Kconfig (6068B)
1# SPDX-License-Identifier: GPL-2.0 2 3menu "UML-specific options" 4 5config UML 6 bool 7 default y 8 select ARCH_EPHEMERAL_INODES 9 select ARCH_HAS_GCOV_PROFILE_ALL 10 select ARCH_HAS_KCOV 11 select ARCH_HAS_STRNCPY_FROM_USER 12 select ARCH_HAS_STRNLEN_USER 13 select ARCH_NO_PREEMPT 14 select HAVE_ARCH_AUDITSYSCALL 15 select HAVE_ARCH_SECCOMP_FILTER 16 select HAVE_ASM_MODVERSIONS 17 select HAVE_UID16 18 select HAVE_DEBUG_KMEMLEAK 19 select HAVE_DEBUG_BUGVERBOSE 20 select NO_DMA if !UML_DMA_EMULATION 21 select OF_EARLY_FLATTREE if OF 22 select GENERIC_IRQ_SHOW 23 select GENERIC_CPU_DEVICES 24 select HAVE_GCC_PLUGINS 25 select TRACE_IRQFLAGS_SUPPORT 26 select TTY # Needed for line.c 27 select HAVE_ARCH_VMAP_STACK 28 29config MMU 30 bool 31 default y 32 33config UML_DMA_EMULATION 34 bool 35 36config NO_IOMEM 37 bool "disable IOMEM" if EXPERT 38 depends on !INDIRECT_IOMEM 39 default y 40 41config UML_IOMEM_EMULATION 42 bool 43 select INDIRECT_IOMEM 44 select GENERIC_PCI_IOMAP 45 select GENERIC_IOMAP 46 select NO_GENERIC_PCI_IOPORT_MAP 47 48config NO_IOPORT_MAP 49 def_bool y 50 51config ISA 52 bool 53 54config SBUS 55 bool 56 57config LOCKDEP_SUPPORT 58 bool 59 default y 60 61config STACKTRACE_SUPPORT 62 bool 63 default y 64 select STACKTRACE 65 66config GENERIC_CALIBRATE_DELAY 67 bool 68 default y 69 70config HZ 71 int 72 default 100 73 74config NR_CPUS 75 int 76 range 1 1 77 default 1 78 79config ARCH_HAS_CACHE_LINE_SIZE 80 def_bool y 81 82source "arch/$(HEADER_ARCH)/um/Kconfig" 83 84config MAY_HAVE_RUNTIME_DEPS 85 bool 86 87config STATIC_LINK 88 bool "Force a static link" 89 depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || !MAY_HAVE_RUNTIME_DEPS 90 help 91 This option gives you the ability to force a static link of UML. 92 Normally, UML is linked as a shared binary. This is inconvenient for 93 use in a chroot jail. So, if you intend to run UML inside a chroot, 94 you probably want to say Y here. 95 Additionally, this option enables using higher memory spaces (up to 96 2.75G) for UML. 97 98 NOTE: This option is incompatible with some networking features which 99 depend on features that require being dynamically loaded (like NSS). 100 101config LD_SCRIPT_STATIC 102 bool 103 default y 104 depends on STATIC_LINK 105 106config LD_SCRIPT_DYN 107 bool 108 default y 109 depends on !LD_SCRIPT_STATIC 110 111config LD_SCRIPT_DYN_RPATH 112 bool "set rpath in the binary" if EXPERT 113 default y 114 depends on LD_SCRIPT_DYN 115 help 116 Add /lib (and /lib64 for 64-bit) to the linux binary's rpath 117 explicitly. 118 119 You may need to turn this off if compiling for nix systems 120 that have their libraries in random /nix directories and 121 might otherwise unexpected use libraries from /lib or /lib64 122 instead of the desired ones. 123 124config HOSTFS 125 tristate "Host filesystem" 126 help 127 While the User-Mode Linux port uses its own root file system for 128 booting and normal file access, this module lets the UML user 129 access files stored on the host. It does not require any 130 network connection between the Host and UML. An example use of 131 this might be: 132 133 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare 134 135 where /tmp/fromhost is an empty directory inside UML and 136 /tmp/umlshare is a directory on the host with files the UML user 137 wishes to access. 138 139 For more information, see 140 <http://user-mode-linux.sourceforge.net/hostfs.html>. 141 142 If you'd like to be able to work with files stored on the host, 143 say Y or M here; otherwise say N. 144 145config MCONSOLE 146 bool "Management console" 147 depends on PROC_FS 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/admin-guide/sysrq.rst>. Don't say Y 180 unless you really know what this hack does. 181 182config KERNEL_STACK_ORDER 183 int "Kernel stack size order" 184 default 2 if 64BIT 185 range 2 10 if 64BIT 186 default 1 if !64BIT 187 help 188 This option determines the size of UML kernel stacks. They will 189 be 1 << order pages. The default is OK unless you're running Valgrind 190 on UML, in which case, set this to 3. 191 It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on 192 older (pre-2017) CPUs. It is not recommended on newer CPUs due to the 193 increase in the size of the state which needs to be saved when handling 194 signals. 195 196config MMAPPER 197 tristate "iomem emulation driver" 198 help 199 This driver allows a host file to be used as emulated IO memory inside 200 UML. 201 202config PGTABLE_LEVELS 203 int 204 default 3 if 3_LEVEL_PGTABLES 205 default 2 206 207config UML_TIME_TRAVEL_SUPPORT 208 bool 209 prompt "Support time-travel mode (e.g. for test execution)" 210 # inf-cpu mode is incompatible with the benchmarking 211 depends on !RAID6_PQ_BENCHMARK 212 depends on !SMP 213 help 214 Enable this option to support time travel inside the UML instance. 215 216 After enabling this option, two modes are accessible at runtime 217 (selected by the kernel command line), see the kernel's command- 218 line help for more details. 219 220 It is safe to say Y, but you probably don't need this. 221 222endmenu 223 224source "arch/um/drivers/Kconfig" 225 226config ARCH_SUSPEND_POSSIBLE 227 def_bool y 228 229source "kernel/power/Kconfig"