1# UML uses the generic IRQ sugsystem 2config GENERIC_HARDIRQS 3 bool 4 default y 5 6config UML 7 bool 8 default y 9 10# XXX: does UM have a mmu/swap? 11config MMU 12 bool 13 default y 14 15mainmenu "Linux/Usermode Kernel Configuration" 16 17config ISA 18 bool 19 20config SBUS 21 bool 22 23config PCI 24 bool 25 26config UID16 27 bool 28 default y 29 30config RWSEM_GENERIC_SPINLOCK 31 bool 32 default y 33 34config GENERIC_CALIBRATE_DELAY 35 bool 36 default y 37 38# Used in kernel/irq/manage.c and include/linux/irq.h 39config IRQ_RELEASE_METHOD 40 bool 41 default y 42 43menu "UML-specific options" 44 45config MODE_TT 46 bool "Tracing thread support" 47 default y 48 help 49 This option controls whether tracing thread support is compiled 50 into UML. Normally, this should be set to Y. If you intend to 51 use only skas mode (and the host has the skas patch applied to it), 52 then it is OK to say N here. 53 54config STATIC_LINK 55 bool "Force a static link" 56 default n 57 depends on !MODE_TT 58 help 59 If CONFIG_MODE_TT is disabled, then this option gives you the ability 60 to force a static link of UML. Normally, if only skas mode is built 61 in to UML, it will be linked as a shared binary. This is inconvenient 62 for use in a chroot jail. So, if you intend to run UML inside a 63 chroot, and you disable CONFIG_MODE_TT, you probably want to say Y 64 here. 65 66config MODE_SKAS 67 bool "Separate Kernel Address Space support" 68 default y 69 help 70 This option controls whether skas (separate kernel address space) 71 support is compiled in. If you have applied the skas patch to the 72 host, then you certainly want to say Y here (and consider saying N 73 to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this 74 option will shrink the UML binary slightly. 75 76source "arch/um/Kconfig_arch" 77 78config LD_SCRIPT_STATIC 79 bool 80 default y 81 depends on MODE_TT || STATIC_LINK 82 83config LD_SCRIPT_DYN 84 bool 85 default y 86 depends on !LD_SCRIPT_STATIC 87 88config NET 89 bool "Networking support" 90 help 91 Unless you really know what you are doing, you should say Y here. 92 The reason is that some programs need kernel networking support even 93 when running on a stand-alone machine that isn't connected to any 94 other computer. If you are upgrading from an older kernel, you 95 should consider updating your networking tools too because changes 96 in the kernel and the tools often go hand in hand. The tools are 97 contained in the package net-tools, the location and version number 98 of which are given in <file:Documentation/Changes>. 99 100 For a general introduction to Linux networking, it is highly 101 recommended to read the NET-HOWTO, available from 102 <http://www.tldp.org/docs.html#howto>. 103 104 105source "fs/Kconfig.binfmt" 106 107config HOSTFS 108 tristate "Host filesystem" 109 help 110 While the User-Mode Linux port uses its own root file system for 111 booting and normal file access, this module lets the UML user 112 access files stored on the host. It does not require any 113 network connection between the Host and UML. An example use of 114 this might be: 115 116 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare 117 118 where /tmp/fromhost is an empty directory inside UML and 119 /tmp/umlshare is a directory on the host with files the UML user 120 wishes to access. 121 122 For more information, see 123 <http://user-mode-linux.sourceforge.net/hostfs.html>. 124 125 If you'd like to be able to work with files stored on the host, 126 say Y or M here; otherwise say N. 127 128config HPPFS 129 tristate "HoneyPot ProcFS (EXPERIMENTAL)" 130 depends on BROKEN 131 help 132 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc 133 entries to be overridden, removed, or fabricated from the host. 134 Its purpose is to allow a UML to appear to be a physical machine 135 by removing or changing anything in /proc which gives away the 136 identity of a UML. 137 138 See <http://user-mode-linux.sf.net/hppfs.html> for more information. 139 140 You only need this if you are setting up a UML honeypot. Otherwise, 141 it is safe to say 'N' here. 142 143 If you are actively using it, please ask for it to be fixed. In this 144 moment, it does not work on 2.6 (it works somehow on 2.4). 145 146config MCONSOLE 147 bool "Management console" 148 default y 149 help 150 The user mode linux management console is a low-level interface to 151 the kernel, somewhat like the i386 SysRq interface. Since there is 152 a full-blown operating system running under every user mode linux 153 instance, there is much greater flexibility possible than with the 154 SysRq mechanism. 155 156 If you answer 'Y' to this option, to use this feature, you need the 157 mconsole client (called uml_mconsole) which is present in CVS in 158 2.4.5-9um and later (path /tools/mconsole), and is also in the 159 distribution RPM package in 2.4.6 and later. 