1menu "Kernel hacking" 2 3source "lib/Kconfig.debug" 4 5config STRICT_DEVMEM 6 bool "Filter access to /dev/mem" 7 depends on MMU 8 ---help--- 9 If this option is disabled, you allow userspace (root) access to all 10 of memory, including kernel and userspace memory. Accidental 11 access to this is obviously disastrous, but specific access can 12 be used by people debugging the kernel. 13 14 If this option is switched on, the /dev/mem file only allows 15 userspace access to memory mapped peripherals. 16 17 If in doubt, say Y. 18 19# RMK wants arm kernels compiled with frame pointers or stack unwinding. 20# If you know what you are doing and are willing to live without stack 21# traces, you can get a slightly smaller kernel by setting this option to 22# n, but then RMK will have to kill you ;). 23config FRAME_POINTER 24 bool 25 depends on !THUMB2_KERNEL 26 default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER 27 help 28 If you say N here, the resulting kernel will be slightly smaller and 29 faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled, 30 when a problem occurs with the kernel, the information that is 31 reported is severely limited. 32 33config ARM_UNWIND 34 bool "Enable stack unwinding support (EXPERIMENTAL)" 35 depends on AEABI && EXPERIMENTAL 36 default y 37 help 38 This option enables stack unwinding support in the kernel 39 using the information automatically generated by the 40 compiler. The resulting kernel image is slightly bigger but 41 the performance is not affected. Currently, this feature 42 only works with EABI compilers. If unsure say Y. 43 44config OLD_MCOUNT 45 bool 46 depends on FUNCTION_TRACER && FRAME_POINTER 47 default y 48 49config DEBUG_USER 50 bool "Verbose user fault messages" 51 help 52 When a user program crashes due to an exception, the kernel can 53 print a brief message explaining what the problem was. This is 54 sometimes helpful for debugging but serves no purpose on a 55 production system. Most people should say N here. 56 57 In addition, you need to pass user_debug=N on the kernel command 58 line to enable this feature. N consists of the sum of: 59 60 1 - undefined instruction events 61 2 - system calls 62 4 - invalid data aborts 63 8 - SIGSEGV faults 64 16 - SIGBUS faults 65 66# These options are only for real kernel hackers who want to get their hands dirty. 67config DEBUG_LL 68 bool "Kernel low-level debugging functions" 69 depends on DEBUG_KERNEL 70 help 71 Say Y here to include definitions of printascii, printch, printhex 72 in the kernel. This is helpful if you are debugging code that 73 executes before the console is initialized. 74 75config EARLY_PRINTK 76 bool "Early printk" 77 depends on DEBUG_LL 78 help 79 Say Y here if you want to have an early console using the 80 kernel low-level debugging functions. Add earlyprintk to your 81 kernel parameters to enable this console. 82 83config DEBUG_ICEDCC 84 bool "Kernel low-level debugging via EmbeddedICE DCC channel" 85 depends on DEBUG_LL 86 help 87 Say Y here if you want the debug print routines to direct their 88 output to the EmbeddedICE macrocell's DCC channel using 89 co-processor 14. This is known to work on the ARM9 style ICE 90 channel and on the XScale with the PEEDI. 91 92 It does include a timeout to ensure that the system does not 93 totally freeze when there is nothing connected to read. 94 95config OC_ETM 96 bool "On-chip ETM and ETB" 97 select ARM_AMBA 98 help 99 Enables the on-chip embedded trace macrocell and embedded trace 100 buffer driver that will allow you to collect traces of the 101 kernel code. 102 103config DEBUG_DC21285_PORT 104 bool "Kernel low-level debugging messages via footbridge serial port" 105 depends on DEBUG_LL && FOOTBRIDGE 106 help 107 Say Y here if you want the debug print routines to direct their 108 output to the serial port in the DC21285 (Footbridge). Saying N 109 will cause the debug messages to appear on the first 16550 110 serial port. 111 112config DEBUG_CLPS711X_UART2 113 bool "Kernel low-level debugging messages via UART2" 114 depends on DEBUG_LL && ARCH_CLPS711X 115 help 116 Say Y here if you want the debug print routines to direct their 117 output to the second serial port on these devices. Saying N will 118 cause the debug messages to appear on the first serial port. 119 120config DEBUG_S3C_UART 121 depends on PLAT_SAMSUNG 122 int "S3C UART to use for low-level debug" 123 default "0" 124 help 125 Choice for UART for kernel low-level using S3C UARTS, 126 should be between zero and two. The port must have been 127 initialised by the boot-loader before use. 128 129 The uncompressor code port configuration is now handled 130 by CONFIG_S3C_LOWLEVEL_UART_PORT. 131 132endmenu 133