1 # For a description of the syntax of this configuration file,
2 # see Documentation/kbuild/kconfig-language.txt.
4 mainmenu "Linux/Xtensa Kernel Configuration"
19 Xtensa processors are 32-bit RISC machines designed by Tensilica
20 primarily for embedded systems. These processors are both
21 configurable and extensible. The Linux port to the Xtensa
22 architecture supports all processor configurations and extensions,
23 with reasonable minimum requirements. The Xtensa Linux project has
24 a home page at <http://xtensa.sourceforge.net/>.
26 config RWSEM_XCHGADD_ALGORITHM
30 config GENERIC_FIND_NEXT_BIT
34 config GENERIC_HWEIGHT
38 config GENERIC_HARDIRQS
42 config ARCH_HAS_ILOG2_U32
46 config ARCH_HAS_ILOG2_U64
59 menu "Processor type and features"
62 prompt "Xtensa Processor Configuration"
63 default XTENSA_VARIANT_FSF
65 config XTENSA_VARIANT_FSF
66 bool "fsf - default (not generic) configuration"
68 config XTENSA_VARIANT_DC232B
69 bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
71 This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
78 config XTENSA_UNALIGNED_USER
79 bool "Unaligned memory access in use space"
81 The Xtensa architecture currently does not handle unaligned
82 memory accesses in hardware but through an exception handler.
83 Per default, unaligned memory accesses are disabled in user space.
85 Say Y here to enable unaligned memory access in user space.
88 bool "Preemptible Kernel"
90 This option reduces the latency of the kernel when reacting to
91 real-time or interactive events by allowing a low priority process to
92 be preempted even if it is in kernel mode executing a system call.
93 Unfortunately the kernel code has some race conditions if both
94 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
95 currently disabled if you are building an SMP kernel.
97 Say Y here if you are building a kernel for a desktop, embedded
98 or real-time system. Say N if you are unsure.
100 config MATH_EMULATION
101 bool "Math emulation"
103 Can we use information of configuration file?
106 bool "High memory support"
110 menu "Platform options"
113 prompt "Xtensa System Type"
114 default XTENSA_PLATFORM_ISS
116 config XTENSA_PLATFORM_ISS
119 ISS is an acronym for Tensilica's Instruction Set Simulator.
121 config XTENSA_PLATFORM_XT2000
124 XT2000 is the name of Tensilica's feature-rich emulation platform.
125 This hardware is capable of running a full Linux distribution.
130 config XTENSA_CALIBRATE_CCOUNT
131 bool "Auto calibration of the CPU clock rate"
133 On some platforms (XT2000, for example), the CPU clock rate can
134 vary. The frequency can be determined, however, by measuring
135 against a well known, fixed frequency, such as an UART oscillator.
137 config XTENSA_CPU_CLOCK
138 int "CPU clock rate [MHz]"
139 depends on !XTENSA_CALIBRATE_CCOUNT
142 config GENERIC_CALIBRATE_DELAY
143 bool "Auto calibration of the BogoMIPS value"
145 The BogoMIPS value can easily be derived from the CPU frequency.
148 bool "Default bootloader kernel arguments"
151 string "Initial kernel command string"
152 depends on CMDLINE_BOOL
153 default "console=ttyS0,38400 root=/dev/ram"
155 On some architectures (EBSA110 and CATS), there is currently no way
156 for the boot loader to pass arguments to the kernel. For these
157 architectures, you should supply some command-line options at build
158 time by entering them here. As a minimum, you should specify the
159 memory size and the root device (e.g., mem=64M root=/dev/nfs).
161 config SERIAL_CONSOLE
163 depends on XTENSA_PLATFORM_ISS
166 config XTENSA_ISS_NETWORK
168 depends on XTENSA_PLATFORM_ISS
178 bool "PCI support" if !XTENSA_PLATFORM_ISS
179 depends on !XTENSA_PLATFORM_ISS
182 Find out whether you have a PCI motherboard. PCI is the name of a
183 bus system, i.e. the way the CPU talks to the other stuff inside
184 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
185 VESA. If you have PCI, say Y, otherwise N.
187 source "drivers/pci/Kconfig"
191 bool "Support for hot-pluggable devices"
193 Say Y here if you want to plug devices into your computer while
194 the system is running, and be able to use them quickly. In many
195 cases, the devices can likewise be unplugged at any time too.
197 One well known example of this is PCMCIA- or PC-cards, credit-card
198 size devices such as network cards, modems or hard drives which are
199 plugged into slots found on all modern laptop computers. Another
200 example, used on modern desktops as well as laptops, is USB.
202 Enable HOTPLUG and build a modular kernel. Get agent software
203 (from <http://linux-hotplug.sourceforge.net/>) and install it.
204 Then your kernel will automatically call out to a user mode "policy
205 agent" (/sbin/hotplug) to load modules and set up software needed
206 to use devices as you hotplug them.
208 source "drivers/pcmcia/Kconfig"
210 source "drivers/pci/hotplug/Kconfig"
214 menu "Executable file formats"
222 If you enabled support for /proc file system then the file
223 /proc/kcore will contain the kernel core image in ELF format. This
226 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
228 This is especially useful if you have compiled the kernel with the
229 "-g" option to preserve debugging information. It is mainly used
230 for examining kernel data structures on the live kernel.
232 source "fs/Kconfig.binfmt"
238 source "drivers/Kconfig"
242 menu "Xtensa initrd options"
243 depends on BLK_DEV_INITRD
245 config EMBEDDED_RAMDISK
246 bool "Embed root filesystem ramdisk into the kernel"
248 config EMBEDDED_RAMDISK_IMAGE
249 string "Filename of gzipped ramdisk image"
250 depends on EMBEDDED_RAMDISK
253 This is the filename of the ramdisk image to be built into the
254 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
255 The ramdisk image is not part of the kernel distribution; you must
256 provide one yourself.
259 source "arch/xtensa/Kconfig.debug"
261 source "security/Kconfig"
263 source "crypto/Kconfig"