1 # For a description of the syntax of this configuration file,
2 # see Documentation/kbuild/kconfig-language.txt.
4 mainmenu "Linux/Xtensa Kernel Configuration"
16 Xtensa processors are 32-bit RISC machines designed by Tensilica
17 primarily for embedded systems. These processors are both
18 configurable and extensible. The Linux port to the Xtensa
19 architecture supports all processor configurations and extensions,
20 with reasonable minimum requirements. The Xtensa Linux project has
21 a home page at <http://xtensa.sourceforge.net/>.
23 config RWSEM_XCHGADD_ALGORITHM
26 config GENERIC_FIND_NEXT_BIT
29 config GENERIC_HWEIGHT
32 config GENERIC_HARDIRQS
38 config ARCH_HAS_ILOG2_U32
41 config ARCH_HAS_ILOG2_U64
52 source "kernel/Kconfig.freezer"
57 config VARIANT_IRQ_SWITCH
60 menu "Processor type and features"
63 prompt "Xtensa Processor Configuration"
64 default XTENSA_VARIANT_FSF
66 config XTENSA_VARIANT_FSF
67 bool "fsf - default (not generic) configuration"
70 config XTENSA_VARIANT_DC232B
71 bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
74 This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
76 config XTENSA_VARIANT_S6000
77 bool "s6000 - Stretch software configurable processor"
78 select VARIANT_IRQ_SWITCH
79 select ARCH_REQUIRE_GPIOLIB
80 select XTENSA_CALIBRATE_CCOUNT
83 config XTENSA_UNALIGNED_USER
84 bool "Unaligned memory access in use space"
86 The Xtensa architecture currently does not handle unaligned
87 memory accesses in hardware but through an exception handler.
88 Per default, unaligned memory accesses are disabled in user space.
90 Say Y here to enable unaligned memory access in user space.
93 bool "Preemptible Kernel"
95 This option reduces the latency of the kernel when reacting to
96 real-time or interactive events by allowing a low priority process to
97 be preempted even if it is in kernel mode executing a system call.
98 Unfortunately the kernel code has some race conditions if both
99 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
100 currently disabled if you are building an SMP kernel.
102 Say Y here if you are building a kernel for a desktop, embedded
103 or real-time system. Say N if you are unsure.
105 config MATH_EMULATION
106 bool "Math emulation"
108 Can we use information of configuration file?
112 config XTENSA_CALIBRATE_CCOUNT
115 On some platforms (XT2000, for example), the CPU clock rate can
116 vary. The frequency can be determined, however, by measuring
117 against a well known, fixed frequency, such as an UART oscillator.
119 config SERIAL_CONSOLE
122 config XTENSA_ISS_NETWORK
131 Find out whether you have a PCI motherboard. PCI is the name of a
132 bus system, i.e. the way the CPU talks to the other stuff inside
133 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
134 VESA. If you have PCI, say Y, otherwise N.
136 source "drivers/pci/Kconfig"
140 menu "Platform options"
143 prompt "Xtensa System Type"
144 default XTENSA_PLATFORM_ISS
146 config XTENSA_PLATFORM_ISS
148 select XTENSA_CALIBRATE_CCOUNT
149 select SERIAL_CONSOLE
150 select XTENSA_ISS_NETWORK
152 ISS is an acronym for Tensilica's Instruction Set Simulator.
154 config XTENSA_PLATFORM_XT2000
157 XT2000 is the name of Tensilica's feature-rich emulation platform.
158 This hardware is capable of running a full Linux distribution.
160 config XTENSA_PLATFORM_S6105
162 select SERIAL_CONSOLE
167 config XTENSA_CPU_CLOCK
168 int "CPU clock rate [MHz]"
169 depends on !XTENSA_CALIBRATE_CCOUNT
172 config GENERIC_CALIBRATE_DELAY
173 bool "Auto calibration of the BogoMIPS value"
175 The BogoMIPS value can easily be derived from the CPU frequency.
178 bool "Default bootloader kernel arguments"
181 string "Initial kernel command string"
182 depends on CMDLINE_BOOL
183 default "console=ttyS0,38400 root=/dev/ram"
185 On some architectures (EBSA110 and CATS), there is currently no way
186 for the boot loader to pass arguments to the kernel. For these
187 architectures, you should supply some command-line options at build
188 time by entering them here. As a minimum, you should specify the
189 memory size and the root device (e.g., mem=64M root=/dev/nfs).
194 bool "Support for hot-pluggable devices"
196 Say Y here if you want to plug devices into your computer while
197 the system is running, and be able to use them quickly. In many
198 cases, the devices can likewise be unplugged at any time too.
200 One well known example of this is PCMCIA- or PC-cards, credit-card
201 size devices such as network cards, modems or hard drives which are
202 plugged into slots found on all modern laptop computers. Another
203 example, used on modern desktops as well as laptops, is USB.
205 Enable HOTPLUG and build a modular kernel. Get agent software
206 (from <http://linux-hotplug.sourceforge.net/>) and install it.
207 Then your kernel will automatically call out to a user mode "policy
208 agent" (/sbin/hotplug) to load modules and set up software needed
209 to use devices as you hotplug them.
211 source "drivers/pcmcia/Kconfig"
213 source "drivers/pci/hotplug/Kconfig"
217 menu "Executable file formats"
224 If you enabled support for /proc file system then the file
225 /proc/kcore will contain the kernel core image in ELF format. This
228 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
230 This is especially useful if you have compiled the kernel with the
231 "-g" option to preserve debugging information. It is mainly used
232 for examining kernel data structures on the live kernel.
234 source "fs/Kconfig.binfmt"
240 source "drivers/Kconfig"
244 menu "Xtensa initrd options"
245 depends on BLK_DEV_INITRD
247 config EMBEDDED_RAMDISK
248 bool "Embed root filesystem ramdisk into the kernel"
250 config EMBEDDED_RAMDISK_IMAGE
251 string "Filename of gzipped ramdisk image"
252 depends on EMBEDDED_RAMDISK
255 This is the filename of the ramdisk image to be built into the
256 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
257 The ramdisk image is not part of the kernel distribution; you must
258 provide one yourself.
261 source "arch/xtensa/Kconfig.debug"
263 source "security/Kconfig"
265 source "crypto/Kconfig"