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
85 config XTENSA_UNALIGNED_USER
86 bool "Unaligned memory access in use space"
88 The Xtensa architecture currently does not handle unaligned
89 memory accesses in hardware but through an exception handler.
90 Per default, unaligned memory accesses are disabled in user space.
92 Say Y here to enable unaligned memory access in user space.
95 bool "Preemptible Kernel"
97 This option reduces the latency of the kernel when reacting to
98 real-time or interactive events by allowing a low priority process to
99 be preempted even if it is in kernel mode executing a system call.
100 Unfortunately the kernel code has some race conditions if both
101 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
102 currently disabled if you are building an SMP kernel.
104 Say Y here if you are building a kernel for a desktop, embedded
105 or real-time system. Say N if you are unsure.
107 config MATH_EMULATION
108 bool "Math emulation"
110 Can we use information of configuration file?
114 config XTENSA_CALIBRATE_CCOUNT
117 On some platforms (XT2000, for example), the CPU clock rate can
118 vary. The frequency can be determined, however, by measuring
119 against a well known, fixed frequency, such as an UART oscillator.
121 config SERIAL_CONSOLE
124 config XTENSA_ISS_NETWORK
133 Find out whether you have a PCI motherboard. PCI is the name of a
134 bus system, i.e. the way the CPU talks to the other stuff inside
135 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
136 VESA. If you have PCI, say Y, otherwise N.
138 source "drivers/pci/Kconfig"
142 menu "Platform options"
145 prompt "Xtensa System Type"
146 default XTENSA_PLATFORM_ISS
148 config XTENSA_PLATFORM_ISS
150 select XTENSA_CALIBRATE_CCOUNT
151 select SERIAL_CONSOLE
152 select XTENSA_ISS_NETWORK
154 ISS is an acronym for Tensilica's Instruction Set Simulator.
156 config XTENSA_PLATFORM_XT2000
159 XT2000 is the name of Tensilica's feature-rich emulation platform.
160 This hardware is capable of running a full Linux distribution.
162 config XTENSA_PLATFORM_S6105
164 select SERIAL_CONSOLE
169 config XTENSA_CPU_CLOCK
170 int "CPU clock rate [MHz]"
171 depends on !XTENSA_CALIBRATE_CCOUNT
174 config GENERIC_CALIBRATE_DELAY
175 bool "Auto calibration of the BogoMIPS value"
177 The BogoMIPS value can easily be derived from the CPU frequency.
180 bool "Default bootloader kernel arguments"
183 string "Initial kernel command string"
184 depends on CMDLINE_BOOL
185 default "console=ttyS0,38400 root=/dev/ram"
187 On some architectures (EBSA110 and CATS), there is currently no way
188 for the boot loader to pass arguments to the kernel. For these
189 architectures, you should supply some command-line options at build
190 time by entering them here. As a minimum, you should specify the
191 memory size and the root device (e.g., mem=64M root=/dev/nfs).
196 bool "Support for hot-pluggable devices"
198 Say Y here if you want to plug devices into your computer while
199 the system is running, and be able to use them quickly. In many
200 cases, the devices can likewise be unplugged at any time too.
202 One well known example of this is PCMCIA- or PC-cards, credit-card
203 size devices such as network cards, modems or hard drives which are
204 plugged into slots found on all modern laptop computers. Another
205 example, used on modern desktops as well as laptops, is USB.
207 Enable HOTPLUG and build a modular kernel. Get agent software
208 (from <http://linux-hotplug.sourceforge.net/>) and install it.
209 Then your kernel will automatically call out to a user mode "policy
210 agent" (/sbin/hotplug) to load modules and set up software needed
211 to use devices as you hotplug them.
213 source "drivers/pcmcia/Kconfig"
215 source "drivers/pci/hotplug/Kconfig"
219 menu "Executable file formats"
226 If you enabled support for /proc file system then the file
227 /proc/kcore will contain the kernel core image in ELF format. This
230 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
232 This is especially useful if you have compiled the kernel with the
233 "-g" option to preserve debugging information. It is mainly used
234 for examining kernel data structures on the live kernel.
236 source "fs/Kconfig.binfmt"
242 source "drivers/Kconfig"
246 menu "Xtensa initrd options"
247 depends on BLK_DEV_INITRD
249 config EMBEDDED_RAMDISK
250 bool "Embed root filesystem ramdisk into the kernel"
252 config EMBEDDED_RAMDISK_IMAGE
253 string "Filename of gzipped ramdisk image"
254 depends on EMBEDDED_RAMDISK
257 This is the filename of the ramdisk image to be built into the
258 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
259 The ramdisk image is not part of the kernel distribution; you must
260 provide one yourself.
263 source "arch/xtensa/Kconfig.debug"
265 source "security/Kconfig"
267 source "crypto/Kconfig"