1 # For a description of the syntax of this configuration file,
2 # see Documentation/kbuild/config-language.txt.
4 mainmenu "Linux/Xtensa Kernel Configuration"
14 Xtensa processors are 32-bit RISC machines designed by Tensilica
15 primarily for embedded systems. These processors are both
16 configurable and extensible. The Linux port to the Xtensa
17 architecture supports all processor configurations and extensions,
18 with reasonable minimum requirements. The Xtensa Linux project has
19 a home page at <http://xtensa.sourceforge.net/>.
21 config RWSEM_XCHGADD_ALGORITHM
25 config GENERIC_FIND_NEXT_BIT
29 config GENERIC_HWEIGHT
33 config GENERIC_HARDIRQS
37 config ARCH_HAS_ILOG2_U32
41 config ARCH_HAS_ILOG2_U64
47 menu "Processor type and features"
50 prompt "Xtensa Processor Configuration"
51 default XTENSA_CPU_LINUX_BE
53 config XTENSA_CPU_LINUX_BE
56 The linux_be processor configuration is the baseline Xtensa
57 configurations included in this kernel and also used by
58 binutils, gcc, and gdb. It contains no TIE, no coprocessors,
59 and the following configuration options:
61 Code Density Option 2 Misc Special Registers
62 NSA/NSAU Instructions 128-bit Data Bus Width
63 Processor ID 8K, 2-way I and D Caches
64 Zero-Overhead Loops 2 Inst Address Break Registers
65 Big Endian 2 Data Address Break Registers
66 64 General-Purpose Registers JTAG Interface and Trace Port
67 17 Interrupts MMU w/ TLBs and Autorefill
68 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs)
69 3 Timers Unaligned Exceptions
76 config XTENSA_UNALIGNED_USER
77 bool "Unaligned memory access in use space"
79 The Xtensa architecture currently does not handle unaligned
80 memory accesses in hardware but through an exception handler.
81 Per default, unaligned memory accesses are disabled in user space.
83 Say Y here to enable unaligned memory access in user space.
86 bool "Preemptible Kernel"
88 This option reduces the latency of the kernel when reacting to
89 real-time or interactive events by allowing a low priority process to
90 be preempted even if it is in kernel mode executing a system call.
91 Unfortunately the kernel code has some race conditions if both
92 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
93 currently disabled if you are building an SMP kernel.
95 Say Y here if you are building a kernel for a desktop, embedded
96 or real-time system. Say N if you are unsure.
101 Can we use information of configuration file?
104 bool "High memory support"
108 menu "Platform options"
111 prompt "Xtensa System Type"
112 default XTENSA_PLATFORM_ISS
114 config XTENSA_PLATFORM_ISS
117 ISS is an acronym for Tensilica's Instruction Set Simulator.
119 config XTENSA_PLATFORM_XT2000
122 XT2000 is the name of Tensilica's feature-rich emulation platform.
123 This hardware is capable of running a full Linux distribution.
128 config XTENSA_CALIBRATE_CCOUNT
129 bool "Auto calibration of the CPU clock rate"
131 On some platforms (XT2000, for example), the CPU clock rate can
132 vary. The frequency can be determined, however, by measuring
133 against a well known, fixed frequency, such as an UART oscillator.
135 config XTENSA_CPU_CLOCK
136 int "CPU clock rate [MHz]"
137 depends on !XTENSA_CALIBRATE_CCOUNT
140 config GENERIC_CALIBRATE_DELAY
141 bool "Auto calibration of the BogoMIPS value"
143 The BogoMIPS value can easily be derived from the CPU frequency.
146 bool "Default bootloader kernel arguments"
149 string "Initial kernel command string"
150 depends on CMDLINE_BOOL
151 default "console=ttyS0,38400 root=/dev/ram"
153 On some architectures (EBSA110 and CATS), there is currently no way
154 for the boot loader to pass arguments to the kernel. For these
155 architectures, you should supply some command-line options at build
156 time by entering them here. As a minimum, you should specify the
157 memory size and the root device (e.g., mem=64M root=/dev/nfs).
159 config SERIAL_CONSOLE
161 depends on XTENSA_PLATFORM_ISS
164 config XTENSA_ISS_NETWORK
166 depends on XTENSA_PLATFORM_ISS
176 bool "PCI support" if !XTENSA_PLATFORM_ISS
177 depends on !XTENSA_PLATFORM_ISS
180 Find out whether you have a PCI motherboard. PCI is the name of a
181 bus system, i.e. the way the CPU talks to the other stuff inside
182 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
183 VESA. If you have PCI, say Y, otherwise N.
185 The PCI-HOWTO, available from
186 <http://www.linuxdoc.org/docs.html#howto>, contains valuable
187 information about which PCI hardware does work under Linux and which
190 source "drivers/pci/Kconfig"
194 bool "Support for hot-pluggable devices"
196 Say Y here if you want to plug devices into your computer while
197 the system is running, and be able to use them quickly. In many
198 cases, the devices can likewise be unplugged at any time too.
200 One well known example of this is PCMCIA- or PC-cards, credit-card
201 size devices such as network cards, modems or hard drives which are
202 plugged into slots found on all modern laptop computers. Another
203 example, used on modern desktops as well as laptops, is USB.
205 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
206 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
207 Then your kernel will automatically call out to a user mode "policy
208 agent" (/sbin/hotplug) to load modules and set up software needed
209 to use devices as you hotplug them.
211 source "drivers/pcmcia/Kconfig"
213 source "drivers/pci/hotplug/Kconfig"
217 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"