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 UID16 22 bool 23 default n 24 25config RWSEM_XCHGADD_ALGORITHM 26 bool 27 default y 28 29config GENERIC_HARDIRQS 30 bool 31 default y 32 33source "init/Kconfig" 34 35menu "Processor type and features" 36 37choice 38 prompt "Xtensa Processor Configuration" 39 default XTENSA_CPU_LINUX_BE 40 41config XTENSA_CPU_LINUX_BE 42 bool "linux_be" 43 ---help--- 44 The linux_be processor configuration is the baseline Xtensa 45 configurations included in this kernel and also used by 46 binutils, gcc, and gdb. It contains no TIE, no coprocessors, 47 and the following configuration options: 48 49 Code Density Option 2 Misc Special Registers 50 NSA/NSAU Instructions 128-bit Data Bus Width 51 Processor ID 8K, 2-way I and D Caches 52 Zero-Overhead Loops 2 Inst Address Break Registers 53 Big Endian 2 Data Address Break Registers 54 64 General-Purpose Registers JTAG Interface and Trace Port 55 17 Interrupts MMU w/ TLBs and Autorefill 56 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs) 57 3 Timers Unaligned Exceptions 58endchoice 59 60config MMU 61 bool 62 default y 63 64config XTENSA_UNALIGNED_USER 65 bool "Unaligned memory access in use space" 66 ---help--- 67 The Xtensa architecture currently does not handle unaligned 68 memory accesses in hardware but through an exception handler. 69 Per default, unaligned memory accesses are disabled in user space. 70 71 Say Y here to enable unaligned memory access in user space. 72 73config PREEMPT 74 bool "Preemptible Kernel" 75 ---help--- 76 This option reduces the latency of the kernel when reacting to 77 real-time or interactive events by allowing a low priority process to 78 be preempted even if it is in kernel mode executing a system call. 79 Unfortunately the kernel code has some race conditions if both 80 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is 81 currently disabled if you are building an SMP kernel. 82 83 Say Y here if you are building a kernel for a desktop, embedded 84 or real-time system. Say N if you are unsure. 85 86config MATH_EMULATION 87 bool "Math emulation" 88 help 89 Can we use information of configuration file? 90 91config HIGHMEM 92 bool "High memory support" 93 94endmenu 95 96menu "Platform options" 97 98choice 99 prompt "Xtensa System Type" 100 default XTENSA_PLATFORM_ISS 101 102config XTENSA_PLATFORM_ISS 103 bool "ISS" 104 help 105 ISS is an acronym for Tensilica's Instruction Set Simulator. 106 107config XTENSA_PLATFORM_XT2000 108 bool "XT2000" 109 help 110 XT2000 is the name of Tensilica's feature-rich emulation platform. 111 This hardware is capable of running a full Linux distribution. 112 113endchoice 114 115 116config XTENSA_CALIBRATE_CCOUNT 117 bool "Auto calibration of the CPU clock rate" 118 ---help--- 119 On some platforms (XT2000, for example), the CPU clock rate can 120 vary. The frequency can be determined, however, by measuring 121 against a well known, fixed frequency, such as an UART oscillator. 122 123config XTENSA_CPU_CLOCK 124 int "CPU clock rate [MHz]" 125 depends on !XTENSA_CALIBRATE_CCOUNT 126 default "16" 127 128config GENERIC_CALIBRATE_DELAY 129 bool "Auto calibration of the BogoMIPS value" 130 ---help--- 131 The BogoMIPS value can easily be derived from the CPU frequency. 132 133config CMDLINE_BOOL 134 bool "Default bootloader kernel arguments" 135 136config CMDLINE 137 string "Initial kernel command string" 138 depends on CMDLINE_BOOL 139 default "console=ttyS0,38400 root=/dev/ram" 140 help 141 On some architectures (EBSA110 and CATS), there is currently no way 142 for the boot loader to pass arguments to the kernel. For these 143 architectures, you should supply some command-line options at build 144 time by entering them here. As a minimum, you should specify the 145 memory size and the root device (e.g., mem=64M root=/dev/nfs). 146 147config SERIAL_CONSOLE 148 bool 149 depends on XTENSA_PLATFORM_ISS 150 default y 151 152config XTENSA_ISS_NETWORK 153 bool 154 depends on XTENSA_PLATFORM_ISS 155 default y 156 157source "mm/Kconfig" 158 159endmenu 160 161menu "Bus options" 162 163config PCI 164 bool "PCI support" if !XTENSA_PLATFORM_ISS 165 depends on !XTENSA_PLATFORM_ISS 166 default y 167 help 168 Find out whether you have a PCI motherboard. PCI is the name of a 169 bus system, i.e. the way the CPU talks to the other stuff inside 170 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 171 VESA. If you have PCI, say Y, otherwise N. 172 173 The PCI-HOWTO, available from 174 <http://www.linuxdoc.org/docs.html#howto>, contains valuable 175 information about which PCI hardware does work under Linux and which 176 doesn't 177 178source "drivers/pci/Kconfig" 179 180config HOTPLUG 181 182 bool "Support for hot-pluggable devices" 183 ---help--- 184 Say Y here if you want to plug devices into your computer while 185 the system is running, and be able to use them quickly. In many 186 cases, the devices can likewise be unplugged at any time too. 187 188 One well known example of this is PCMCIA- or PC-cards, credit-card 189 size devices such as network cards, modems or hard drives which are 190 plugged into slots found on all modern laptop computers. Another 191 example, used on modern desktops as well as laptops, is USB. 192 193 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent 194 software (at <http://linux-hotplug.sourceforge.net/>) and install it. 195 Then your kernel will automatically call out to a user mode "policy 196 agent" (/sbin/hotplug) to load modules and set up software needed 197 to use devices as you hotplug them. 198 199source "drivers/pcmcia/Kconfig" 200 201source "drivers/pci/hotplug/Kconfig" 202 203endmenu 204 205menu "Exectuable file formats" 206 207# only elf supported 208config KCORE_ELF 209 bool 210 depends on PROC_FS 211 default y 212 help 213 If you enabled support for /proc file system then the file 214 /proc/kcore will contain the kernel core image in ELF format. This 215 can be used in gdb: 216 217 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore 218 219 This is especially useful if you have compiled the kernel with the 220 "-g" option to preserve debugging information. It is mainly used 221 for examining kernel data structures on the live kernel. 222 223source "fs/Kconfig.binfmt" 224 225endmenu 226 227source "net/Kconfig" 228 229source "drivers/Kconfig" 230 231source "fs/Kconfig" 232 233menu "Xtensa initrd options" 234 depends on BLK_DEV_INITRD 235 236 config EMBEDDED_RAMDISK 237 bool "Embed root filesystem ramdisk into the kernel" 238 239config EMBEDDED_RAMDISK_IMAGE 240 string "Filename of gziped ramdisk image" 241 depends on EMBEDDED_RAMDISK 242 default "ramdisk.gz" 243 help 244 This is the filename of the ramdisk image to be built into the 245 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/. 246 The ramdisk image is not part of the kernel distribution; you must 247 provide one yourself. 248endmenu 249 250source "arch/xtensa/Kconfig.debug" 251 252source "security/Kconfig" 253 254source "crypto/Kconfig" 255 256source "lib/Kconfig" 257 258 259