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
82 config XTENSA_UNALIGNED_USER
83 bool "Unaligned memory access in use space"
85 The Xtensa architecture currently does not handle unaligned
86 memory accesses in hardware but through an exception handler.
87 Per default, unaligned memory accesses are disabled in user space.
89 Say Y here to enable unaligned memory access in user space.
92 bool "Preemptible Kernel"
94 This option reduces the latency of the kernel when reacting to
95 real-time or interactive events by allowing a low priority process to
96 be preempted even if it is in kernel mode executing a system call.
97 Unfortunately the kernel code has some race conditions if both
98 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
99 currently disabled if you are building an SMP kernel.
101 Say Y here if you are building a kernel for a desktop, embedded
102 or real-time system. Say N if you are unsure.
104 config MATH_EMULATION
105 bool "Math emulation"
107 Can we use information of configuration file?
111 config XTENSA_CALIBRATE_CCOUNT
114 On some platforms (XT2000, for example), the CPU clock rate can
115 vary. The frequency can be determined, however, by measuring
116 against a well known, fixed frequency, such as an UART oscillator.
118 config SERIAL_CONSOLE
121 config XTENSA_ISS_NETWORK
130 Find out whether you have a PCI motherboard. PCI is the name of a
131 bus system, i.e. the way the CPU talks to the other stuff inside
132 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
133 VESA. If you have PCI, say Y, otherwise N.
135 source "drivers/pci/Kconfig"
137 menu "Platform options"
140 prompt "Xtensa System Type"
141 default XTENSA_PLATFORM_ISS
143 config XTENSA_PLATFORM_ISS
145 select XTENSA_CALIBRATE_CCOUNT
146 select SERIAL_CONSOLE
147 select XTENSA_ISS_NETWORK
149 ISS is an acronym for Tensilica's Instruction Set Simulator.
151 config XTENSA_PLATFORM_XT2000
153 select XTENSA_CALIBRATE_CCOUNT
156 XT2000 is the name of Tensilica's feature-rich emulation platform.
157 This hardware is capable of running a full Linux distribution.
159 config XTENSA_PLATFORM_S6105
161 select SERIAL_CONSOLE
166 config XTENSA_CPU_CLOCK
167 int "CPU clock rate [MHz]"
168 depends on !XTENSA_CALIBRATE_CCOUNT
171 config GENERIC_CALIBRATE_DELAY
172 bool "Auto calibration of the BogoMIPS value"
174 The BogoMIPS value can easily be derived from the CPU frequency.
177 bool "Default bootloader kernel arguments"
180 string "Initial kernel command string"
181 depends on CMDLINE_BOOL
182 default "console=ttyS0,38400 root=/dev/ram"
184 On some architectures (EBSA110 and CATS), there is currently no way
185 for the boot loader to pass arguments to the kernel. For these
186 architectures, you should supply some command-line options at build
187 time by entering them here. As a minimum, you should specify the
188 memory size and the root device (e.g., mem=64M root=/dev/nfs).
195 bool "Support for hot-pluggable devices"
197 Say Y here if you want to plug devices into your computer while
198 the system is running, and be able to use them quickly. In many
199 cases, the devices can likewise be unplugged at any time too.
201 One well known example of this is PCMCIA- or PC-cards, credit-card
202 size devices such as network cards, modems or hard drives which are
203 plugged into slots found on all modern laptop computers. Another
204 example, used on modern desktops as well as laptops, is USB.
206 Enable HOTPLUG and build a modular kernel. Get agent software
207 (from <http://linux-hotplug.sourceforge.net/>) and install it.
208 Then your kernel will automatically call out to a user mode "policy
209 agent" (/sbin/hotplug) to load modules and set up software needed
210 to use devices as you hotplug them.
212 source "drivers/pcmcia/Kconfig"
214 source "drivers/pci/hotplug/Kconfig"
218 menu "Executable file formats"
225 If you enabled support for /proc file system then the file
226 /proc/kcore will contain the kernel core image in ELF format. This
229 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
231 This is especially useful if you have compiled the kernel with the
232 "-g" option to preserve debugging information. It is mainly used
233 for examining kernel data structures on the live kernel.
235 source "fs/Kconfig.binfmt"
241 source "drivers/Kconfig"
245 menu "Xtensa initrd options"
246 depends on BLK_DEV_INITRD
248 config EMBEDDED_RAMDISK
249 bool "Embed root filesystem ramdisk into the kernel"
251 config EMBEDDED_RAMDISK_IMAGE
252 string "Filename of gzipped ramdisk image"
253 depends on EMBEDDED_RAMDISK
256 This is the filename of the ramdisk image to be built into the
257 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
258 The ramdisk image is not part of the kernel distribution; you must
259 provide one yourself.
262 source "arch/xtensa/Kconfig.debug"
264 source "security/Kconfig"
266 source "crypto/Kconfig"