160 161 It is safe to say 'Y' here. 162 163config MAGIC_SYSRQ 164 bool "Magic SysRq key" 165 depends on MCONSOLE 166 ---help--- 167 If you say Y here, you will have some control over the system even 168 if the system crashes for example during kernel debugging (e.g., you 169 will be able to flush the buffer cache to disk, reboot the system 170 immediately or dump some status information). A key for each of the 171 possible requests is provided. 172 173 This is the feature normally accomplished by pressing a key 174 while holding SysRq (Alt+PrintScreen). 175 176 On UML, this is accomplished by sending a "sysrq" command with 177 mconsole, followed by the letter for the requested command. 178 179 The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y 180 unless you really know what this hack does. 181 182config HOST_2G_2G 183 bool "2G/2G host address space split" 184 default n 185 help 186 This is needed when the host on which you run has a 2G/2G memory 187 split, instead of the customary 3G/1G. 188 189 Note that to enable such a host 190 configuration, which makes sense only in some cases, you need special 191 host patches. 192 193 So, if you do not know what to do here, say 'N'. 194 195config SMP 196 bool "Symmetric multi-processing support (EXPERIMENTAL)" 197 default n 198 depends on MODE_TT && EXPERIMENTAL 199 help 200 This option enables UML SMP support. 201 It is NOT related to having a real SMP box. Not directly, at least. 202 203 UML implements virtual SMP by allowing as many processes to run 204 simultaneously on the host as there are virtual processors configured. 205 206 Obviously, if the host is a uniprocessor, those processes will 207 timeshare, but, inside UML, will appear to be running simultaneously. 208 If the host is a multiprocessor, then UML processes may run 209 simultaneously, depending on the host scheduler. 210 211 This, however, is supported only in TT mode. So, if you use the SKAS 212 patch on your host, switching to TT mode and enabling SMP usually gives 213 you worse performances. 214 Also, since the support for SMP has been under-developed, there could 215 be some bugs being exposed by enabling SMP. 216 217 If you don't know what to do, say N. 218 219config NR_CPUS 220 int "Maximum number of CPUs (2-32)" 221 range 2 32 222 depends on SMP 223 default "32" 224 225config NEST_LEVEL 226 int "Nesting level" 227 default "0" 228 help 229 This is set to the number of layers of UMLs that this UML will be run 230 in. Normally, this is zero, meaning that it will run directly on the 231 host. Setting it to one will build a UML that can run inside a UML 232 that is running on the host. Generally, if you intend this UML to run 233 inside another UML, set CONFIG_NEST_LEVEL to one more than the host 234 UML. 235 236 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to 237 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL 238 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS. 239 Only change this if you are running nested UMLs. 240 241config KERNEL_HALF_GIGS 242 int "Kernel address space size (in .5G units)" 243 default "1" 244 help 245 This determines the amount of address space that UML will allocate for 246 its own, measured in half Gigabyte units. The default is 1. 247 Change this only if you need to boot UML with an unusually large amount 248 of physical memory. 249 250config HIGHMEM 251 bool "Highmem support" 252 depends on !64BIT 253 254config KERNEL_STACK_ORDER 255 int "Kernel stack size order" 256 default 2 257 help 258 This option determines the size of UML kernel stacks. They will 259 be 1 << order pages. The default is OK unless you're running Valgrind 260 on UML, in which case, set this to 3. 261 262config UML_REAL_TIME_CLOCK 263 bool "Real-time Clock" 264 default y 265 help 266 This option makes UML time deltas match wall clock deltas. This should 267 normally be enabled. The exception would be if you are debugging with 268 UML and spend long times with UML stopped at a breakpoint. In this 269 case, when UML is restarted, it will call the timer enough times to make 270 up for the time spent at the breakpoint. This could result in a 271 noticable lag. If this is a problem, then disable this option. 272 273endmenu 274 275source "init/Kconfig" 276 277source "drivers/base/Kconfig" 278 279source "arch/um/Kconfig_char" 280 281source "drivers/block/Kconfig" 282 283config NETDEVICES 284 bool 285 default NET 286 287source "arch/um/Kconfig_net" 288 289source "net/Kconfig" 290 291source "fs/Kconfig" 292 293source "security/Kconfig" 294 295source "crypto/Kconfig" 296 297source "lib/Kconfig" 298 299menu "SCSI support" 300depends on BROKEN 301 302config SCSI 303 tristate "SCSI support" 304 305# This gives us free_dma, which scsi.c wants. 306config GENERIC_ISA_DMA 307 bool 308 depends on SCSI 309 default y 310 311source "arch/um/Kconfig_scsi" 312 313endmenu 314 315source "drivers/md/Kconfig" 316 317if BROKEN 318 source "drivers/mtd/Kconfig" 319endif 320 321#This is just to shut up some Kconfig warnings, so no prompt. 322config INPUT 323 bool 324 default n 325 326source "arch/um/Kconfig.debug" 327