1# SPDX-License-Identifier: GPL-2.0 2 3config SH_STANDARD_BIOS 4 bool "Use LinuxSH standard BIOS" 5 help 6 Say Y here if your target has the gdb-sh-stub 7 package from www.m17n.org (or any conforming standard LinuxSH BIOS) 8 in FLASH or EPROM. The kernel will use standard BIOS calls during 9 boot for various housekeeping tasks (including calls to read and 10 write characters to a system console, get a MAC address from an 11 on-board Ethernet interface, and shut down the hardware). Note this 12 does not work with machines with an existing operating system in 13 mask ROM and no flash (WindowsCE machines fall in this category). 14 If unsure, say N. 15 16config STACK_DEBUG 17 bool "Check for stack overflows" 18 depends on DEBUG_KERNEL && PRINTK 19 help 20 This option will cause messages to be printed if free stack space 21 drops below a certain limit. Saying Y here will add overhead to 22 every function call and will therefore incur a major 23 performance hit. Most users should say N. 24 25config 4KSTACKS 26 bool "Use 4Kb for kernel stacks instead of 8Kb" 27 depends on DEBUG_KERNEL && (MMU || BROKEN) && !PAGE_SIZE_64KB 28 help 29 If you say Y here the kernel will use a 4Kb stacksize for the 30 kernel stack attached to each process/thread. This facilitates 31 running more threads on a system and also reduces the pressure 32 on the VM subsystem for higher order allocations. This option 33 will also use IRQ stacks to compensate for the reduced stackspace. 34 35config IRQSTACKS 36 bool "Use separate kernel stacks when processing interrupts" 37 depends on DEBUG_KERNEL && BROKEN 38 help 39 If you say Y here the kernel will use separate kernel stacks 40 for handling hard and soft interrupts. This can help avoid 41 overflowing the process kernel stacks. 42 43config DUMP_CODE 44 bool "Show disassembly of nearby code in register dumps" 45 depends on DEBUG_KERNEL 46 default y if DEBUG_BUGVERBOSE 47 default n 48 help 49 This prints out a code trace of the instructions leading up to 50 the faulting instruction as a debugging aid. As this does grow 51 the kernel in size a bit, most users will want to say N here. 52 53 Those looking for more verbose debugging output should say Y. 54 55config DWARF_UNWINDER 56 bool "Enable the DWARF unwinder for stacktraces" 57 depends on DEBUG_KERNEL 58 select FRAME_POINTER 59 default n 60 help 61 Enabling this option will make stacktraces more accurate, at 62 the cost of an increase in overall kernel size. 63 64config SH_NO_BSS_INIT 65 bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)" 66 depends on DEBUG_KERNEL 67 default n 68 help 69 If running in painfully slow environments, such as an RTL 70 simulation or from remote memory via SHdebug, where the memory 71 can already be guaranteed to ber zeroed on boot, say Y. 72 73 For all other cases, say N. If this option seems perplexing, or 74 you aren't sure, say N. 75 76config MCOUNT 77 def_bool y 78 depends on STACK_DEBUG || FUNCTION_TRACER 79