3 source "lib/Kconfig.debug"
9 bool "Generate Blackfin MMR tree"
12 Create a tree of Blackfin MMRs via the debugfs tree. If
13 you enable this, you will find all MMRs laid out in the
14 /sys/kernel/debug/blackfin/ directory where you can read/write
15 MMRs directly from userspace. This is obviously just a debug
19 bool "Hardware error interrupt debugging"
20 depends on DEBUG_KERNEL
22 When enabled, the hardware error interrupt is never disabled, and
23 will happen immediately when an error condition occurs. This comes
24 at a slight cost in code size, but is necessary if you are getting
25 hardware error interrupts and need to know where they are coming
28 config DEBUG_DOUBLEFAULT
29 bool "Debug Double Faults"
32 If an exception is caused while executing code within the exception
33 handler, the NMI handler, the reset vector, or in emulator mode,
34 a double fault occurs. On the Blackfin, this is a unrecoverable
35 event. You have two options:
36 - RESET exactly when double fault occurs. The excepting
37 instruction address is stored in RETX, where the next kernel
38 boot will print it out.
39 - Print debug message. This is much more error prone, although
40 easier to handle. It is error prone since:
41 - The excepting instruction is not committed.
42 - All writebacks from the instruction are prevented.
43 - The generated exception is not taken.
44 - The EXCAUSE field is updated with an unrecoverable event
45 The only way to check this is to see if EXCAUSE contains the
46 unrecoverable event value at every exception return. By selecting
47 this option, you are skipping over the faulting instruction, and
48 hoping things stay together enough to print out a debug message.
50 This does add a little kernel code, but is the only method to debug
51 double faults - if unsure say "Y"
54 prompt "Double Fault Failure Method"
55 default DEBUG_DOUBLEFAULT_PRINT
56 depends on DEBUG_DOUBLEFAULT
58 config DEBUG_DOUBLEFAULT_PRINT
61 config DEBUG_DOUBLEFAULT_RESET
66 config DEBUG_ICACHE_CHECK
67 bool "Check Instruction cache coherency"
68 depends on DEBUG_KERNEL
69 depends on DEBUG_HWERR
71 Say Y here if you are getting weird unexplained errors. This will
72 ensure that icache is what SDRAM says it should be by doing a
73 byte wise comparison between SDRAM and instruction cache. This
74 also relocates the irq_panic() function to L1 memory, (which is
77 config DEBUG_HUNT_FOR_ZERO
78 bool "Catch NULL pointer reads/writes"
81 Say Y here to catch reads/writes to anywhere in the memory range
82 from 0x0000 - 0x0FFF (the first 4k) of memory. This is useful in
83 catching common programming errors such as NULL pointer dereferences.
85 Misbehaving applications will be killed (generate a SEGV) while the
86 kernel will trigger a panic.
88 Enabling this option will take up an extra entry in CPLB table.
89 Otherwise, there is no extra overhead.
91 config DEBUG_BFIN_HWTRACE_ON
92 bool "Turn on Blackfin's Hardware Trace"
95 All Blackfins include a Trace Unit which stores a history of the last
96 16 changes in program flow taken by the program sequencer. The history
97 allows the user to recreate the program sequencer’s recent path. This
98 can be handy when an application dies - we print out the execution
99 path of how it got to the offending instruction.
101 By turning this off, you may save a tiny amount of power.
104 prompt "Omit loop Tracing"
105 default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
106 depends on DEBUG_BFIN_HWTRACE_ON
108 The trace buffer can be configured to omit recording of changes in
109 program flow that match either the last entry or one of the last
110 two entries. Omitting one of these entries from the record prevents
111 the trace buffer from overflowing because of any sort of loop (for, do
112 while, etc) in the program.
114 Because zero-overhead Hardware loops are not recorded in the trace buffer,
115 this feature can be used to prevent trace overflow from loops that
116 are nested four deep.
118 config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
119 bool "Trace all Loops"
121 The trace buffer records all changes of flow
123 config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
124 bool "Compress single-level loops"
126 The trace buffer does not record single loops - helpful if trace
127 is spinning on a while or do loop.
129 config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
130 bool "Compress two-level loops"
132 The trace buffer does not record loops two levels deep. Helpful if
133 the trace is spinning in a nested loop
137 config DEBUG_BFIN_HWTRACE_COMPRESSION
139 depends on DEBUG_BFIN_HWTRACE_ON
140 default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
141 default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
142 default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
145 config DEBUG_BFIN_HWTRACE_EXPAND
146 bool "Expand Trace Buffer greater than 16 entries"
147 depends on DEBUG_BFIN_HWTRACE_ON
150 By selecting this option, every time the 16 hardware entries in
151 the Blackfin's HW Trace buffer are full, the kernel will move them
152 into a software buffer, for dumping when there is an issue. This
153 has a great impact on performance, (an interrupt every 16 change of
154 flows) and should normally be turned off, except in those nasty
157 config DEBUG_BFIN_HWTRACE_EXPAND_LEN
158 int "Size of Trace buffer (in power of 2k)"
160 depends on DEBUG_BFIN_HWTRACE_EXPAND
163 This sets the size of the software buffer that the trace information
165 0 for (2^0) 1k, or 256 entries,
166 1 for (2^1) 2k, or 512 entries,
167 2 for (2^2) 4k, or 1024 entries,
168 3 for (2^3) 8k, or 2048 entries,
169 4 for (2^4) 16k, or 4096 entries
171 config DEBUG_BFIN_NO_KERN_HWTRACE
172 bool "Trace user apps (turn off hwtrace in kernel)"
173 depends on DEBUG_BFIN_HWTRACE_ON
176 Some pieces of the kernel contain a lot of flow changes which can
177 quickly fill up the hardware trace buffer. When debugging crashes,
178 the hardware trace may indicate that the problem lies in kernel
179 space when in reality an application is buggy.
181 Say Y here to disable hardware tracing in some known "jumpy" pieces
182 of code so that the trace buffer will extend further back.
188 This option enables special console drivers which allow the kernel
189 to print messages very early in the bootup process.
191 This is useful for kernel debugging when your machine crashes very
192 early before the console code is initialized. After enabling this
193 feature, you must add "earlyprintk=serial,uart0,57600" to the
194 command line (bootargs). It is safe to say Y here in all cases, as
195 all of this lives in the init section and is thrown away after the
196 kernel boots completely.
199 bool "Display the CPLB information"
201 Display the CPLB information via /proc/cplbinfo.
204 bool "Check the user pointer address"
207 Usually the pointer transfer from user space is checked to see if its
208 address is in the kernel space.
210 Say N here to disable that check to improve the performance.