The SuperH is a RISC processor targeted for use in embedded systems and consumer electronics; it was also used in the Sega Dreamcast gaming console. The SuperH port has a home page at <http://www.linux-sh.org/>.
Select MX-G if running on an R8A03022BG part.
Select SH7706 if you have a 133 Mhz SH-3 HD6417706 CPU.
Select SH7707 if you have a 60 Mhz SH-3 HD6417707 CPU.
Select SH7708 if you have a 60 Mhz SH-3 HD6417708S or if you have a 100 Mhz SH-3 HD6417708R CPU.
Select SH7709 if you have a 80 Mhz SH-3 HD6417709 CPU.
Select SH7710 if you have a SH3-DSP SH7710 CPU.
Select SH7712 if you have a SH3-DSP SH7712 CPU.
Select SH7720 if you have a SH3-DSP SH7720 CPU.
Select SH7721 if you have a SH3-DSP SH7721 CPU.
Select SH7750 if you have a 200 Mhz SH-4 HD6417750 CPU.
Select SH7091 if you have an SH-4 based Sega device (such as the Dreamcast, Naomi, and Naomi 2).
Select SH7751 if you have a 166 Mhz SH-4 HD6417751 CPU, or if you have a HD6417751R CPU.
Select SH7723 if you have an SH-MobileR2 CPU.
Select SH7724 if you have an SH-MobileR2R CPU.
Select SH7757 if you have a SH4A SH7757 CPU.
Select SH7763 if you have a SH4A SH7763(R5S77631) CPU.
This enables the build of the TMU timer driver.
This enables build of the CMT timer driver.
This enables build of the MTU2 timer driver.
This option is used to specify the peripheral clock frequency. This is necessary for determining the reference clock value on platforms lacking an RTC.
This adds the cpufreq driver for SuperH. Any CPU that supports clock rate rounding through the clock framework can use this driver. While it will make the kernel slightly larger, this is harmless for CPUs that don't support rate rounding. The driver will also generate a notice in the boot log before disabling itself if the CPU in question is not capable of rate rounding. For details, take a look at <file:Documentation/cpu-freq>. If unsure, say N.
kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot but it is independent of the system firmware. And like a reboot you can start any kernel with it, not just Linux. The name comes from the similarity to the exec system call. It is an ongoing process to be certain the hardware in a machine is properly shutdown, so do not be surprised if this code does not initially work for you. It may help to enable device hotplugging support. As of this writing the exact hardware interface is strongly in flux, so no good recommendation can be made.
Generate crash dump after being started by kexec. This should be normally only set in special crash dump kernels which are loaded in the main kernel with kexec-tools into a specially reserved region and then later executed after a crash by kdump/kexec. The crash dump kernel must be compiled to a memory address not used by the main kernel using MEMORY_START. For more details see Documentation/kdump/kdump.txt
Jump between original kernel and kexeced kernel and invoke code via KEXEC
This kernel feature is useful for number crunching applications that may need to compute untrusted bytecode during their execution. By using pipes or other transports made available to the process as file descriptors supporting the read/write syscalls, it's possible to isolate those applications in their own address space using seccomp. Once seccomp is enabled via prctl, it cannot be disabled and the task is only allowed to execute a few safe syscalls defined by each seccomp mode. If unsure, say N.
This enables support for systems with more than one CPU. If you have a system with only one CPU, like most personal computers, say N. If you have a system with more than one CPU, say Y. If you say N here, the kernel will run on single and multiprocessor machines, but will use only one CPU of a multiprocessor machine. If you say Y here, the kernel will run on many, but not all, singleprocessor machines. On a singleprocessor machine, the kernel will run faster if you say N here. People using multiprocessor machines who say Y here should also say Y to "Enhanced Real Time Clock Support", below. See also <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at <http://www.tldp.org/docs.html#howto>. If you don't know what to do here, say N.
This allows you to specify the maximum number of CPUs which this kernel will support. The maximum supported value is 32 and the minimum value which makes sense is 2. This is purely to save memory - each supported CPU adds approximately eight kilobytes to the kernel image.
Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu.
This enables support for gUSA (general UserSpace Atomicity). This is the default implementation for both UP and non-ll/sc CPUs, and is used by the libc, amongst others. For additional information, design information can be found in <http://lc.linux.or.jp/lc2002/papers/niibe0919p.pdf>. This should only be disabled for special cases where alternate atomicity implementations exist.
Enabling this option will allow the kernel to implement some atomic operations using a software implementation of load-locked/ store-conditional (LLSC). On machines which do not have hardware LLSC, this should be more efficient than the other alternative of disabling interrupts around the atomic sequence.
Enable hardware performance counter support for perf events. If disabled, perf events will use software events only.
This sets the default offset of zero page.
This option allows you to set the link address offset of the zImage. This can be useful if you are on a board which has a small amount of memory.
Say Y here to include experimental MMCIF loading code in romImage. With this enabled it is possible to write the romImage kernel image to an MMC card and boot the kernel straight from the reset vector. At reset the processor Mask ROM will load the first part of the romImage which in turn loads the rest the kernel image to RAM using the MMCIF hardware block.
Setting this option allows the kernel command line arguments to be set.
Given string will overwrite any arguments passed in by a bootloader.
Given string will be concatenated with arguments passed in by a bootloader.
The Maple Bus is SEGA's serial communication bus for peripherals on the Dreamcast. Without this bus support you won't be able to get your Dreamcast keyboard etc to work, so most users probably want to say 'Y' here, unless you are only using the Dreamcast with a serial line terminal or a remote network connection.
Find out whether you have a PCI motherboard. PCI is the name of a bus system, i.e. the way the CPU talks to the other stuff inside your box. If you have PCI, say Y, otherwise N.
Say Y here to get to see options for using your Linux host to run other operating systems inside virtual machines (guests). This option alone does not add any kernel code. If you say N, all options in this submenu will be skipped and disabled.