1config DEFCONFIG_LIST 2 string 3 option defconfig_list 4 default "arch/$ARCH/defconfig" 5 6# UML uses the generic IRQ sugsystem 7config GENERIC_HARDIRQS 8 bool 9 default y 10 11config UML 12 bool 13 default y 14 15config MMU 16 bool 17 default y 18 19config NO_IOMEM 20 def_bool y 21 22mainmenu "Linux/Usermode Kernel Configuration" 23 24config ISA 25 bool 26 27config SBUS 28 bool 29 30config PCI 31 bool 32 33config PCMCIA 34 bool 35 36# Yet to do! 37config TRACE_IRQFLAGS_SUPPORT 38 bool 39 default n 40 41config LOCKDEP_SUPPORT 42 bool 43 default y 44 45config STACKTRACE_SUPPORT 46 bool 47 default n 48 49config GENERIC_CALIBRATE_DELAY 50 bool 51 default y 52 53config GENERIC_BUG 54 bool 55 default y 56 depends on BUG 57 58# Used in kernel/irq/manage.c and include/linux/irq.h 59config IRQ_RELEASE_METHOD 60 bool 61 default y 62 63menu "UML-specific options" 64 65config MODE_TT 66 bool "Tracing thread support (DEPRECATED)" 67 default n 68 depends on BROKEN 69 help 70 This option controls whether tracing thread support is compiled 71 into UML. This option is largely obsolete, given that skas0 provides 72 skas security and performance without needing to patch the host. 73 It is safe to say 'N' here; saying 'Y' may cause additional problems 74 with the resulting binary even if you run UML in SKAS mode, and running 75 in TT mode is strongly *NOT RECOMMENDED*. 76 77config STATIC_LINK 78 bool "Force a static link" 79 default n 80 depends on !MODE_TT 81 help 82 If CONFIG_MODE_TT is disabled, then this option gives you the ability 83 to force a static link of UML. Normally, if only skas mode is built 84 in to UML, it will be linked as a shared binary. This is inconvenient 85 for use in a chroot jail. So, if you intend to run UML inside a 86 chroot, and you disable CONFIG_MODE_TT, you probably want to say Y 87 here. 88 Additionally, this option enables using higher memory spaces (up to 89 2.75G) for UML - disabling CONFIG_MODE_TT and enabling this option leads 90 to best results for this. 91 92config KERNEL_HALF_GIGS 93 int "Kernel address space size (in .5G units)" 94 default "1" 95 depends on MODE_TT 96 help 97 This determines the amount of address space that UML will allocate for 98 its own, measured in half Gigabyte units. The default is 1. 99 Change this only if you need to boot UML with an unusually large amount 100 of physical memory. 101 102config MODE_SKAS 103 bool "Separate Kernel Address Space support" if MODE_TT 104 default y 105 help 106 This option controls whether skas (separate kernel address space) 107 support is compiled in. 108 Unless you have specific needs to use TT mode (which applies almost only 109 to developers), you should say Y here. 110 SKAS mode will make use of the SKAS3 patch if it is applied on the host 111 (and your UML will run in SKAS3 mode), but if no SKAS patch is applied 112 on the host it will run in SKAS0 mode, which is anyway faster than TT 113 mode. 114 115source "arch/um/Kconfig.arch" 116source "mm/Kconfig" 117 118config LD_SCRIPT_STATIC 119 bool 120 default y 121 depends on MODE_TT || STATIC_LINK 122 123config LD_SCRIPT_DYN 124 bool 125 default y 126 depends on !LD_SCRIPT_STATIC 127 128config NET 129 bool "Networking support" 130 help 131 Unless you really know what you are doing, you should say Y here. 132 The reason is that some programs need kernel networking support even 133 when running on a stand-alone machine that isn't connected to any 134 other computer. If you are upgrading from an older kernel, you 135 should consider updating your networking tools too because changes 136 in the kernel and the tools often go hand in hand. The tools are 137 contained in the package net-tools, the location and version number 138 of which are given in <file:Documentation/Changes>. 139 140 For a general introduction to Linux networking, it is highly 141 recommended to read the NET-HOWTO, available from 142 <http://www.tldp.org/docs.html#howto>. 143 144 145source "fs/Kconfig.binfmt" 146 147config HOSTFS 148 tristate "Host filesystem" 149 help 150 While the User-Mode Linux port uses its own root file system for 151 booting and normal file access, this module lets the UML user 152 access files stored on the host. It does not require any 153 network connection between the Host and UML. An example use of 154 this might be: 155 156 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare 157 158 where /tmp/fromhost is an empty directory inside UML and 159 /tmp/umlshare is a directory on the host with files the UML user 160 wishes to access. 161 162 For more information, see 163 <http://user-mode-linux.sourceforge.net/hostfs.html>. 164 165 If you'd like to be able to work with files stored on the host, 166 say Y or M here; otherwise say N. 167 168config HPPFS 169 tristate "HoneyPot ProcFS (EXPERIMENTAL)" 170 depends on EXPERIMENTAL 171 help 172 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc 173 entries to be overridden, removed, or fabricated from the host. 174 Its purpose is to allow a UML to appear to be a physical machine 175 by removing or changing anything in /proc which gives away the 176 identity of a UML. 177 178 See <http://user-mode-linux.sf.net/hppfs.html> for more information. 