2 # For a description of the syntax of this configuration file,
3 # see scripts/kbuild/config-language.txt.
6 menu "Busybox Library Tuning"
11 prompt "Buffer allocation policy"
12 default FEATURE_BUFFERS_USE_MALLOC
14 There are 3 ways BusyBox can handle buffer allocations:
15 - Use malloc. This costs code size for the call to xmalloc.
16 - Put them on stack. For some very small machines with limited stack
17 space, this can be deadly. For most folks, this works just fine.
18 - Put them in BSS. This works beautifully for computers with a real
19 MMU (and OS support), but wastes runtime RAM for uCLinux. This
20 behavior was the only one available for BusyBox versions 0.48 and
23 config FEATURE_BUFFERS_USE_MALLOC
24 bool "Allocate with Malloc"
26 config FEATURE_BUFFERS_GO_ON_STACK
27 bool "Allocate on the Stack"
29 config FEATURE_BUFFERS_GO_IN_BSS
30 bool "Allocate in the .bss section"
34 config PASSWORD_MINLEN
35 int "Minimum password length"
39 Minimum allowable password length.
42 int "MD5: Trade bytes for speed (0:fast, 3:slow)"
43 default 1 # all "fast or small" options default to small
46 Trade binary size versus speed for the md5sum algorithm.
47 Approximate values running uClibc and hashing
48 linux-2.4.4.tar.bz2 were:
49 user times (sec) text size (386)
56 int "SHA3: Trade bytes for speed (0:fast, 1:slow)"
57 default 1 # all "fast or small" options default to small
60 Trade binary size versus speed for the sha3sum algorithm.
61 SHA3_SMALL=0 compared to SHA3_SMALL=1 (approximate):
62 64-bit x86: +270 bytes of code, 45% faster
63 32-bit x86: +450 bytes of code, 75% faster
65 config FEATURE_FAST_TOP
66 bool "Faster /proc scanning code (+100 bytes)"
67 default n # all "fast or small" options default to small
69 This option makes top (and ps) ~20% faster (or 20% less CPU hungry),
70 but code size is slightly bigger.
72 config FEATURE_ETC_NETWORKS
73 bool "Support /etc/networks"
76 Enable support for network names in /etc/networks. This is
77 a rarely used feature which allows you to use names
78 instead of IP/mask pairs in route command.
80 config FEATURE_EDITING
81 bool "Command line editing"
84 Enable line editing (mainly for shell command line).
86 config FEATURE_EDITING_MAX_LEN
87 int "Maximum length of input"
90 depends on FEATURE_EDITING
92 Line editing code uses on-stack buffers for storage.
93 You may want to decrease this parameter if your target machine
94 benefits from smaller stack usage.
96 config FEATURE_EDITING_VI
97 bool "vi-style line editing commands"
99 depends on FEATURE_EDITING
101 Enable vi-style line editing. In shells, this mode can be
102 turned on and off with "set -o vi" and "set +o vi".
104 config FEATURE_EDITING_HISTORY
106 # Don't allow way too big values here, code uses fixed "char *history[N]" struct member
109 depends on FEATURE_EDITING
111 Specify command history size (0 - disable).
113 config FEATURE_EDITING_SAVEHISTORY
114 bool "History saving"
116 depends on FEATURE_EDITING
118 Enable history saving in shells.
120 config FEATURE_EDITING_SAVE_ON_EXIT
121 bool "Save history on shell exit, not after every command"
123 depends on FEATURE_EDITING_SAVEHISTORY
125 Save history on shell exit, not after every command.
127 config FEATURE_REVERSE_SEARCH
128 bool "Reverse history search"
130 depends on FEATURE_EDITING
132 Enable readline-like Ctrl-R combination for reverse history search.
133 Increases code by about 0.5k.
135 config FEATURE_TAB_COMPLETION
136 bool "Tab completion"
138 depends on FEATURE_EDITING
140 config FEATURE_USERNAME_COMPLETION
141 bool "Username completion"
143 depends on FEATURE_TAB_COMPLETION
145 config FEATURE_EDITING_FANCY_PROMPT
146 bool "Fancy shell prompts"
148 depends on FEATURE_EDITING
150 Setting this option allows for prompts to use things like \w and
153 config FEATURE_EDITING_ASK_TERMINAL
154 bool "Query cursor position from terminal"
156 depends on FEATURE_EDITING
158 Allow usage of "ESC [ 6 n" sequence. Terminal answers back with
159 current cursor position. This information is used to make line
160 editing more robust in some cases.
