11 Xtensa processors are 32-bit RISC machines designed by Tensilica
12 primarily for embedded systems. These processors are both
13 configurable and extensible. The Linux port to the Xtensa
14 architecture supports all processor configurations and extensions,
15 with reasonable minimum requirements. The Xtensa Linux project has
16 a home page at <http://xtensa.sourceforge.net/>.
18 config RWSEM_XCHGADD_ALGORITHM
21 config GENERIC_FIND_NEXT_BIT
24 config GENERIC_HWEIGHT
27 config GENERIC_HARDIRQS
33 config ARCH_HAS_ILOG2_U32
36 config ARCH_HAS_ILOG2_U64
47 source "kernel/Kconfig.freezer"
52 config VARIANT_IRQ_SWITCH
55 menu "Processor type and features"
58 prompt "Xtensa Processor Configuration"
59 default XTENSA_VARIANT_FSF
61 config XTENSA_VARIANT_FSF
62 bool "fsf - default (not generic) configuration"
65 config XTENSA_VARIANT_DC232B
66 bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
69 This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
71 config XTENSA_VARIANT_S6000
72 bool "s6000 - Stretch software configurable processor"
73 select VARIANT_IRQ_SWITCH
74 select ARCH_REQUIRE_GPIOLIB
75 select XTENSA_CALIBRATE_CCOUNT
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?
107 config XTENSA_CALIBRATE_CCOUNT
110 On some platforms (XT2000, for example), the CPU clock rate can
111 vary. The frequency can be determined, however, by measuring
112 against a well known, fixed frequency, such as an UART oscillator.
114 config SERIAL_CONSOLE
117 config XTENSA_ISS_NETWORK
126 Find out whether you have a PCI motherboard. PCI is the name of a
127 bus system, i.e. the way the CPU talks to the other stuff inside
128 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
129 VESA. If you have PCI, say Y, otherwise N.
131 source "drivers/pci/Kconfig"
135 menu "Platform options"
138 prompt "Xtensa System Type"
139 default XTENSA_PLATFORM_ISS
141 config XTENSA_PLATFORM_ISS
143 select XTENSA_CALIBRATE_CCOUNT
144 select SERIAL_CONSOLE
145 select XTENSA_ISS_NETWORK
147 ISS is an acronym for Tensilica's Instruction Set Simulator.
149 config XTENSA_PLATFORM_XT2000
152 XT2000 is the name of Tensilica's feature-rich emulation platform.
153 This hardware is capable of running a full Linux distribution.
155 config XTENSA_PLATFORM_S6105
157 select SERIAL_CONSOLE
162 config XTENSA_CPU_CLOCK
163 int "CPU clock rate [MHz]"
164 depends on !XTENSA_CALIBRATE_CCOUNT
167 config GENERIC_CALIBRATE_DELAY
168 bool "Auto calibration of the BogoMIPS value"
170 The BogoMIPS value can easily be derived from the CPU frequency.
173 bool "Default bootloader kernel arguments"
176 string "Initial kernel command string"
177 depends on CMDLINE_BOOL
178 default "console=ttyS0,38400 root=/dev/ram"
180 On some architectures (EBSA110 and CATS), there is currently no way
181 for the boot loader to pass arguments to the kernel. For these
182 architectures, you should supply some command-line options at build
183 time by entering them here. As a minimum, you should specify the
184 memory size and the root device (e.g., mem=64M root=/dev/nfs).
189 bool "Support for hot-pluggable devices"
191 Say Y here if you want to plug devices into your computer while
192 the system is running, and be able to use them quickly. In many
193 cases, the devices can likewise be unplugged at any time too.
195 One well known example of this is PCMCIA- or PC-cards, credit-card
196 size devices such as network cards, modems or hard drives which are
197 plugged into slots found on all modern laptop computers. Another
198 example, used on modern desktops as well as laptops, is USB.
200 Enable HOTPLUG and build a modular kernel. Get agent software
201 (from <http://linux-hotplug.sourceforge.net/>) and install it.
202 Then your kernel will automatically call out to a user mode "policy
203 agent" (/sbin/hotplug) to load modules and set up software needed
204 to use devices as you hotplug them.
206 source "drivers/pcmcia/Kconfig"
208 source "drivers/pci/hotplug/Kconfig"
212 menu "Executable file formats"
219 If you enabled support for /proc file system then the file
220 /proc/kcore will contain the kernel core image in ELF format. This
223 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
225 This is especially useful if you have compiled the kernel with the
226 "-g" option to preserve debugging information. It is mainly used
227 for examining kernel data structures on the live kernel.
229 source "fs/Kconfig.binfmt"
235 source "drivers/Kconfig"
239 menu "Xtensa initrd options"
240 depends on BLK_DEV_INITRD
242 config EMBEDDED_RAMDISK
243 bool "Embed root filesystem ramdisk into the kernel"
245 config EMBEDDED_RAMDISK_IMAGE
246 string "Filename of gzipped ramdisk image"
247 depends on EMBEDDED_RAMDISK
250 This is the filename of the ramdisk image to be built into the
251 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
252 The ramdisk image is not part of the kernel distribution; you must
253 provide one yourself.
256 source "arch/xtensa/Kconfig.debug"
258 source "security/Kconfig"
260 source "crypto/Kconfig"