179 180 You only need this if you are setting up a UML honeypot. Otherwise, 181 it is safe to say 'N' here. 182 183config MCONSOLE 184 bool "Management console" 185 default y 186 help 187 The user mode linux management console is a low-level interface to 188 the kernel, somewhat like the i386 SysRq interface. Since there is 189 a full-blown operating system running under every user mode linux 190 instance, there is much greater flexibility possible than with the 191 SysRq mechanism. 192 193 If you answer 'Y' to this option, to use this feature, you need the 194 mconsole client (called uml_mconsole) which is present in CVS in 195 2.4.5-9um and later (path /tools/mconsole), and is also in the 196 distribution RPM package in 2.4.6 and later. 197 198 It is safe to say 'Y' here. 199 200config MAGIC_SYSRQ 201 bool "Magic SysRq key" 202 depends on MCONSOLE 203 ---help--- 204 If you say Y here, you will have some control over the system even 205 if the system crashes for example during kernel debugging (e.g., you 206 will be able to flush the buffer cache to disk, reboot the system 207 immediately or dump some status information). A key for each of the 208 possible requests is provided. 209 210 This is the feature normally accomplished by pressing a key 211 while holding SysRq (Alt+PrintScreen). 212 213 On UML, this is accomplished by sending a "sysrq" command with 214 mconsole, followed by the letter for the requested command. 215 216 The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y 217 unless you really know what this hack does. 218 219config SMP 220 bool "Symmetric multi-processing support (EXPERIMENTAL)" 221 default n 222 #SMP_BROKEN is for x86_64. 223 depends on MODE_TT && EXPERIMENTAL && (!SMP_BROKEN || (BROKEN && SMP_BROKEN)) 224 help 225 This option enables UML SMP support. 226 It is NOT related to having a real SMP box. Not directly, at least. 227 228 UML implements virtual SMP by allowing as many processes to run 229 simultaneously on the host as there are virtual processors configured. 230 231 Obviously, if the host is a uniprocessor, those processes will 232 timeshare, but, inside UML, will appear to be running simultaneously. 233 If the host is a multiprocessor, then UML processes may run 234 simultaneously, depending on the host scheduler. 235 236 This, however, is supported only in TT mode. So, if you use the SKAS 237 patch on your host, switching to TT mode and enabling SMP usually gives 238 you worse performances. 239 Also, since the support for SMP has been under-developed, there could 240 be some bugs being exposed by enabling SMP. 241 242 If you don't know what to do, say N. 243 244config NR_CPUS 245 int "Maximum number of CPUs (2-32)" 246 range 2 32 247 depends on SMP 248 default "32" 249 250config NEST_LEVEL 251 int "Nesting level" 252 default "0" 253 help 254 This is set to the number of layers of UMLs that this UML will be run 255 in. Normally, this is zero, meaning that it will run directly on the 256 host. Setting it to one will build a UML that can run inside a UML 257 that is running on the host. Generally, if you intend this UML to run 258 inside another UML, set CONFIG_NEST_LEVEL to one more than the host 259 UML. 260 261 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to 262 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL 263 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS. 264 Only change this if you are running nested UMLs. 265 266config HIGHMEM 267 bool "Highmem support (EXPERIMENTAL)" 268 depends on !64BIT && EXPERIMENTAL 269 default n 270 help 271 This was used to allow UML to run with big amounts of memory. 272 Currently it is unstable, so if unsure say N. 273 274 To use big amounts of memory, it is recommended to disable TT mode (i.e. 275 CONFIG_MODE_TT) and enable static linking (i.e. CONFIG_STATIC_LINK) - 276 this should allow the guest to use up to 2.75G of memory. 277 278config KERNEL_STACK_ORDER 279 int "Kernel stack size order" 280 default 1 if 64BIT 281 range 1 10 if 64BIT 282 default 0 if !64BIT 283 help 284 This option determines the size of UML kernel stacks. They will 285 be 1 << order pages. The default is OK unless you're running Valgrind 286 on UML, in which case, set this to 3. 287 288config UML_REAL_TIME_CLOCK 289 bool "Real-time Clock" 290 default y 291 help 292 This option makes UML time deltas match wall clock deltas. This should 293 normally be enabled. The exception would be if you are debugging with 294 UML and spend long times with UML stopped at a breakpoint. In this 295 case, when UML is restarted, it will call the timer enough times to make 296 up for the time spent at the breakpoint. This could result in a 297 noticeable lag. If this is a problem, then disable this option. 298 299endmenu 300 301source "init/Kconfig" 302 303source "drivers/block/Kconfig" 304 305source "arch/um/Kconfig.char" 306 307source "drivers/base/Kconfig" 308 309source "net/Kconfig" 310 311source "arch/um/Kconfig.net" 312 313source "drivers/net/Kconfig" 314 315source "drivers/connector/Kconfig" 316 317source "fs/Kconfig" 318 319source "security/Kconfig" 320 321source "crypto/Kconfig" 322 323source "lib/Kconfig" 324 325source "drivers/scsi/Kconfig" 326 327source "drivers/md/Kconfig" 328 329if BROKEN 330 source "drivers/mtd/Kconfig" 331endif 332 333#This is just to shut up some Kconfig warnings, so no prompt. 334config INPUT 335 bool 336 default n 337 338source "arch/um/Kconfig.debug" 339