Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1menu "Kernel hacking"
2
3source "lib/Kconfig.debug"
4
5config STRICT_DEVMEM
6 bool "Filter access to /dev/mem"
7 depends on MMU
8 ---help---
9 If this option is disabled, you allow userspace (root) access to all
10 of memory, including kernel and userspace memory. Accidental
11 access to this is obviously disastrous, but specific access can
12 be used by people debugging the kernel.
13
14 If this option is switched on, the /dev/mem file only allows
15 userspace access to memory mapped peripherals.
16
17 If in doubt, say Y.
18
19# RMK wants arm kernels compiled with frame pointers or stack unwinding.
20# If you know what you are doing and are willing to live without stack
21# traces, you can get a slightly smaller kernel by setting this option to
22# n, but then RMK will have to kill you ;).
23config FRAME_POINTER
24 bool
25 depends on !THUMB2_KERNEL
26 default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER
27 help
28 If you say N here, the resulting kernel will be slightly smaller and
29 faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
30 when a problem occurs with the kernel, the information that is
31 reported is severely limited.
32
33config ARM_UNWIND
34 bool "Enable stack unwinding support (EXPERIMENTAL)"
35 depends on AEABI && EXPERIMENTAL
36 default y
37 help
38 This option enables stack unwinding support in the kernel
39 using the information automatically generated by the
40 compiler. The resulting kernel image is slightly bigger but
41 the performance is not affected. Currently, this feature
42 only works with EABI compilers. If unsure say Y.
43
44config OLD_MCOUNT
45 bool
46 depends on FUNCTION_TRACER && FRAME_POINTER
47 default y
48
49config DEBUG_USER
50 bool "Verbose user fault messages"
51 help
52 When a user program crashes due to an exception, the kernel can
53 print a brief message explaining what the problem was. This is
54 sometimes helpful for debugging but serves no purpose on a
55 production system. Most people should say N here.
56
57 In addition, you need to pass user_debug=N on the kernel command
58 line to enable this feature. N consists of the sum of:
59
60 1 - undefined instruction events
61 2 - system calls
62 4 - invalid data aborts
63 8 - SIGSEGV faults
64 16 - SIGBUS faults
65
66config DEBUG_STACK_USAGE
67 bool "Enable stack utilization instrumentation"
68 depends on DEBUG_KERNEL
69 help
70 Enables the display of the minimum amount of free stack which each
71 task has ever had available in the sysrq-T output.
72
73# These options are only for real kernel hackers who want to get their hands dirty.
74config DEBUG_LL
75 bool "Kernel low-level debugging functions"
76 depends on DEBUG_KERNEL
77 help
78 Say Y here to include definitions of printascii, printch, printhex
79 in the kernel. This is helpful if you are debugging code that
80 executes before the console is initialized.
81
82config EARLY_PRINTK
83 bool "Early printk"
84 depends on DEBUG_LL
85 help
86 Say Y here if you want to have an early console using the
87 kernel low-level debugging functions. Add earlyprintk to your
88 kernel parameters to enable this console.
89
90config DEBUG_ICEDCC
91 bool "Kernel low-level debugging via EmbeddedICE DCC channel"
92 depends on DEBUG_LL
93 help
94 Say Y here if you want the debug print routines to direct their
95 output to the EmbeddedICE macrocell's DCC channel using
96 co-processor 14. This is known to work on the ARM9 style ICE
97 channel and on the XScale with the PEEDI.
98
99 It does include a timeout to ensure that the system does not
100 totally freeze when there is nothing connected to read.
101
102config OC_ETM
103 bool "On-chip ETM and ETB"
104 select ARM_AMBA
105 help
106 Enables the on-chip embedded trace macrocell and embedded trace
107 buffer driver that will allow you to collect traces of the
108 kernel code.
109
110config DEBUG_DC21285_PORT
111 bool "Kernel low-level debugging messages via footbridge serial port"
112 depends on DEBUG_LL && FOOTBRIDGE
113 help
114 Say Y here if you want the debug print routines to direct their
115 output to the serial port in the DC21285 (Footbridge). Saying N
116 will cause the debug messages to appear on the first 16550
117 serial port.
118
119config DEBUG_CLPS711X_UART2
120 bool "Kernel low-level debugging messages via UART2"
121 depends on DEBUG_LL && ARCH_CLPS711X
122 help
123 Say Y here if you want the debug print routines to direct their
124 output to the second serial port on these devices. Saying N will
125 cause the debug messages to appear on the first serial port.
126
127config DEBUG_S3C_UART
128 depends on PLAT_SAMSUNG
129 int "S3C UART to use for low-level debug"
130 default "0"
131 help
132 Choice for UART for kernel low-level using S3C UARTS,
133 should be between zero and two. The port must have been
134 initialised by the boot-loader before use.
135
136 The uncompressor code port configuration is now handled
137 by CONFIG_S3C_LOWLEVEL_UART_PORT.
138
139endmenu