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
35 config ARCH_HAS_ILOG2_U32
38 config ARCH_HAS_ILOG2_U64
49 source "kernel/Kconfig.freezer"
54 config VARIANT_IRQ_SWITCH
57 menu "Processor type and features"
60 prompt "Xtensa Processor Configuration"
61 default XTENSA_VARIANT_FSF
63 config XTENSA_VARIANT_FSF
64 bool "fsf - default (not generic) configuration"
67 config XTENSA_VARIANT_DC232B
68 bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
71 This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
74 config XTENSA_UNALIGNED_USER
75 bool "Unaligned memory access in use space"
77 The Xtensa architecture currently does not handle unaligned
78 memory accesses in hardware but through an exception handler.
79 Per default, unaligned memory accesses are disabled in user space.
81 Say Y here to enable unaligned memory access in user space.
84 bool "Preemptible Kernel"
86 This option reduces the latency of the kernel when reacting to
87 real-time or interactive events by allowing a low priority process to
88 be preempted even if it is in kernel mode executing a system call.
89 Unfortunately the kernel code has some race conditions if both
90 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
91 currently disabled if you are building an SMP kernel.
93 Say Y here if you are building a kernel for a desktop, embedded
94 or real-time system. Say N if you are unsure.
99 Can we use information of configuration file?
103 config XTENSA_CALIBRATE_CCOUNT
106 On some platforms (XT2000, for example), the CPU clock rate can
107 vary. The frequency can be determined, however, by measuring
108 against a well known, fixed frequency, such as an UART oscillator.
110 config SERIAL_CONSOLE
113 config XTENSA_ISS_NETWORK
122 Find out whether you have a PCI motherboard. PCI is the name of a
123 bus system, i.e. the way the CPU talks to the other stuff inside
124 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
125 VESA. If you have PCI, say Y, otherwise N.
127 source "drivers/pci/Kconfig"
129 menu "Platform options"
132 prompt "Xtensa System Type"
133 default XTENSA_PLATFORM_ISS
135 config XTENSA_PLATFORM_ISS
137 select XTENSA_CALIBRATE_CCOUNT
138 select SERIAL_CONSOLE
139 select XTENSA_ISS_NETWORK
141 ISS is an acronym for Tensilica's Instruction Set Simulator.
143 config XTENSA_PLATFORM_XT2000
145 select XTENSA_CALIBRATE_CCOUNT
148 XT2000 is the name of Tensilica's feature-rich emulation platform.
149 This hardware is capable of running a full Linux distribution.
154 config XTENSA_CPU_CLOCK
155 int "CPU clock rate [MHz]"
156 depends on !XTENSA_CALIBRATE_CCOUNT
159 config GENERIC_CALIBRATE_DELAY
160 bool "Auto calibration of the BogoMIPS value"
162 The BogoMIPS value can easily be derived from the CPU frequency.
165 bool "Default bootloader kernel arguments"
168 string "Initial kernel command string"
169 depends on CMDLINE_BOOL
170 default "console=ttyS0,38400 root=/dev/ram"
172 On some architectures (EBSA110 and CATS), there is currently no way
173 for the boot loader to pass arguments to the kernel. For these
174 architectures, you should supply some command-line options at build
175 time by entering them here. As a minimum, you should specify the
176 memory size and the root device (e.g., mem=64M root=/dev/nfs).
183 bool "Support for hot-pluggable devices"
185 Say Y here if you want to plug devices into your computer while
186 the system is running, and be able to use them quickly. In many
187 cases, the devices can likewise be unplugged at any time too.
189 One well known example of this is PCMCIA- or PC-cards, credit-card
190 size devices such as network cards, modems or hard drives which are
191 plugged into slots found on all modern laptop computers. Another
192 example, used on modern desktops as well as laptops, is USB.
194 Enable HOTPLUG and build a modular kernel. Get agent software
195 (from <http://linux-hotplug.sourceforge.net/>) and install it.
196 Then your kernel will automatically call out to a user mode "policy
197 agent" (/sbin/hotplug) to load modules and set up software needed
198 to use devices as you hotplug them.
200 source "drivers/pcmcia/Kconfig"
202 source "drivers/pci/hotplug/Kconfig"
206 menu "Executable file formats"
213 If you enabled support for /proc file system then the file
214 /proc/kcore will contain the kernel core image in ELF format. This
217 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
219 This is especially useful if you have compiled the kernel with the
220 "-g" option to preserve debugging information. It is mainly used
221 for examining kernel data structures on the live kernel.
223 source "fs/Kconfig.binfmt"
229 source "drivers/Kconfig"
233 menu "Xtensa initrd options"
234 depends on BLK_DEV_INITRD
236 config EMBEDDED_RAMDISK
237 bool "Embed root filesystem ramdisk into the kernel"
239 config EMBEDDED_RAMDISK_IMAGE
240 string "Filename of gzipped ramdisk image"
241 depends on EMBEDDED_RAMDISK
244 This is the filename of the ramdisk image to be built into the
245 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
246 The ramdisk image is not part of the kernel distribution; you must
247 provide one yourself.
250 source "arch/xtensa/Kconfig.debug"
252 source "security/Kconfig"
254 source "crypto/Kconfig"