1 # For a description of the syntax of this configuration file,
2 # see Documentation/kbuild/config-language.txt.
4 mainmenu "Linux/Xtensa Kernel Configuration"
18 Xtensa processors are 32-bit RISC machines designed by Tensilica
19 primarily for embedded systems. These processors are both
20 configurable and extensible. The Linux port to the Xtensa
21 architecture supports all processor configurations and extensions,
22 with reasonable minimum requirements. The Xtensa Linux project has
23 a home page at <http://xtensa.sourceforge.net/>.
25 config RWSEM_XCHGADD_ALGORITHM
29 config GENERIC_FIND_NEXT_BIT
33 config GENERIC_HWEIGHT
37 config GENERIC_HARDIRQS
41 config ARCH_HAS_ILOG2_U32
45 config ARCH_HAS_ILOG2_U64
51 menu "Processor type and features"
54 prompt "Xtensa Processor Configuration"
55 default XTENSA_VARIANT_FSF
57 config XTENSA_VARIANT_FSF
65 config XTENSA_UNALIGNED_USER
66 bool "Unaligned memory access in use space"
68 The Xtensa architecture currently does not handle unaligned
69 memory accesses in hardware but through an exception handler.
70 Per default, unaligned memory accesses are disabled in user space.
72 Say Y here to enable unaligned memory access in user space.
75 bool "Preemptible Kernel"
77 This option reduces the latency of the kernel when reacting to
78 real-time or interactive events by allowing a low priority process to
79 be preempted even if it is in kernel mode executing a system call.
80 Unfortunately the kernel code has some race conditions if both
81 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
82 currently disabled if you are building an SMP kernel.
84 Say Y here if you are building a kernel for a desktop, embedded
85 or real-time system. Say N if you are unsure.
90 Can we use information of configuration file?
93 bool "High memory support"
97 menu "Platform options"
100 prompt "Xtensa System Type"
101 default XTENSA_PLATFORM_ISS
103 config XTENSA_PLATFORM_ISS
106 ISS is an acronym for Tensilica's Instruction Set Simulator.
108 config XTENSA_PLATFORM_XT2000
111 XT2000 is the name of Tensilica's feature-rich emulation platform.
112 This hardware is capable of running a full Linux distribution.
117 config XTENSA_CALIBRATE_CCOUNT
118 bool "Auto calibration of the CPU clock rate"
120 On some platforms (XT2000, for example), the CPU clock rate can
121 vary. The frequency can be determined, however, by measuring
122 against a well known, fixed frequency, such as an UART oscillator.
124 config XTENSA_CPU_CLOCK
125 int "CPU clock rate [MHz]"
126 depends on !XTENSA_CALIBRATE_CCOUNT
129 config GENERIC_CALIBRATE_DELAY
130 bool "Auto calibration of the BogoMIPS value"
132 The BogoMIPS value can easily be derived from the CPU frequency.
135 bool "Default bootloader kernel arguments"
138 string "Initial kernel command string"
139 depends on CMDLINE_BOOL
140 default "console=ttyS0,38400 root=/dev/ram"
142 On some architectures (EBSA110 and CATS), there is currently no way
143 for the boot loader to pass arguments to the kernel. For these
144 architectures, you should supply some command-line options at build
145 time by entering them here. As a minimum, you should specify the
146 memory size and the root device (e.g., mem=64M root=/dev/nfs).
148 config SERIAL_CONSOLE
150 depends on XTENSA_PLATFORM_ISS
153 config XTENSA_ISS_NETWORK
155 depends on XTENSA_PLATFORM_ISS
165 bool "PCI support" if !XTENSA_PLATFORM_ISS
166 depends on !XTENSA_PLATFORM_ISS
169 Find out whether you have a PCI motherboard. PCI is the name of a
170 bus system, i.e. the way the CPU talks to the other stuff inside
171 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
172 VESA. If you have PCI, say Y, otherwise N.
174 The PCI-HOWTO, available from
175 <http://www.linuxdoc.org/docs.html#howto>, contains valuable
176 information about which PCI hardware does work under Linux and which
179 source "drivers/pci/Kconfig"
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 KMOD, and build a modular kernel. Get agent
195 software (at <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"
214 If you enabled support for /proc file system then the file
215 /proc/kcore will contain the kernel core image in ELF format. This
218 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
220 This is especially useful if you have compiled the kernel with the
221 "-g" option to preserve debugging information. It is mainly used
222 for examining kernel data structures on the live kernel.
224 source "fs/Kconfig.binfmt"
230 source "drivers/Kconfig"
234 menu "Xtensa initrd options"
235 depends on BLK_DEV_INITRD
237 config EMBEDDED_RAMDISK
238 bool "Embed root filesystem ramdisk into the kernel"
240 config EMBEDDED_RAMDISK_IMAGE
241 string "Filename of gzipped ramdisk image"
242 depends on EMBEDDED_RAMDISK
245 This is the filename of the ramdisk image to be built into the
246 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
247 The ramdisk image is not part of the kernel distribution; you must
248 provide one yourself.
251 source "arch/xtensa/Kconfig.debug"
253 source "security/Kconfig"
255 source "crypto/Kconfig"