11da177e4SLinus Torvaldsmenu "Kernel hacking" 21da177e4SLinus Torvalds 31da177e4SLinus Torvaldssource "lib/Kconfig.debug" 41da177e4SLinus Torvalds 51da177e4SLinus Torvalds# RMK wants arm kernels compiled with frame pointers so hardwire this to y. 61da177e4SLinus Torvalds# If you know what you are doing and are willing to live without stack 71da177e4SLinus Torvalds# traces, you can get a slightly smaller kernel by setting this option to 81da177e4SLinus Torvalds# n, but then RMK will have to kill you ;). 91da177e4SLinus Torvaldsconfig FRAME_POINTER 101da177e4SLinus Torvalds bool 111da177e4SLinus Torvalds default y 121da177e4SLinus Torvalds help 131da177e4SLinus Torvalds If you say N here, the resulting kernel will be slightly smaller and 141da177e4SLinus Torvalds faster. However, when a problem occurs with the kernel, the 151da177e4SLinus Torvalds information that is reported is severely limited. Most people 161da177e4SLinus Torvalds should say Y here. 171da177e4SLinus Torvalds 181da177e4SLinus Torvaldsconfig DEBUG_USER 191da177e4SLinus Torvalds bool "Verbose user fault messages" 201da177e4SLinus Torvalds help 211da177e4SLinus Torvalds When a user program crashes due to an exception, the kernel can 221da177e4SLinus Torvalds print a brief message explaining what the problem was. This is 231da177e4SLinus Torvalds sometimes helpful for debugging but serves no purpose on a 241da177e4SLinus Torvalds production system. Most people should say N here. 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds In addition, you need to pass user_debug=N on the kernel command 271da177e4SLinus Torvalds line to enable this feature. N consists of the sum of: 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds 1 - undefined instruction events 301da177e4SLinus Torvalds 2 - system calls 311da177e4SLinus Torvalds 4 - invalid data aborts 321da177e4SLinus Torvalds 8 - SIGSEGV faults 331da177e4SLinus Torvalds 16 - SIGBUS faults 341da177e4SLinus Torvalds 351da177e4SLinus Torvaldsconfig DEBUG_ERRORS 361da177e4SLinus Torvalds bool "Verbose kernel error messages" 371da177e4SLinus Torvalds depends on DEBUG_KERNEL 381da177e4SLinus Torvalds help 391da177e4SLinus Torvalds This option controls verbose debugging information which can be 401da177e4SLinus Torvalds printed when the kernel detects an internal error. This debugging 411da177e4SLinus Torvalds information is useful to kernel hackers when tracking down problems, 421da177e4SLinus Torvalds but mostly meaningless to other people. It's safe to say Y unless 431da177e4SLinus Torvalds you are concerned with the code size or don't want to see these 441da177e4SLinus Torvalds messages. 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds# These options are only for real kernel hackers who want to get their hands dirty. 481da177e4SLinus Torvaldsconfig DEBUG_LL 491da177e4SLinus Torvalds bool "Kernel low-level debugging functions" 501da177e4SLinus Torvalds depends on DEBUG_KERNEL 511da177e4SLinus Torvalds help 5235efb606SRussell King Say Y here to include definitions of printascii, printch, printhex 531da177e4SLinus Torvalds in the kernel. This is helpful if you are debugging code that 541da177e4SLinus Torvalds executes before the console is initialized. 551da177e4SLinus Torvalds 561da177e4SLinus Torvaldsconfig DEBUG_ICEDCC 571da177e4SLinus Torvalds bool "Kernel low-level debugging via EmbeddedICE DCC channel" 581da177e4SLinus Torvalds depends on DEBUG_LL 591da177e4SLinus Torvalds help 601da177e4SLinus Torvalds Say Y here if you want the debug print routines to direct their 611da177e4SLinus Torvalds output to the EmbeddedICE macrocell's DCC channel using 621da177e4SLinus Torvalds co-processor 14. This is known to work on the ARM9 style ICE 631da177e4SLinus Torvalds channel. 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds It does include a timeout to ensure that the system does not 661da177e4SLinus Torvalds totally freeze when there is nothing connected to read. 671da177e4SLinus Torvalds 681da177e4SLinus Torvaldsconfig DEBUG_DC21285_PORT 691da177e4SLinus Torvalds bool "Kernel low-level debugging messages via footbridge serial port" 701da177e4SLinus Torvalds depends on DEBUG_LL && FOOTBRIDGE 711da177e4SLinus Torvalds help 721da177e4SLinus Torvalds Say Y here if you want the debug print routines to direct their 731da177e4SLinus Torvalds output to the serial port in the DC21285 (Footbridge). Saying N 741da177e4SLinus Torvalds will cause the debug messages to appear on the first 16550 751da177e4SLinus Torvalds serial port. 761da177e4SLinus Torvalds 771da177e4SLinus Torvaldsconfig DEBUG_CLPS711X_UART2 781da177e4SLinus Torvalds bool "Kernel low-level debugging messages via UART2" 791da177e4SLinus Torvalds depends on DEBUG_LL && ARCH_CLPS711X 801da177e4SLinus Torvalds help 811da177e4SLinus Torvalds Say Y here if you want the debug print routines to direct their 821da177e4SLinus Torvalds output to the second serial port on these devices. Saying N will 831da177e4SLinus Torvalds cause the debug messages to appear on the first serial port. 841da177e4SLinus Torvalds 85*3ec20520SBen Dooksconfig DEBUG_S3C_PORT 86*3ec20520SBen Dooks depends on DEBUG_LL && PLAT_S3C 87*3ec20520SBen Dooks bool "Kernel low-level debugging messages via S3C UART" 881da177e4SLinus Torvalds help 891da177e4SLinus Torvalds Say Y here if you want debug print routines to go to one of the 90*3ec20520SBen Dooks S3C internal UARTs. The chosen UART must have been configured 911da177e4SLinus Torvalds before it is used. 921da177e4SLinus Torvalds 93*3ec20520SBen Dooksconfig DEBUG_S3C_UART 94*3ec20520SBen Dooks depends on PLAT_S3C 95*3ec20520SBen Dooks int "S3C UART to use for low-level debug" 961da177e4SLinus Torvalds default "0" 971da177e4SLinus Torvalds help 98*3ec20520SBen Dooks Choice for UART for kernel low-level using S3C UARTS, 991da177e4SLinus Torvalds should be between zero and two. The port must have been 100c41045a4SEgry Gabor initialised by the boot-loader before use. 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds The uncompressor code port configuration is now handled 103c7657846SBen Dooks by CONFIG_S3C_LOWLEVEL_UART_PORT. 1041da177e4SLinus Torvalds 1051da177e4SLinus Torvaldsendmenu 106