161 If you are not sure whether your terminals respond to this code
162 correctly, or want to save on code size (about 400 bytes),
163 then do not turn this option on.
165 config LOCALE_SUPPORT
166 bool "Enable locale support (system needs locale for this to work)"
169 Enable this if your system has locale support and you would like
170 busybox to support locale settings.
172 config UNICODE_SUPPORT
173 bool "Support Unicode"
176 This makes various applets aware that one byte is not
177 one character on screen.
179 Busybox aims to eventually work correctly with Unicode displays.
180 Any older encodings are not guaranteed to work.
181 Probably by the time when busybox will be fully Unicode-clean,
182 other encodings will be mainly of historic interest.
184 config UNICODE_USING_LOCALE
185 bool "Use libc routines for Unicode (else uses internal ones)"
187 depends on UNICODE_SUPPORT && LOCALE_SUPPORT
189 With this option on, Unicode support is implemented using libc
190 routines. Otherwise, internal implementation is used.
191 Internal implementation is smaller.
193 config FEATURE_CHECK_UNICODE_IN_ENV
194 bool "Check $LC_ALL, $LC_CTYPE and $LANG environment variables"
196 depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
198 With this option on, Unicode support is activated
199 only if locale-related variables have the value of the form
202 Otherwise, Unicode support will be always enabled and active.
205 int "Character code to substitute unprintable characters with"
206 depends on UNICODE_SUPPORT
209 Typical values are 63 for '?' (works with any output device),
210 30 for ASCII substitute control code,
211 65533 (0xfffd) for Unicode replacement character.
213 config LAST_SUPPORTED_WCHAR
214 int "Range of supported Unicode characters"
215 depends on UNICODE_SUPPORT
218 Any character with Unicode value bigger than this is assumed
219 to be non-printable on output device. Many applets replace
220 such characters with substitution character.
222 The idea is that many valid printable Unicode chars
223 nevertheless are not displayed correctly. Think about
224 combining charachers, double-wide hieroglyphs, obscure
225 characters in dozens of ancient scripts...
226 Many terminals, terminal emulators, xterms etc will fail
227 to handle them correctly. Choose the smallest value
228 which suits your needs.
232 767 (0x2ff) - there are no combining chars in [0..767] range
233 (the range includes Latin 1, Latin Ext. A and B),
234 code is ~700 bytes smaller for this case.
235 4351 (0x10ff) - there are no double-wide chars in [0..4351] range,
236 code is ~300 bytes smaller for this case.
237 12799 (0x31ff) - nearly all non-ideographic characters are
238 available in [0..12799] range, including
239 East Asian scripts like katakana, hiragana, hangul,
241 0 - off, any valid printable Unicode character will be printed.
243 config UNICODE_COMBINING_WCHARS
244 bool "Allow zero-width Unicode characters on output"
246 depends on UNICODE_SUPPORT
248 With this option off, any Unicode char with width of 0
249 is substituted on output.
251 config UNICODE_WIDE_WCHARS
252 bool "Allow wide Unicode characters on output"
254 depends on UNICODE_SUPPORT
256 With this option off, any Unicode char with width > 1
257 is substituted on output.
259 config UNICODE_BIDI_SUPPORT
260 bool "Bidirectional character-aware line input"
262 depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
264 With this option on, right-to-left Unicode characters
265 are treated differently on input (e.g. cursor movement).
