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