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/>.
25 config RWSEM_XCHGADD_ALGORITHM
29 config GENERIC_HARDIRQS
35 menu "Processor type and features"
38 prompt "Xtensa Processor Configuration"
39 default XTENSA_CPU_LINUX_BE
41 config XTENSA_CPU_LINUX_BE
44 The linux_be processor configuration is the baseline Xtensa
45 configurations included in this kernel and also used by
46 binutils, gcc, and gdb. It contains no TIE, no coprocessors,
47 and the following configuration options:
49 Code Density Option 2 Misc Special Registers
50 NSA/NSAU Instructions 128-bit Data Bus Width
51 Processor ID 8K, 2-way I and D Caches
52 Zero-Overhead Loops 2 Inst Address Break Registers
53 Big Endian 2 Data Address Break Registers
54 64 General-Purpose Registers JTAG Interface and Trace Port
55 17 Interrupts MMU w/ TLBs and Autorefill
56 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs)
57 3 Timers Unaligned Exceptions
64 config XTENSA_UNALIGNED_USER
65 bool "Unaligned memory access in use space"
67 The Xtensa architecture currently does not handle unaligned
68 memory accesses in hardware but through an exception handler.
69 Per default, unaligned memory accesses are disabled in user space.
71 Say Y here to enable unaligned memory access in user space.
74 bool "Preemptible Kernel"
76 This option reduces the latency of the kernel when reacting to
77 real-time or interactive events by allowing a low priority process to
78 be preempted even if it is in kernel mode executing a system call.
79 Unfortunately the kernel code has some race conditions if both
80 CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
81 currently disabled if you are building an SMP kernel.
83 Say Y here if you are building a kernel for a desktop, embedded
84 or real-time system. Say N if you are unsure.
89 Can we use information of configuration file?
92 bool "High memory support"
96 menu "Platform options"
99 prompt "Xtensa System Type"
100 default XTENSA_PLATFORM_ISS
102 config XTENSA_PLATFORM_ISS
105 ISS is an acronym for Tensilica's Instruction Set Simulator.
107 config XTENSA_PLATFORM_XT2000
110 XT2000 is the name of Tensilica's feature-rich emulation platform.
111 This hardware is capable of running a full Linux distribution.
116 config XTENSA_CALIBRATE_CCOUNT
117 bool "Auto calibration of the CPU clock rate"
119 On some platforms (XT2000, for example), the CPU clock rate can
120 vary. The frequency can be determined, however, by measuring
121 against a well known, fixed frequency, such as an UART oscillator.
123 config XTENSA_CPU_CLOCK
124 int "CPU clock rate [MHz]"
125 depends on !XTENSA_CALIBRATE_CCOUNT
128 config GENERIC_CALIBRATE_DELAY
129 bool "Auto calibration of the BogoMIPS value"
131 The BogoMIPS value can easily be derived from the CPU frequency.
134 bool "Default bootloader kernel arguments"
137 string "Initial kernel command string"
138 depends on CMDLINE_BOOL
139 default "console=ttyS0,38400 root=/dev/ram"
141 On some architectures (EBSA110 and CATS), there is currently no way
142 for the boot loader to pass arguments to the kernel. For these
143 architectures, you should supply some command-line options at build
144 time by entering them here. As a minimum, you should specify the
145 memory size and the root device (e.g., mem=64M root=/dev/nfs).
147 config SERIAL_CONSOLE
149 depends on XTENSA_PLATFORM_ISS
152 config XTENSA_ISS_NETWORK
154 depends on XTENSA_PLATFORM_ISS
164 bool "PCI support" if !XTENSA_PLATFORM_ISS
165 depends on !XTENSA_PLATFORM_ISS
168 Find out whether you have a PCI motherboard. PCI is the name of a
169 bus system, i.e. the way the CPU talks to the other stuff inside
170 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
171 VESA. If you have PCI, say Y, otherwise N.
173 The PCI-HOWTO, available from
174 <http://www.linuxdoc.org/docs.html#howto>, contains valuable
175 information about which PCI hardware does work under Linux and which
178 source "drivers/pci/Kconfig"
182 bool "Support for hot-pluggable devices"
184 Say Y here if you want to plug devices into your computer while
185 the system is running, and be able to use them quickly. In many
186 cases, the devices can likewise be unplugged at any time too.
188 One well known example of this is PCMCIA- or PC-cards, credit-card
189 size devices such as network cards, modems or hard drives which are
190 plugged into slots found on all modern laptop computers. Another
191 example, used on modern desktops as well as laptops, is USB.
193 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
194 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
195 Then your kernel will automatically call out to a user mode "policy
196 agent" (/sbin/hotplug) to load modules and set up software needed
197 to use devices as you hotplug them.
199 source "drivers/pcmcia/Kconfig"
201 source "drivers/pci/hotplug/Kconfig"
205 menu "Exectuable file formats"
213 If you enabled support for /proc file system then the file
214 /proc/kcore will contain the kernel core image in ELF format. This
217 $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
219 This is especially useful if you have compiled the kernel with the
220 "-g" option to preserve debugging information. It is mainly used
221 for examining kernel data structures on the live kernel.
223 source "fs/Kconfig.binfmt"
229 source "drivers/Kconfig"
233 menu "Xtensa initrd options"
234 depends on BLK_DEV_INITRD
236 config EMBEDDED_RAMDISK
237 bool "Embed root filesystem ramdisk into the kernel"
239 config EMBEDDED_RAMDISK_IMAGE
240 string "Filename of gziped ramdisk image"
241 depends on EMBEDDED_RAMDISK
244 This is the filename of the ramdisk image to be built into the
245 kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/.
246 The ramdisk image is not part of the kernel distribution; you must
247 provide one yourself.
250 source "arch/xtensa/Kconfig.debug"
252 source "security/Kconfig"
254 source "crypto/Kconfig"