  405 +it is not very useful, it is an important test to show the power of the
  406 +emulator.
  407 +
  408 +Achieving self-virtualization is not easy because there may be address
  409 +space conflicts. QEMU solves this problem by being an executable ELF
  410 +shared object as the ld-linux.so ELF interpreter. That way, it can be
  411 +relocated at load time.
  412 +
  413 +@section Bibliography
  414 +
  415 +@table @asis
  416 +
  417 +@item [1]
  418 +@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing
  419 +direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio
  420 +Riccardi.
  421 +
  422 +@item [2]
  423 +@url{http://developer.kde.org/~sewardj/}, Valgrind, an open-source
  424 +memory debugger for x86-GNU/Linux, by Julian Seward.
  425 +
  426 +@item [3]
  427 +@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,
  428 +by Kevin Lawton et al.
  429 +
  430 +@item [4]
  431 +@url{http://www.cs.rose-hulman.edu/~donaldlf/em86/index.html}, the EM86
  432 +x86 emulator on Alpha-Linux.
  433 +
  434 +@item [5]
  435 +@url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/full_papers/chernoff/chernoff.pdf},
  436 +DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton
  437 +Chernoff and Ray Hookway.
  438 +
  439 +@item [6]
  440 +@url{http://www.willows.com/}, Windows API library emulation from
  441 +Willows Software.
  442 +
  443 +@item [7]
  444 +@url{http://user-mode-linux.sourceforge.net/},
  445 +The User-mode Linux Kernel.
  446 +
  447 +@item [8]
  448 +@url{http://www.plex86.org/},
  449 +The new Plex86 project.
  450 +
  451 +@item [9]
  452 +@url{http://www.vmware.com/},
  453 +The VMWare PC virtualizer.
  454 +
  455 +@item [10]
  456 +@url{http://www.microsoft.com/windowsxp/virtualpc/},
  457 +The VirtualPC PC virtualizer.
  458 +
  459 +@item [11]
  460 +@url{http://www.twoostwo.org/},
  461 +The TwoOStwo PC virtualizer.
  462 +
  463 +@end table
  464 +
  465 +@chapter Regression Tests
  466 +
  467 +In the directory @file{tests/}, various interesting testing programs
  468 +are available. There are used for regression testing.
  469 +
  470 +@section @file{test-i386}
  471 +
  472 +This program executes most of the 16 bit and 32 bit x86 instructions and
  473 +generates a text output. It can be compared with the output obtained with
  474 +a real CPU or another emulator. The target @code{make test} runs this
  475 +program and a @code{diff} on the generated output.
  476 +
  477 +The Linux system call @code{modify_ldt()} is used to create x86 selectors
  478 +to test some 16 bit addressing and 32 bit with segmentation cases.
  479 +
  480 +The Linux system call @code{vm86()} is used to test vm86 emulation.
  481 +
  482 +Various exceptions are raised to test most of the x86 user space
  483 +exception reporting.
  484 +
  485 +@section @file{linux-test}
  486 +
  487 +This program tests various Linux system calls. It is used to verify
  488 +that the system call parameters are correctly converted between target
  489 +and host CPUs.
  490 +
  491 +@section @file{hello-i386}
  492 +
  493 +Very simple statically linked x86 program, just to test QEMU during a
  494 +port to a new host CPU.
  495 +
  496 +@section @file{hello-arm}
  497 +
  498 +Very simple statically linked ARM program, just to test QEMU during a
  499 +port to a new host CPU.
  500 +
  501 +@section @file{sha1}
  502 +
  503 +It is a simple benchmark. Care must be taken to interpret the results
  504 +because it mostly tests the ability of the virtual CPU to optimize the
  505 +@code{rol} x86 instruction and the condition code computations.
  506 +