267 config UNICODE_NEUTRAL_TABLE
268 bool "In bidi input, support non-ASCII neutral chars too"
270 depends on UNICODE_BIDI_SUPPORT
272 In most cases it's enough to treat only ASCII non-letters
273 (i.e. punctuation, numbers and space) as characters
274 with neutral directionality.
275 With this option on, more extensive (and bigger) table
276 of neutral chars will be used.
278 config UNICODE_PRESERVE_BROKEN
279 bool "Make it possible to enter sequences of chars which are not Unicode"
281 depends on UNICODE_SUPPORT
283 With this option on, on line-editing input (such as used by shells)
284 invalid UTF-8 bytes are not substituted with the selected
285 substitution character.
286 For example, this means that entering 'l', 's', ' ', 0xff, [Enter]
287 at shell prompt will list file named 0xff (single char name
288 with char value 255), not file named '?'.
290 config FEATURE_NON_POSIX_CP
291 bool "Non-POSIX, but safer, copying to special nodes"
294 With this option, "cp file symlink" will delete symlink
295 and create a regular file. This does not conform to POSIX,
296 but prevents a symlink attack.
297 Similarly, "cp file device" will not send file's data
298 to the device. (To do that, use "cat file >device")
300 config FEATURE_VERBOSE_CP_MESSAGE
301 bool "Give more precise messages when copy fails (cp, mv etc)"
304 Error messages with this feature enabled:
305 $ cp file /does_not_exist/file
306 cp: cannot create '/does_not_exist/file': Path does not exist
307 $ cp file /vmlinuz/file
308 cp: cannot stat '/vmlinuz/file': Path has non-directory component
309 If this feature is not enabled, they will be, respectively:
310 cp: cannot create '/does_not_exist/file': No such file or directory
311 cp: cannot stat '/vmlinuz/file': Not a directory
312 This will cost you ~60 bytes.
314 config FEATURE_USE_SENDFILE
315 bool "Use sendfile system call"
317 select PLATFORM_LINUX
319 When enabled, busybox will use the kernel sendfile() function
320 instead of read/write loops to copy data between file descriptors
321 (for example, cp command does this a lot).
322 If sendfile() doesn't work, copying code falls back to read/write
323 loop. sendfile() was originally implemented for faster I/O
324 from files to sockets, but since Linux 2.6.33 it was extended
325 to work for many more file types.
327 config FEATURE_COPYBUF_KB
328 int "Copy buffer size, in kilobytes"
332 Size of buffer used by cp, mv, install, wget etc.
333 Buffers which are 4 kb or less will be allocated on stack.
334 Bigger buffers will be allocated with mmap, with fallback to 4 kb
335 stack buffer if mmap fails.
337 config FEATURE_SKIP_ROOTFS
338 bool "Skip rootfs in mount table"
341 Ignore rootfs entry in mount table.
343 In Linux, kernel has a special filesystem, rootfs, which is initially
344 mounted on /. It contains initramfs data, if kernel is configured
345 to have one. Usually, another file system is mounted over / early
346 in boot process, and therefore most tools which manipulate
347 mount table, such as df, will skip rootfs entry.
349 However, some systems do not mount anything on /.
350 If you need to configure busybox for one of these systems,
351 you may find it useful to turn this option off to make df show
352 initramfs statistics.
356 config MONOTONIC_SYSCALL
357 bool "Use clock_gettime(CLOCK_MONOTONIC) syscall"
359 select PLATFORM_LINUX
361 Use clock_gettime(CLOCK_MONOTONIC) syscall for measuring
362 time intervals (time, ping, traceroute etc need this).
363 Probably requires Linux 2.6+. If not selected, gettimeofday
364 will be used instead (which gives wrong results if date/time
367 config IOCTL_HEX2STR_ERROR
368 bool "Use ioctl names rather than hex values in error messages"
371 Use ioctl names rather than hex values in error messages
372 (e.g. VT_DISALLOCATE rather than 0x5608). If disabled this
373 saves about 1400 bytes.
376 bool "Support infiniband HW"
379 Support for printing infiniband addresses in