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