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 XTENSA 11 bool 12 default y 13 help 14 Xtensa processors are 32-bit RISC machines designed by Tensilica 15 primarily for embedded systems. These processors are both 16 configurable and extensible. The Linux port to the Xtensa 17 architecture supports all processor configurations and extensions, 18 with reasonable minimum requirements. The Xtensa Linux project has 19 a home page at <http://xtensa.sourceforge.net/>. 20 21config RWSEM_XCHGADD_ALGORITHM 22 bool 23 default y 24 25config GENERIC_FIND_NEXT_BIT 26 bool 27 default y 28 29config GENERIC_HWEIGHT 30 bool 31 default y 32 33config GENERIC_HARDIRQS 34 bool 35 default y 36 37config RWSEM_GENERIC_SPINLOCK 38 bool 39 default y 40 41source "init/Kconfig" 42 43menu "Processor type and features" 44 45choice 46 prompt "Xtensa Processor Configuration" 47 default XTENSA_CPU_LINUX_BE 48 49config XTENSA_CPU_LINUX_BE 50 bool "linux_be" 51 ---help--- 52 The linux_be processor configuration is the baseline Xtensa 53 configurations included in this kernel and also used by 54 binutils, gcc, and gdb. It contains no TIE, no coprocessors, 55 and the following configuration options: 56 57 Code Density Option 2 Misc Special Registers 58 NSA/NSAU Instructions 128-bit Data Bus Width 59 Processor ID 8K, 2-way I and D Caches 60 Zero-Overhead Loops 2 Inst Address Break Registers 61 Big Endian 2 Data Address Break Registers 62 64 General-Purpose Registers JTAG Interface and Trace Port 63 17 Interrupts MMU w/ TLBs and Autorefill 64 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs) 65 3 Timers Unaligned Exceptions 66endchoice 67 68config MMU 69 bool 70 default y 71 72config XTENSA_UNALIGNED_USER 73 bool "Unaligned memory access in use space" 74 ---help--- 75 The Xtensa architecture currently does not handle unaligned 76 memory accesses in hardware but through an exception handler. 77 Per default, unaligned memory accesses are disabled in user space. 78 79 Say Y here to enable unaligned memory access in user space. 80 81config PREEMPT 82 bool "Preemptible Kernel" 83 ---help--- 84 This option reduces the latency of the kernel when reacting to 85 real-time or interactive events by allowing a low priority process to 86 be preempted even if it is in kernel mode executing a system call. 87 Unfortunately the kernel code has some race conditions if both 88 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is 89 currently disabled if you are building an SMP kernel. 90 91 Say Y here if you are building a kernel for a desktop, embedded 92 or real-time system. Say N if you are unsure. 93 94config MATH_EMULATION 95 bool "Math emulation" 96 help 97 Can we use information of configuration file? 98 99config HIGHMEM 100 bool "High memory support" 101 102endmenu 103 104menu "Platform options" 105 106choice 107 prompt "Xtensa System Type" 108 default XTENSA_PLATFORM_ISS 109 110config XTENSA_PLATFORM_ISS 111 bool "ISS" 112 help 113 ISS is an acronym for Tensilica's Instruction Set Simulator. 114 115config XTENSA_PLATFORM_XT2000 116 bool "XT2000" 117 help 118 XT2000 is the name of Tensilica's feature-rich emulation platform. 119 This hardware is capable of running a full Linux distribution. 120 121endchoice 122 123 124config XTENSA_CALIBRATE_CCOUNT 125 bool "Auto calibration of the CPU clock rate" 126 ---help--- 127 On some platforms (XT2000, for example), the CPU clock rate can 128 vary. The frequency can be determined, however, by measuring 129 against a well known, fixed frequency, such as an UART oscillator. 130 131config XTENSA_CPU_CLOCK 132 int "CPU clock rate [MHz]" 133 depends on !XTENSA_CALIBRATE_CCOUNT 134 default "16" 135 136config GENERIC_CALIBRATE_DELAY 137 bool "Auto calibration of the BogoMIPS value" 138 ---help--- 139 The BogoMIPS value can easily be derived from the CPU frequency. 