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Diffstat (limited to 'kernel/arch/blackfin/Kconfig.debug')
| -rw-r--r-- | kernel/arch/blackfin/Kconfig.debug | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/kernel/arch/blackfin/Kconfig.debug b/kernel/arch/blackfin/Kconfig.debug new file mode 100644 index 000000000..f3337ee03 --- /dev/null +++ b/kernel/arch/blackfin/Kconfig.debug @@ -0,0 +1,256 @@ +menu "Kernel hacking" + +source "lib/Kconfig.debug" + +config DEBUG_VERBOSE + bool "Verbose fault messages" + default y + select PRINTK + help + When a program crashes due to an exception, or the kernel detects + an internal error, the kernel can print a not so brief message + explaining what the problem was. This debugging information is + useful to developers and kernel hackers when tracking down problems, + but mostly meaningless to other people. This is always helpful for + debugging but serves no purpose on a production system. + Most people should say N here. + +config DEBUG_MMRS + tristate "Generate Blackfin MMR tree" + select DEBUG_FS + help + Create a tree of Blackfin MMRs via the debugfs tree. If + you enable this, you will find all MMRs laid out in the + /sys/kernel/debug/blackfin/ directory where you can read/write + MMRs directly from userspace. This is obviously just a debug + feature. + +config DEBUG_HWERR + bool "Hardware error interrupt debugging" + depends on DEBUG_KERNEL + help + When enabled, the hardware error interrupt is never disabled, and + will happen immediately when an error condition occurs. This comes + at a slight cost in code size, but is necessary if you are getting + hardware error interrupts and need to know where they are coming + from. + +config EXACT_HWERR + bool "Try to make Hardware errors exact" + depends on DEBUG_HWERR + help + By default, the Blackfin hardware errors are not exact - the error + be reported multiple cycles after the error happens. This delay + can cause the wrong application, or even the kernel to receive a + signal to be killed. If you are getting HW errors in your system, + try turning this on to ensure they are at least coming from the + proper thread. + + On production systems, it is safe (and a small optimization) to say N. + +config DEBUG_DOUBLEFAULT + bool "Debug Double Faults" + default n + help + If an exception is caused while executing code within the exception + handler, the NMI handler, the reset vector, or in emulator mode, + a double fault occurs. On the Blackfin, this is a unrecoverable + event. You have two options: + - RESET exactly when double fault occurs. The excepting + instruction address is stored in RETX, where the next kernel + boot will print it out. + - Print debug message. This is much more error prone, although + easier to handle. It is error prone since: + - The excepting instruction is not committed. + - All writebacks from the instruction are prevented. + - The generated exception is not taken. + - The EXCAUSE field is updated with an unrecoverable event + The only way to check this is to see if EXCAUSE contains the + unrecoverable event value at every exception return. By selecting + this option, you are skipping over the faulting instruction, and + hoping things stay together enough to print out a debug message. + + This does add a little kernel code, but is the only method to debug + double faults - if unsure say "Y" + +choice + prompt "Double Fault Failure Method" + default DEBUG_DOUBLEFAULT_PRINT + depends on DEBUG_DOUBLEFAULT + +config DEBUG_DOUBLEFAULT_PRINT + bool "Print" + +config DEBUG_DOUBLEFAULT_RESET + bool "Reset" + +endchoice + +config DEBUG_HUNT_FOR_ZERO + bool "Catch NULL pointer reads/writes" + default y + help + Say Y here to catch reads/writes to anywhere in the memory range + from 0x0000 - 0x0FFF (the first 4k) of memory. This is useful in + catching common programming errors such as NULL pointer dereferences. + + Misbehaving applications will be killed (generate a SEGV) while the + kernel will trigger a panic. + + Enabling this option will take up an extra entry in CPLB table. + Otherwise, there is no extra overhead. + +config DEBUG_BFIN_HWTRACE_ON + bool "Turn on Blackfin's Hardware Trace" + default y + help + All Blackfins include a Trace Unit which stores a history of the last + 16 changes in program flow taken by the program sequencer. The history + allows the user to recreate the program sequencer’s recent path. This + can be handy when an application dies - we print out the execution + path of how it got to the offending instruction. + + By turning this off, you may save a tiny amount of power. + +choice + prompt "Omit loop Tracing" + default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF + depends on