1# SPDX-License-Identifier: GPL-2.0 2 3config TRACE_IRQFLAGS_SUPPORT 4 def_bool y 5 6config SH_STANDARD_BIOS 7 bool "Use LinuxSH standard BIOS" 8 help 9 Say Y here if your target has the gdb-sh-stub 10 package from www.m17n.org (or any conforming standard LinuxSH BIOS) 11 in FLASH or EPROM. The kernel will use standard BIOS calls during 12 boot for various housekeeping tasks (including calls to read and 13 write characters to a system console, get a MAC address from an 14 on-board Ethernet interface, and shut down the hardware). Note this 15 does not work with machines with an existing operating system in 16 mask ROM and no flash (WindowsCE machines fall in this category). 17 If unsure, say N. 18 19config STACK_DEBUG 20 bool "Check for stack overflows" 21 depends on DEBUG_KERNEL && PRINTK 22 help 23 This option will cause messages to be printed if free stack space 24 drops below a certain limit. Saying Y here will add overhead to 25 every function call and will therefore incur a major 26 performance hit. Most users should say N. 27 28config EARLY_PRINTK 29 bool "Early printk" 30 depends on SH_STANDARD_BIOS 31 help 32 Say Y here to redirect kernel printk messages to the serial port 33 used by the SH-IPL bootloader, starting very early in the boot 34 process and ending when the kernel's serial console is initialised. 35 This option is only useful while porting the kernel to a new machine, 36 when the kernel may crash or hang before the serial console is 37 initialised. If unsure, say N. 38 39config 4KSTACKS 40 bool "Use 4Kb for kernel stacks instead of 8Kb" 41 depends on DEBUG_KERNEL && (MMU || BROKEN) && !PAGE_SIZE_64KB 42 help 43 If you say Y here the kernel will use a 4Kb stacksize for the 44 kernel stack attached to each process/thread. This facilitates 45 running more threads on a system and also reduces the pressure 46 on the VM subsystem for higher order allocations. This option 47 will also use IRQ stacks to compensate for the reduced stackspace. 48 49config IRQSTACKS 50 bool "Use separate kernel stacks when processing interrupts" 51 depends on DEBUG_KERNEL && BROKEN 52 help 53 If you say Y here the kernel will use separate kernel stacks 54 for handling hard and soft interrupts. This can help avoid 55 overflowing the process kernel stacks. 56 57config DUMP_CODE 58 bool "Show disassembly of nearby code in register dumps" 59 depends on DEBUG_KERNEL 60 default y if DEBUG_BUGVERBOSE 61 default n 62 help 63 This prints out a code trace of the instructions leading up to 64 the faulting instruction as a debugging aid. As this does grow 65 the kernel in size a bit, most users will want to say N here. 66 67 Those looking for more verbose debugging output should say Y. 68 69config DWARF_UNWINDER 70 bool "Enable the DWARF unwinder for stacktraces" 71 depends on DEBUG_KERNEL 72 select FRAME_POINTER 73 default n 74 help 75 Enabling this option will make stacktraces more accurate, at 76 the cost of an increase in overall kernel size. 77 78config SH_NO_BSS_INIT 79 bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)" 80 depends on DEBUG_KERNEL 81 default n 82 help 83 If running in painfully slow environments, such as an RTL 84 simulation or from remote memory via SHdebug, where the memory 85 can already be guaranteed to ber zeroed on boot, say Y. 86 87 For all other cases, say N. If this option seems perplexing, or 88 you aren't sure, say N. 89 90config MCOUNT 91 def_bool y 92 depends on STACK_DEBUG || FUNCTION_TRACER 93