tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1menu "Kernel hacking"
2
3source "lib/Kconfig.debug"
4
5config DEBUG_MMRS
6 bool "Generate Blackfin MMR tree"
7 select DEBUG_FS
8 help
9 Create a tree of Blackfin MMRs via the debugfs tree. If
10 you enable this, you will find all MMRs laid out in the
11 /sys/kernel/debug/blackfin/ directory where you can read/write
12 MMRs directly from userspace. This is obviously just a debug
13 feature.
14
15config DEBUG_HWERR
16 bool "Hardware error interrupt debugging"
17 depends on DEBUG_KERNEL
18 help
19 When enabled, the hardware error interrupt is never disabled, and
20 will happen immediately when an error condition occurs. This comes
21 at a slight cost in code size, but is necessary if you are getting
22 hardware error interrupts and need to know where they are coming
23 from.
24
25config DEBUG_ICACHE_CHECK
26 bool "Check Instruction cache coherency"
27 depends on DEBUG_KERNEL
28 depends on DEBUG_HWERR
29 help
30 Say Y here if you are getting weird unexplained errors. This will
31 ensure that icache is what SDRAM says it should be by doing a
32 byte wise comparison between SDRAM and instruction cache. This
33 also relocates the irq_panic() function to L1 memory, (which is
34 un-cached).
35
36config DEBUG_HUNT_FOR_ZERO
37 bool "Catch NULL pointer reads/writes"
38 default y
39 help
40 Say Y here to catch reads/writes to anywhere in the memory range
41 from 0x0000 - 0x0FFF (the first 4k) of memory. This is useful in
42 catching common programming errors such as NULL pointer dereferences.
43
44 Misbehaving applications will be killed (generate a SEGV) while the
45 kernel will trigger a panic.
46
47 Enabling this option will take up an extra entry in CPLB table.
48 Otherwise, there is no extra overhead.
49
50config DEBUG_BFIN_HWTRACE_ON
51 bool "Turn on Blackfin's Hardware Trace"
52 default y
53 help
54 All Blackfins include a Trace Unit which stores a history of the last
55 16 changes in program flow taken by the program sequencer. The history
56 allows the user to recreate the program sequencer’s recent path. This
57 can be handy when an application dies - we print out the execution
58 path of how it got to the offending instruction.
59
60 By turning this off, you may save a tiny amount of power.
61
62choice
63 prompt "Omit loop Tracing"
64 default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
65 depends on DEBUG_BFIN_HWTRACE_ON
66 help
67 The trace buffer can be configured to omit recording of changes in
68 program flow that match either the last entry or one of the last
69 two entries. Omitting one of these entries from the record prevents
70 the trace buffer from overflowing because of any sort of loop (for, do
71 while, etc) in the program.
72
73 Because zero-overhead Hardware loops are not recorded in the trace buffer,
74 this feature can be used to prevent trace overflow from loops that
75 are nested four deep.
76
77config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
78 bool "Trace all Loops"
79 help
80 The trace buffer records all changes of flow
81
82config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
83 bool "Compress single-level loops"
84 help
85 The trace buffer does not record single loops - helpful if trace
86 is spinning on a while or do loop.
87
88config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
89 bool "Compress two-level loops"
90 help
91 The trace buffer does not record loops two levels deep. Helpful if
92 the trace is spinning in a nested loop
93
94endchoice
95
96config DEBUG_BFIN_HWTRACE_COMPRESSION
97 int
98 depends on DEBUG_BFIN_HWTRACE_ON
99 default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
100 default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
101 default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
102
103
104config DEBUG_BFIN_HWTRACE_EXPAND
105 bool "Expand Trace Buffer greater than 16 entries"
106 depends on DEBUG_BFIN_HWTRACE_ON
107 default n
108 help
109 By selecting this option, every time the 16 hardware entries in
110 the Blackfin's HW Trace buffer are full, the kernel will move them
111 into a software buffer, for dumping when there is an issue. This
112 has a great impact on performance, (an interrupt every 16 change of
113 flows) and should normally be turned off, except in those nasty
114 debugging sessions
115
116config DEBUG_BFIN_HWTRACE_EXPAND_LEN
117 int "Size of Trace buffer (in power of 2k)"
118 range 0 4
119 depends on DEBUG_BFIN_HWTRACE_EXPAND
120 default 1
121 help
122 This sets the size of the software buffer that the trace information
123 is kept in.
124 0 for (2^0) 1k, or 256 entries,
125 1 for (2^1) 2k, or 512 entries,
126 2 for (2^2) 4k, or 1024 entries,
127 3 for (2^3) 8k, or 2048 entries,
128 4 for (2^4) 16k, or 4096 entries
129
130config DEBUG_BFIN_NO_KERN_HWTRACE
131 bool "Trace user apps (turn off hwtrace in kernel)"
132 depends on DEBUG_BFIN_HWTRACE_ON
133 default n
134 help
135 Some pieces of the kernel contain a lot of flow changes which can
136 quickly fill up the hardware trace buffer. When debugging crashes,
137 the hardware trace may indicate that the problem lies in kernel
138 space when in reality an application is buggy.
139
140 Say Y here to disable hardware tracing in some known "jumpy" pieces
141 of code so that the trace buffer will extend further back.
142
143config EARLY_PRINTK
144 bool "Early printk"
145 default n
146 help
147 This option enables special console drivers which allow the kernel
148 to print messages very early in the bootup process.
149
150 This is useful for kernel debugging when your machine crashes very
151 early before the console code is initialized. After enabling this
152 feature, you must add "earlyprintk=serial,uart0,57600" to the
153 command line (bootargs). It is safe to say Y here in all cases, as
154 all of this lives in the init section and is thrown away after the
155 kernel boots completely.
156
157config DUAL_CORE_TEST_MODULE
158 tristate "Dual Core Test Module"
159 depends on (BF561)
160 default n
161 help
162 Say Y here to build-in dual core test module for dual core test.
163
164config CPLB_INFO
165 bool "Display the CPLB information"
166 help
167 Display the CPLB information via /proc/cplbinfo.
168
169config ACCESS_CHECK
170 bool "Check the user pointer address"
171 default y
172 help
173 Usually the pointer transfer from user space is checked to see if its
174 address is in the kernel space.
175
176 Say N here to disable that check to improve the performance.
177
178endmenu