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
55 source "kernel/Kconfig.freezer"
60 config VARIANT_IRQ_SWITCH
63 menu "Processor type and features"
66 prompt "Xtensa Processor Configuration"
67 default XTENSA_VARIANT_FSF
69 config XTENSA_VARIANT_FSF
70 bool "fsf - default (not generic) configuration"
73 config XTENSA_VARIANT_DC232B
74 bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
77 This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
79 config XTENSA_VARIANT_S6000
80 bool "s6000 - Stretch software configurable processor"
81 select VARIANT_IRQ_SWITCH
82 select ARCH_REQUIRE_GPIOLIB
83 select XTENSA_CALIBRATE_CCOUNT
86 config XTENSA_UNALIGNED_USER
87 bool "Unaligned memory access in use space"
89 The Xtensa architecture currently does not handle unaligned
90 memory accesses in hardware but through an exception handler.
91 Per default, unaligned memory accesses are disabled in user space.
93 Say Y here to enable unaligned memory access in user space.
96 bool "Preemptible Kernel"
98 This option reduces the latency of the kernel when reacting to
99 real-time or interactive events by allowing a low priority process to
100 be preempted even if it is in kernel mode executing a system call.
101 Unfortunately the kernel code has some race conditions if both
102 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
103 currently disabled if you are building an SMP kernel.
105 Say Y here if you are building a kernel for a desktop, embedded
106 or real-time system. Say N if you are unsure.
108 config MATH_EMULATION
109 bool "Math emulation"
111 Can we use information of configuration file?
115 config XTENSA_CALIBRATE_CCOUNT
118 On some platforms (XT2000, for example), the CPU clock rate can
119 vary. The frequency can be determined, however, by measuring
120 against a well known, fixed frequency, such as an UART oscillator.
122 config SERIAL_CONSOLE
125 config XTENSA_ISS_NETWORK
134 Find out whether you have a PCI motherboard. PCI is the name of a
135 bus system, i.e. the way the CPU talks to the other stuff inside
136 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
137 VESA. If you have PCI, say Y, otherwise N.
139 source "drivers/pci/Kconfig"
143 menu "Platform options"
146 prompt "Xtensa System Type"
147 default XTENSA_PLATFORM_ISS
149 config XTENSA_PLATFORM_ISS
151 select XTENSA_CALIBRATE_CCOUNT
152 select SERIAL_CONSOLE
153 select XTENSA_ISS_NETWORK
155 ISS is an acronym for Tensilica's Instruction Set Simulator.
157 config XTENSA_PLATFORM_XT2000
160 XT2000 is the name of Tensilica's feature-rich emulation platform.
161 This hardware is capable of running a full Linux distribution.
163 config XTENSA_PLATFORM_S6105
165 select SERIAL_CONSOLE
170 config XTENSA_CPU_CLOCK
171 int "CPU clock rate [MHz]"
172 depends on !XTENSA_CALIBRATE_CCOUNT
175 config GENERIC_CALIBRATE_DELAY
176 bool "Auto calibration of the BogoMIPS value"
178 The BogoMIPS value can easily be derived from the CPU frequency.
181 bool "Default bootloader kernel arguments"
184 string "Initial kernel command string"
185 depends on CMDLINE_BOOL
186 default "console=ttyS0,38400 root=/dev/ram"
188 On some architectures (EBSA110 and CATS), there is currently no way
189 for the boot loader to pass arguments to the kernel. For these
190 architectures, you should supply some command-line options at build
191 time by entering them here. As a minimum, you should specify the
192 memory size and the root device (e.g., mem=64M root=/dev/nfs).
197 bool "Support for hot-pluggable devices"
199 Say Y here if you want to plug devices into your computer while
200 the system is running, and be able to use them quickly. In many
201 cases, the devices can likewise be unplugged at any time too.
203 One well known example of this is PCMCIA- or PC-cards, credit-card
204 size devices such as network cards, modems or hard drives which are
205 plugged into slots found on all modern laptop computers. Another
206 example, used on modern desktops as well as laptops, is USB.
208 Enable HOTPLUG and build a modular kernel. Get agent software
209 (from <http://linux-hotplug.sourceforge.net/>) and install it.
210 Then your kernel will automatically call out to a user mode "policy
211 agent" (/sbin/hotplug) to load modules and set up software needed
212 to use devices as you hotplug them.
214 source "drivers/pcmcia/Kconfig"
216 source "drivers/pci/hotplug/Kconfig"
220 menu "Executable file formats"
227 If you enabled support for /proc file system then the file
228 /proc/kcore will contain the kernel core image in ELF format. This
231 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
233 This is especially useful if you have compiled the kernel with the
234 "-g" option to preserve debugging information. It is mainly used
235 for examining kernel data structures on the live kernel.
237 source "fs/Kconfig.binfmt"
243 source "drivers/Kconfig"
247 menu "Xtensa initrd options"
248 depends on BLK_DEV_INITRD
250 config EMBEDDED_RAMDISK
251 bool "Embed root filesystem ramdisk into the kernel"
253 config EMBEDDED_RAMDISK_IMAGE
254 string "Filename of gzipped ramdisk image"
255 depends on EMBEDDED_RAMDISK
258 This is the filename of the ramdisk image to be built into the
259 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
260 The ramdisk image is not part of the kernel distribution; you must
261 provide one yourself.
264 source "arch/xtensa/Kconfig.debug"
266 source "security/Kconfig"
268 source "crypto/Kconfig"