1# For a description of the syntax of this configuration file, 2# see Documentation/kbuild/config-language.txt. 3 4mainmenu "Linux/Xtensa Kernel Configuration" 5 6config FRAME_POINTER 7 bool 8 default n 9 10config ZONE_DMA 11 bool 12 default y 13 14config XTENSA 15 bool 16 default y 17 help 18 Xtensa processors are 32-bit RISC machines designed by Tensilica 19 primarily for embedded systems. These processors are both 20 configurable and extensible. The Linux port to the Xtensa 21 architecture supports all processor configurations and extensions, 22 with reasonable minimum requirements. The Xtensa Linux project has 23 a home page at <http://xtensa.sourceforge.net/>. 24 25config RWSEM_XCHGADD_ALGORITHM 26 bool 27 default y 28 29config GENERIC_FIND_NEXT_BIT 30 bool 31 default y 32 33config GENERIC_HWEIGHT 34 bool 35 default y 36 37config GENERIC_HARDIRQS 38 bool 39 default y 40 41config ARCH_HAS_ILOG2_U32 42 bool 43 default n 44 45config ARCH_HAS_ILOG2_U64 46 bool 47 default n 48 49config NO_IOPORT 50 def_bool y 51 52source "init/Kconfig" 53 54menu "Processor type and features" 55 56choice 57 prompt "Xtensa Processor Configuration" 58 default XTENSA_VARIANT_FSF 59 60config XTENSA_VARIANT_FSF 61 bool "fsf" 62endchoice 63 64config MMU 65 bool 66 default y 67 68config XTENSA_UNALIGNED_USER 69 bool "Unaligned memory access in use space" 70 ---help--- 71 The Xtensa architecture currently does not handle unaligned 72 memory accesses in hardware but through an exception handler. 73 Per default, unaligned memory accesses are disabled in user space. 74 75 Say Y here to enable unaligned memory access in user space. 76 77config PREEMPT 78 bool "Preemptible Kernel" 79 ---help--- 80 This option reduces the latency of the kernel when reacting to 81 real-time or interactive events by allowing a low priority process to 82 be preempted even if it is in kernel mode executing a system call. 83 Unfortunately the kernel code has some race conditions if both 84 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is 85 currently disabled if you are building an SMP kernel. 86 87 Say Y here if you are building a kernel for a desktop, embedded 88 or real-time system. Say N if you are unsure. 89 90config MATH_EMULATION 91 bool "Math emulation" 92 help 93 Can we use information of configuration file? 94 95config HIGHMEM 96 bool "High memory support" 97 98endmenu 99 100menu "Platform options" 101 102choice 103 prompt "Xtensa System Type" 104 default XTENSA_PLATFORM_ISS 105 106config XTENSA_PLATFORM_ISS 107 bool "ISS" 108 help 109 ISS is an acronym for Tensilica's Instruction Set Simulator. 110 111config XTENSA_PLATFORM_XT2000 112 bool "XT2000" 113 help 114 XT2000 is the name of Tensilica's feature-rich emulation platform. 115 This hardware is capable of running a full Linux distribution. 116 117endchoice 118 119 120config XTENSA_CALIBRATE_CCOUNT 121 bool "Auto calibration of the CPU clock rate" 122 ---help--- 123 On some platforms (XT2000, for example), the CPU clock rate can 124 vary. The frequency can be determined, however, by measuring 125 against a well known, fixed frequency, such as an UART oscillator. 126 127config XTENSA_CPU_CLOCK 128 int "CPU clock rate [MHz]" 129 depends on !XTENSA_CALIBRATE_CCOUNT 130 default "16" 131 132config GENERIC_CALIBRATE_DELAY 133 bool "Auto calibration of the BogoMIPS value" 134 ---help--- 135 The BogoMIPS value can easily be derived from the CPU frequency. 136 137config CMDLINE_BOOL 138 bool "Default bootloader kernel arguments" 139 140config CMDLINE 141 string "Initial kernel command string" 142 depends on CMDLINE_BOOL 143 default "console=ttyS0,38400 root=/dev/ram" 144 help 145 On some architectures (EBSA110 and CATS), there is currently no way 146 for the boot loader to pass arguments to the kernel. For these 147 architectures, you should supply some command-line options at build 148 time by entering them here. As a minimum, you should specify the 149 memory size and the root device (e.g., mem=64M root=/dev/nfs). 150 151config SERIAL_CONSOLE 152 bool 153 depends on XTENSA_PLATFORM_ISS 154 default y 155 156config XTENSA_ISS_NETWORK 157 bool 158 depends on XTENSA_PLATFORM_ISS 159 default y 160 161source "mm/Kconfig" 162 163endmenu 164 165menu "Bus options" 166 167config PCI 168 bool "PCI support" if !XTENSA_PLATFORM_ISS 169 depends on !XTENSA_PLATFORM_ISS 170 default y 171 help 172 Find out whether you have a PCI motherboard. PCI is the name of a 173 bus system, i.e. the way the CPU talks to the other stuff inside 174 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 175 VESA. If you have PCI, say Y, otherwise N. 176 177 The PCI-HOWTO, available from 178 <http://www.linuxdoc.org/docs.html#howto>, contains valuable 179 information about which PCI hardware does work under Linux and which 180 doesn't 181 182source "drivers/pci/Kconfig" 183 184config HOTPLUG 185 186 bool "Support for hot-pluggable devices" 187 ---help--- 188 Say Y here if you want to plug devices into your computer while 189 the system is running, and be able to use them quickly. In many 190 cases, the devices can likewise be unplugged at any time too. 191 192 One well known example of this is PCMCIA- or PC-cards, credit-card 193 size devices such as network cards, modems or hard drives which are 194 plugged into slots found on all modern laptop computers. Another 195 example, used on modern desktops as well as laptops, is USB. 196 197 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent 198 software (at <http://linux-hotplug.sourceforge.net/>) and install it. 199 Then your kernel will automatically call out to a user mode "policy 200 agent" (/sbin/hotplug) to load modules and set up software needed 201 to use devices as you hotplug them. 202 203source "drivers/pcmcia/Kconfig" 204 205source "drivers/pci/hotplug/Kconfig" 206 207endmenu 208 209menu "Executable file formats" 210 211# only elf supported 212config KCORE_ELF 213 bool 214 depends on PROC_FS 215 default y 216 help 217 If you enabled support for /proc file system then the file 218 /proc/kcore will contain the kernel core image in ELF format. This 219 can be used in gdb: 220 221 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore 222 223 This is especially useful if you have compiled the kernel with the 224 "-g" option to preserve debugging information. It is mainly used 225 for examining kernel data structures on the live kernel. 226 227source "fs/Kconfig.binfmt" 228 229endmenu 230 231source "net/Kconfig" 232 233source "drivers/Kconfig" 234 235source "fs/Kconfig" 236 237menu "Xtensa initrd options" 238 depends on BLK_DEV_INITRD 239 240 config EMBEDDED_RAMDISK 241 bool "Embed root filesystem ramdisk into the kernel" 242 243config EMBEDDED_RAMDISK_IMAGE 244 string "Filename of gzipped ramdisk image" 245 depends on EMBEDDED_RAMDISK 246 default "ramdisk.gz" 247 help 248 This is the filename of the ramdisk image to be built into the 249 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/. 250 The ramdisk image is not part of the kernel distribution; you must 251 provide one yourself. 252endmenu 253 254source "arch/xtensa/Kconfig.debug" 255 256source "security/Kconfig" 257 258source "crypto/Kconfig" 259 260source "lib/Kconfig" 261 262 263