| 1 | # SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | config 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 | |
| 16 | config 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 | |
| 25 | config EARLY_PRINTK |
| 26 | bool "Early printk" |
| 27 | depends on SH_STANDARD_BIOS |
| 28 | help |
| 29 | Say Y here to redirect kernel printk messages to the serial port |
| 30 | used by the SH-IPL bootloader, starting very early in the boot |
| 31 | process and ending when the kernel's serial console is initialised. |
| 32 | This option is only useful while porting the kernel to a new machine, |
| 33 | when the kernel may crash or hang before the serial console is |
| 34 | initialised. If unsure, say N. |
| 35 | |
| 36 | config 4KSTACKS |
| 37 | bool "Use 4Kb for kernel stacks instead of 8Kb" |
| 38 | depends on DEBUG_KERNEL && (MMU || BROKEN) && !PAGE_SIZE_64KB |
| 39 | help |
| 40 | If you say Y here the kernel will use a 4Kb stacksize for the |
| 41 | kernel stack attached to each process/thread. This facilitates |
| 42 | running more threads on a system and also reduces the pressure |
| 43 | on the VM subsystem for higher order allocations. This option |
| 44 | will also use IRQ stacks to compensate for the reduced stackspace. |
| 45 | |
| 46 | config IRQSTACKS |
| 47 | bool "Use separate kernel stacks when processing interrupts" |
| 48 | depends on DEBUG_KERNEL && BROKEN |
| 49 | help |
| 50 | If you say Y here the kernel will use separate kernel stacks |
| 51 | for handling hard and soft interrupts. This can help avoid |
| 52 | overflowing the process kernel stacks. |
| 53 | |
| 54 | config DUMP_CODE |
| 55 | bool "Show disassembly of nearby code in register dumps" |
| 56 | depends on DEBUG_KERNEL |
| 57 | default y if DEBUG_BUGVERBOSE |
| 58 | default n |
| 59 | help |
| 60 | This prints out a code trace of the instructions leading up to |
| 61 | the faulting instruction as a debugging aid. As this does grow |
| 62 | the kernel in size a bit, most users will want to say N here. |
| 63 | |
| 64 | Those looking for more verbose debugging output should say Y. |
| 65 | |
| 66 | config DWARF_UNWINDER |
| 67 | bool "Enable the DWARF unwinder for stacktraces" |
| 68 | depends on DEBUG_KERNEL |
| 69 | select FRAME_POINTER |
| 70 | default n |
| 71 | help |
| 72 | Enabling this option will make stacktraces more accurate, at |
| 73 | the cost of an increase in overall kernel size. |
| 74 | |
| 75 | config SH_NO_BSS_INIT |
| 76 | bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)" |
| 77 | depends on DEBUG_KERNEL |
| 78 | default n |
| 79 | help |
| 80 | If running in painfully slow environments, such as an RTL |
| 81 | simulation or from remote memory via SHdebug, where the memory |
| 82 | can already be guaranteed to ber zeroed on boot, say Y. |
| 83 | |
| 84 | For all other cases, say N. If this option seems perplexing, or |
| 85 | you aren't sure, say N. |
| 86 | |
| 87 | config MCOUNT |
| 88 | def_bool y |
| 89 | depends on STACK_DEBUG || FUNCTION_TRACER |