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 for /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_USE_TERMIOS
81 bool "Use termios to manipulate the screen"
83 depends on MORE || TOP || POWERTOP
85 This option allows utilities such as 'more' and 'top' to determine
86 the size of the screen. If you leave this disabled, your utilities
87 that display things on the screen will be especially primitive and
88 will be unable to determine the current screen size, and will be
89 unable to move the cursor.
91 config FEATURE_EDITING
92 bool "Command line editing"
95 Enable line editing (mainly for shell command line).
97 config FEATURE_EDITING_MAX_LEN
98 int "Maximum length of input"
101 depends on FEATURE_EDITING
103 Line editing code uses on-stack buffers for storage.
104 You may want to decrease this parameter if your target machine
105 benefits from smaller stack usage.
107 config FEATURE_EDITING_VI
108 bool "vi-style line editing commands"
110 depends on FEATURE_EDITING
112 Enable vi-style line editing. In shells, this mode can be
113 turned on and off with "set -o vi" and "set +o vi".
115 config FEATURE_EDITING_HISTORY
117 # Don't allow way too big values here, code uses fixed "char *history[N]" struct member
120 depends on FEATURE_EDITING
122 Specify command history size (0 - disable).
124 config FEATURE_EDITING_SAVEHISTORY
125 bool "History saving"
127 depends on FEATURE_EDITING
129 Enable history saving in shells.
131 config FEATURE_EDITING_SAVE_ON_EXIT
132 bool "Save history on shell exit, not after every command"
134 depends on FEATURE_EDITING_SAVEHISTORY
136 Save history on shell exit, not after every command.
138 config FEATURE_REVERSE_SEARCH
139 bool "Reverse history search"
141 depends on FEATURE_EDITING
143 Enable readline-like Ctrl-R combination for reverse history search.
144 Increases code by about 0.5k.
146 config FEATURE_TAB_COMPLETION
147 bool "Tab completion"
149 depends on FEATURE_EDITING
151 Enable tab completion.
153 config FEATURE_USERNAME_COMPLETION
154 bool "Username completion"
156 depends on FEATURE_TAB_COMPLETION
158 Enable username completion.
160 config FEATURE_EDITING_FANCY_PROMPT
161 bool "Fancy shell prompts"
163 depends on FEATURE_EDITING
165 Setting this option allows for prompts to use things like \w and
168 config FEATURE_EDITING_ASK_TERMINAL
169 bool "Query cursor position from terminal"
171 depends on FEATURE_EDITING
173 Allow usage of "ESC [ 6 n" sequence. Terminal answers back with
174 current cursor position. This information is used to make line
175 editing more robust in some cases.
176 If you are not sure whether your terminals respond to this code
177 correctly, or want to save on code size (about 400 bytes),
178 then do not turn this option on.
180 config LOCALE_SUPPORT
181 bool "Enable locale support (system needs locale for this to work)"
184 Enable this if your system has locale support and you would like
185 busybox to support locale settings.
187 config UNICODE_SUPPORT
188 bool "Support Unicode"
191 This makes various applets aware that one byte is not
192 one character on screen.
194 Busybox aims to eventually work correctly with Unicode displays.
195 Any older encodings are not guaranteed to work.
196 Probably by the time when busybox will be fully Unicode-clean,
197 other encodings will be mainly of historic interest.
199 config UNICODE_USING_LOCALE
200 bool "Use libc routines for Unicode (else uses internal ones)"
202 depends on UNICODE_SUPPORT && LOCALE_SUPPORT
204 With this option on, Unicode support is implemented using libc
205 routines. Otherwise, internal implementation is used.
206 Internal implementation is smaller.
208 config FEATURE_CHECK_UNICODE_IN_ENV
209 bool "Check $LC_ALL, $LC_CTYPE and $LANG environment variables"
211 depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
213 With this option on, Unicode support is activated
214 only if locale-related variables have the value of the form
217 Otherwise, Unicode support will be always enabled and active.
220 int "Character code to substitute unprintable characters with"
221 depends on UNICODE_SUPPORT
224 Typical values are 63 for '?' (works with any output device),
225 30 for ASCII substitute control code,
226 65533 (0xfffd) for Unicode replacement character.
