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 RWSEM_GENERIC_SPINLOCK
43 menu "Processor type and features"
46 prompt "Xtensa Processor Configuration"
47 default XTENSA_CPU_LINUX_BE
49 config XTENSA_CPU_LINUX_BE
52 The linux_be processor configuration is the baseline Xtensa
53 configurations included in this kernel and also used by
54 binutils, gcc, and gdb. It contains no TIE, no coprocessors,
55 and the following configuration options:
57 Code Density Option 2 Misc Special Registers
58 NSA/NSAU Instructions 128-bit Data Bus Width
59 Processor ID 8K, 2-way I and D Caches
60 Zero-Overhead Loops 2 Inst Address Break Registers
61 Big Endian 2 Data Address Break Registers
62 64 General-Purpose Registers JTAG Interface and Trace Port
63 17 Interrupts MMU w/ TLBs and Autorefill
64 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs)
65 3 Timers Unaligned Exceptions
72 config XTENSA_UNALIGNED_USER
73 bool "Unaligned memory access in use space"
75 The Xtensa architecture currently does not handle unaligned
76 memory accesses in hardware but through an exception handler.
77 Per default, unaligned memory accesses are disabled in user space.
79 Say Y here to enable unaligned memory access in user space.
82 bool "Preemptible Kernel"
84 This option reduces the latency of the kernel when reacting to
85 real-time or interactive events by allowing a low priority process to
86 be preempted even if it is in kernel mode executing a system call.
87 Unfortunately the kernel code has some race conditions if both
88 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
89 currently disabled if you are building an SMP kernel.
91 Say Y here if you are building a kernel for a desktop, embedded
92 or real-time system. Say N if you are unsure.
97 Can we use information of configuration file?
100 bool "High memory support"
104 menu "Platform options"
107 prompt "Xtensa System Type"
108 default XTENSA_PLATFORM_ISS
110 config XTENSA_PLATFORM_ISS
113 ISS is an acronym for Tensilica's Instruction Set Simulator.
115 config XTENSA_PLATFORM_XT2000
118 XT2000 is the name of Tensilica's feature-rich emulation platform.
119 This hardware is capable of running a full Linux distribution.
124 config XTENSA_CALIBRATE_CCOUNT
125 bool "Auto calibration of the CPU clock rate"
127 On some platforms (XT2000, for example), the CPU clock rate can
128 vary. The frequency can be determined, however, by measuring
129 against a well known, fixed frequency, such as an UART oscillator.
131 config XTENSA_CPU_CLOCK
132 int "CPU clock rate [MHz]"
133 depends on !XTENSA_CALIBRATE_CCOUNT
136 config GENERIC_CALIBRATE_DELAY
137 bool "Auto calibration of the BogoMIPS value"
139 The BogoMIPS value can easily be derived from the CPU frequency.
142 bool "Default bootloader kernel arguments"
145 string "Initial kernel command string"
146 depends on CMDLINE_BOOL
147 default "console=ttyS0,38400 root=/dev/ram"
149 On some architectures (EBSA110 and CATS), there is currently no way
150 for the boot loader to pass arguments to the kernel. For these
151 architectures, you should supply some command-line options at build
152 time by entering them here. As a minimum, you should specify the
153 memory size and the root device (e.g., mem=64M root=/dev/nfs).
155 config SERIAL_CONSOLE
157 depends on XTENSA_PLATFORM_ISS
160 config XTENSA_ISS_NETWORK
162 depends on XTENSA_PLATFORM_ISS
172 bool "PCI support" if !XTENSA_PLATFORM_ISS
173 depends on !XTENSA_PLATFORM_ISS
176 Find out whether you have a PCI motherboard. PCI is the name of a
177 bus system, i.e. the way the CPU talks to the other stuff inside
178 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
179 VESA. If you have PCI, say Y, otherwise N.
181 The PCI-HOWTO, available from
182 <http://www.linuxdoc.org/docs.html#howto>, contains valuable
183 information about which PCI hardware does work under Linux and which
186 source "drivers/pci/Kconfig"
190 bool "Support for hot-pluggable devices"
192 Say Y here if you want to plug devices into your computer while
193 the system is running, and be able to use them quickly. In many
194 cases, the devices can likewise be unplugged at any time too.
196 One well known example of this is PCMCIA- or PC-cards, credit-card
197 size devices such as network cards, modems or hard drives which are
198 plugged into slots found on all modern laptop computers. Another
199 example, used on modern desktops as well as laptops, is USB.
201 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
202 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
203 Then your kernel will automatically call out to a user mode "policy
204 agent" (/sbin/hotplug) to load modules and set up software needed
205 to use devices as you hotplug them.
207 source "drivers/pcmcia/Kconfig"
209 source "drivers/pci/hotplug/Kconfig"
213 menu "Exectuable file formats"
221 If you enabled support for /proc file system then the file
222 /proc/kcore will contain the kernel core image in ELF format. This
225 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
227 This is especially useful if you have compiled the kernel with the
228 "-g" option to preserve debugging information. It is mainly used
229 for examining kernel data structures on the live kernel.
231 source "fs/Kconfig.binfmt"
237 source "drivers/Kconfig"
241 menu "Xtensa initrd options"
242 depends on BLK_DEV_INITRD
244 config EMBEDDED_RAMDISK
245 bool "Embed root filesystem ramdisk into the kernel"
247 config EMBEDDED_RAMDISK_IMAGE
248 string "Filename of gziped ramdisk image"
249 depends on EMBEDDED_RAMDISK
252 This is the filename of the ramdisk image to be built into the
253 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
254 The ramdisk image is not part of the kernel distribution; you must
255 provide one yourself.
258 source "arch/xtensa/Kconfig.debug"
260 source "security/Kconfig"
262 source "crypto/Kconfig"