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_VARIANT_FSF
53 config XTENSA_VARIANT_FSF
61 config XTENSA_UNALIGNED_USER
62 bool "Unaligned memory access in use space"
64 The Xtensa architecture currently does not handle unaligned
65 memory accesses in hardware but through an exception handler.
66 Per default, unaligned memory accesses are disabled in user space.
68 Say Y here to enable unaligned memory access in user space.
71 bool "Preemptible Kernel"
73 This option reduces the latency of the kernel when reacting to
74 real-time or interactive events by allowing a low priority process to
75 be preempted even if it is in kernel mode executing a system call.
76 Unfortunately the kernel code has some race conditions if both
77 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
78 currently disabled if you are building an SMP kernel.
80 Say Y here if you are building a kernel for a desktop, embedded
81 or real-time system. Say N if you are unsure.
86 Can we use information of configuration file?
89 bool "High memory support"
93 menu "Platform options"
96 prompt "Xtensa System Type"
97 default XTENSA_PLATFORM_ISS
99 config XTENSA_PLATFORM_ISS
102 ISS is an acronym for Tensilica's Instruction Set Simulator.
104 config XTENSA_PLATFORM_XT2000
107 XT2000 is the name of Tensilica's feature-rich emulation platform.
108 This hardware is capable of running a full Linux distribution.
113 config XTENSA_CALIBRATE_CCOUNT
114 bool "Auto calibration of the CPU clock rate"
116 On some platforms (XT2000, for example), the CPU clock rate can
117 vary. The frequency can be determined, however, by measuring
118 against a well known, fixed frequency, such as an UART oscillator.
120 config XTENSA_CPU_CLOCK
121 int "CPU clock rate [MHz]"
122 depends on !XTENSA_CALIBRATE_CCOUNT
125 config GENERIC_CALIBRATE_DELAY
126 bool "Auto calibration of the BogoMIPS value"
128 The BogoMIPS value can easily be derived from the CPU frequency.
131 bool "Default bootloader kernel arguments"
134 string "Initial kernel command string"
135 depends on CMDLINE_BOOL
136 default "console=ttyS0,38400 root=/dev/ram"
138 On some architectures (EBSA110 and CATS), there is currently no way
139 for the boot loader to pass arguments to the kernel. For these
140 architectures, you should supply some command-line options at build
141 time by entering them here. As a minimum, you should specify the
142 memory size and the root device (e.g., mem=64M root=/dev/nfs).
144 config SERIAL_CONSOLE
146 depends on XTENSA_PLATFORM_ISS
149 config XTENSA_ISS_NETWORK
151 depends on XTENSA_PLATFORM_ISS
161 bool "PCI support" if !XTENSA_PLATFORM_ISS
162 depends on !XTENSA_PLATFORM_ISS
165 Find out whether you have a PCI motherboard. PCI is the name of a
166 bus system, i.e. the way the CPU talks to the other stuff inside
167 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
168 VESA. If you have PCI, say Y, otherwise N.
170 The PCI-HOWTO, available from
171 <http://www.linuxdoc.org/docs.html#howto>, contains valuable
172 information about which PCI hardware does work under Linux and which
175 source "drivers/pci/Kconfig"
179 bool "Support for hot-pluggable devices"
181 Say Y here if you want to plug devices into your computer while
182 the system is running, and be able to use them quickly. In many
183 cases, the devices can likewise be unplugged at any time too.
185 One well known example of this is PCMCIA- or PC-cards, credit-card
186 size devices such as network cards, modems or hard drives which are
187 plugged into slots found on all modern laptop computers. Another
188 example, used on modern desktops as well as laptops, is USB.
190 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
191 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
192 Then your kernel will automatically call out to a user mode "policy
193 agent" (/sbin/hotplug) to load modules and set up software needed
194 to use devices as you hotplug them.
196 source "drivers/pcmcia/Kconfig"
198 source "drivers/pci/hotplug/Kconfig"
202 menu "Executable file formats"
210 If you enabled support for /proc file system then the file
211 /proc/kcore will contain the kernel core image in ELF format. This
214 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
216 This is especially useful if you have compiled the kernel with the
217 "-g" option to preserve debugging information. It is mainly used
218 for examining kernel data structures on the live kernel.
220 source "fs/Kconfig.binfmt"
226 source "drivers/Kconfig"
230 menu "Xtensa initrd options"
231 depends on BLK_DEV_INITRD
233 config EMBEDDED_RAMDISK
234 bool "Embed root filesystem ramdisk into the kernel"
236 config EMBEDDED_RAMDISK_IMAGE
237 string "Filename of gzipped ramdisk image"
238 depends on EMBEDDED_RAMDISK
241 This is the filename of the ramdisk image to be built into the
242 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
243 The ramdisk image is not part of the kernel distribution; you must
244 provide one yourself.
247 source "arch/xtensa/Kconfig.debug"
249 source "security/Kconfig"
251 source "crypto/Kconfig"