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 SH7734 if you have a SH4A SH7734 CPU.
Select SH7757 if you have a SH4A SH7757 CPU.
Select SH7763 if you have a SH4A SH7763(R5S77631) CPU.
This option is used to specify the peripheral clock frequency. This is necessary for determining the reference clock value on platforms lacking an RTC.
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. 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 PHYSICAL_START. For more details see Documentation/admin-guide/kdump/kdump.rst
Jump between original kernel and kexeced kernel and invoke code via KEXEC
This gives the physical address where the kernel is loaded and is ordinarily the same as MEMORY_START. Different values are primarily used in the case of kexec on panic where the fail safe kernel needs to run at a different address than the panic-ed kernel.
This enables support for systems with more than one CPU. If you have a system with only one CPU, say N. If you have a system with more than one CPU, say Y. If you say N here, the kernel will run on uni- 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, uniprocessor machines. On a uniprocessor 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/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at <https://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.
Link a device tree blob for particular hardware into the kernel, suppressing use of the DTB pointer provided by the bootloader. This option should only be used with legacy bootloaders that are not capable of providing a DTB to the kernel, or for experimental hardware without stable device tree bindings.
Base name (without suffix, relative to arch/sh/boot/dts) for the a DTS file that will be used to produce the DTB linked into the kernel.
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.