140 141config CMDLINE_BOOL 142 bool "Default bootloader kernel arguments" 143 144config CMDLINE 145 string "Initial kernel command string" 146 depends on CMDLINE_BOOL 147 default "console=ttyS0,38400 root=/dev/ram" 148 help 149 On some architectures (EBSA110 and CATS), there is currently no way 150 for the boot loader to pass arguments to the kernel. For these 151 architectures, you should supply some command-line options at build 152 time by entering them here. As a minimum, you should specify the 153 memory size and the root device (e.g., mem=64M root=/dev/nfs). 154 155config SERIAL_CONSOLE 156 bool 157 depends on XTENSA_PLATFORM_ISS 158 default y 159 160config XTENSA_ISS_NETWORK 161 bool 162 depends on XTENSA_PLATFORM_ISS 163 default y 164 165source "mm/Kconfig" 166 167endmenu 168 169menu "Bus options" 170 171config PCI 172 bool "PCI support" if !XTENSA_PLATFORM_ISS 173 depends on !XTENSA_PLATFORM_ISS 174 default y 175 help 176 Find out whether you have a PCI motherboard. PCI is the name of a 177 bus system, i.e. the way the CPU talks to the other stuff inside 178 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 179 VESA. If you have PCI, say Y, otherwise N. 180 181 The PCI-HOWTO, available from 182 <http://www.linuxdoc.org/docs.html#howto>, contains valuable 183 information about which PCI hardware does work under Linux and which 184 doesn't 185 186source "drivers/pci/Kconfig" 187 188config HOTPLUG 189 190 bool "Support for hot-pluggable devices" 191 ---help--- 192 Say Y here if you want to plug devices into your computer while 193 the system is running, and be able to use them quickly. In many 194 cases, the devices can likewise be unplugged at any time too. 195 196 One well known example of this is PCMCIA- or PC-cards, credit-card 197 size devices such as network cards, modems or hard drives which are 198 plugged into slots found on all modern laptop computers. Another 199 example, used on modern desktops as well as laptops, is USB. 200 201 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent 202 software (at <http://linux-hotplug.sourceforge.net/>) and install it. 203 Then your kernel will automatically call out to a user mode "policy 204 agent" (/sbin/hotplug) to load modules and set up software needed 205 to use devices as you hotplug them. 206 207source "drivers/pcmcia/Kconfig" 208 209source "drivers/pci/hotplug/Kconfig" 210 211endmenu 212 213menu "Exectuable file formats" 214 215# only elf supported 216config KCORE_ELF 217 bool 218 depends on PROC_FS 219 default y 220 help 221 If you enabled support for /proc file system then the file 222 /proc/kcore will contain the kernel core image in ELF format. This 223 can be used in gdb: 224 225 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore 226 227 This is especially useful if you have compiled the kernel with the 228 "-g" option to preserve debugging information. It is mainly used 229 for examining kernel data structures on the live kernel. 230 231source "fs/Kconfig.binfmt" 232 233endmenu 234 235source "net/Kconfig" 236 237source "drivers/Kconfig" 238 239source "fs/Kconfig" 240 241menu "Xtensa initrd options" 242 depends on BLK_DEV_INITRD 243 244 config EMBEDDED_RAMDISK 245 bool "Embed root filesystem ramdisk into the kernel" 246 247config EMBEDDED_RAMDISK_IMAGE 248 string "Filename of gziped ramdisk image" 249 depends on EMBEDDED_RAMDISK 250 default "ramdisk.gz" 251 help 252 This is the filename of the ramdisk image to be built into the 253 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/. 254 The ramdisk image is not part of the kernel distribution; you must 255 provide one yourself. 256endmenu 257 258source "arch/xtensa/Kconfig.debug" 259 260source "security/Kconfig" 261 262source "crypto/Kconfig" 263 264source "lib/Kconfig" 265 266 267