DEBUG_BFIN_HWTRACE_ON + help + The trace buffer can be configured to omit recording of changes in + program flow that match either the last entry or one of the last + two entries. Omitting one of these entries from the record prevents + the trace buffer from overflowing because of any sort of loop (for, do + while, etc) in the program. + + Because zero-overhead Hardware loops are not recorded in the trace buffer, + this feature can be used to prevent trace overflow from loops that + are nested four deep. + +config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF + bool "Trace all Loops" + help + The trace buffer records all changes of flow + +config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE + bool "Compress single-level loops" + help + The trace buffer does not record single loops - helpful if trace + is spinning on a while or do loop. + +config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO + bool "Compress two-level loops" + help + The trace buffer does not record loops two levels deep. Helpful if + the trace is spinning in a nested loop + +endchoice + +config DEBUG_BFIN_HWTRACE_COMPRESSION + int + depends on DEBUG_BFIN_HWTRACE_ON + default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF + default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE + default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO + + +config DEBUG_BFIN_HWTRACE_EXPAND + bool "Expand Trace Buffer greater than 16 entries" + depends on DEBUG_BFIN_HWTRACE_ON + default n + help + By selecting this option, every time the 16 hardware entries in + the Blackfin's HW Trace buffer are full, the kernel will move them + into a software buffer, for dumping when there is an issue. This + has a great impact on performance, (an interrupt every 16 change of + flows) and should normally be turned off, except in those nasty + debugging sessions + +config DEBUG_BFIN_HWTRACE_EXPAND_LEN + int "Size of Trace buffer (in power of 2k)" + range 0 4 + depends on DEBUG_BFIN_HWTRACE_EXPAND + default 1 + help + This sets the size of the software buffer that the trace information + is kept in. + 0 for (2^0) 1k, or 256 entries, + 1 for (2^1) 2k, or 512 entries, + 2 for (2^2) 4k, or 1024 entries, + 3 for (2^3) 8k, or 2048 entries, + 4 for (2^4) 16k, or 4096 entries + +config DEBUG_BFIN_NO_KERN_HWTRACE + bool "Turn off hwtrace in CPLB handlers" + depends on DEBUG_BFIN_HWTRACE_ON + default y + help + The CPLB error handler contains a lot of flow changes which can + quickly fill up the hardware trace buffer. When debugging crashes, + the hardware trace may indicate that the problem lies in kernel + space when in reality an application is buggy. + + Say Y here to disable hardware tracing in some known "jumpy" pieces + of code so that the trace buffer will extend further back. + +config EARLY_PRINTK + bool "Early printk" + default n + select SERIAL_CORE_CONSOLE + help + This option enables special console drivers which allow the kernel + to print messages very early in the bootup process. + + This is useful for kernel debugging when your machine crashes very + early before the console code is initialized. After enabling this + feature, you must add "earlyprintk=serial,uart0,57600" to the + command line (bootargs). It is safe to say Y here in all cases, as + all of this lives in the init section and is thrown away after the + kernel boots completely. + +config NMI_WATCHDOG + bool "Enable NMI watchdog to help debugging lockup on SMP" + default n + depends on SMP + help + If any CPU in the system does not execute the period local timer + interrupt for more than 5 seconds, then the NMI handler dumps debug + information. This information can be used to debug the lockup. + +config CPLB_INFO + bool "Display the CPLB information" + help + Display the CPLB information via /proc/cplbinfo. + +config ACCESS_CHECK + bool "Check the user pointer address" + default y + help + Usually the pointer transfer from user space is checked to see if its + address is in the kernel space. + + Say N here to disable that check to improve the performance. + +config BFIN_ISRAM_SELF_TEST + bool "isram boot self tests" + default n + help + Run some self tests of the isram driver code at boot. + +config BFIN_PSEUDODBG_INSNS + bool "Support pseudo debug instructions" + default n + help + This option allows the kernel to emulate some pseudo instructions which + allow simulator test cases to be run under Linux with no changes. + + Most people should say N here. + +config BFIN_PM_WAKEUP_TIME_BENCH + bool "Display the total time for kernel to resume from power saving mode" + default n + help + Display the total time when kernel resumes normal from standby or + suspend to mem mode. + +endmenu |