228 config LAST_SUPPORTED_WCHAR
229 int "Range of supported Unicode characters"
230 depends on UNICODE_SUPPORT
233 Any character with Unicode value bigger than this is assumed
234 to be non-printable on output device. Many applets replace
235 such characters with substitution character.
237 The idea is that many valid printable Unicode chars
238 nevertheless are not displayed correctly. Think about
239 combining charachers, double-wide hieroglyphs, obscure
240 characters in dozens of ancient scripts...
241 Many terminals, terminal emulators, xterms etc will fail
242 to handle them correctly. Choose the smallest value
243 which suits your needs.
247 767 (0x2ff) - there are no combining chars in [0..767] range
248 (the range includes Latin 1, Latin Ext. A and B),
249 code is ~700 bytes smaller for this case.
250 4351 (0x10ff) - there are no double-wide chars in [0..4351] range,
251 code is ~300 bytes smaller for this case.
252 12799 (0x31ff) - nearly all non-ideographic characters are
253 available in [0..12799] range, including
254 East Asian scripts like katakana, hiragana, hangul,
256 0 - off, any valid printable Unicode character will be printed.
258 config UNICODE_COMBINING_WCHARS
259 bool "Allow zero-width Unicode characters on output"
261 depends on UNICODE_SUPPORT
263 With this option off, any Unicode char with width of 0
264 is substituted on output.
266 config UNICODE_WIDE_WCHARS
267 bool "Allow wide Unicode characters on output"
269 depends on UNICODE_SUPPORT
271 With this option off, any Unicode char with width > 1
272 is substituted on output.
274 config UNICODE_BIDI_SUPPORT
275 bool "Bidirectional character-aware line input"
277 depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
279 With this option on, right-to-left Unicode characters
280 are treated differently on input (e.g. cursor movement).
282 config UNICODE_NEUTRAL_TABLE
283 bool "In bidi input, support non-ASCII neutral chars too"
285 depends on UNICODE_BIDI_SUPPORT
287 In most cases it's enough to treat only ASCII non-letters
288 (i.e. punctuation, numbers and space) as characters
289 with neutral directionality.
290 With this option on, more extensive (and bigger) table
291 of neutral chars will be used.
293 config UNICODE_PRESERVE_BROKEN
294 bool "Make it possible to enter sequences of chars which are not Unicode"
296 depends on UNICODE_SUPPORT
298 With this option on, on line-editing input (such as used by shells)
299 invalid UTF-8 bytes are not substituted with the selected
300 substitution character.
301 For example, this means that entering 'l', 's', ' ', 0xff, [Enter]
302 at shell prompt will list file named 0xff (single char name
303 with char value 255), not file named '?'.
305 config FEATURE_NON_POSIX_CP
306 bool "Non-POSIX, but safer, copying to special nodes"
309 With this option, "cp file symlink" will delete symlink
310 and create a regular file. This does not conform to POSIX,
311 but prevents a symlink attack.
312 Similarly, "cp file device" will not send file's data
313 to the device. (To do that, use "cat file >device")
315 config FEATURE_VERBOSE_CP_MESSAGE
316 bool "Give more precise messages when copy fails (cp, mv etc)"
319 Error messages with this feature enabled:
320 $ cp file /does_not_exist/file
321 cp: cannot create '/does_not_exist/file': Path does not exist
322 $ cp file /vmlinuz/file
323 cp: cannot stat '/vmlinuz/file': Path has non-directory component
324 If this feature is not enabled, they will be, respectively:
325 cp: cannot create '/does_not_exist/file': No such file or directory
326 cp: cannot stat '/vmlinuz/file': Not a directory
327 This will cost you ~60 bytes.
329 config FEATURE_USE_SENDFILE
330 bool "Use sendfile system call"
332 select PLATFORM_LINUX
334 When enabled, busybox will use the kernel sendfile() function
335 instead of read/write loops to copy data between file descriptors
336 (for example, cp command does this a lot).
337 If sendfile() doesn't work, copying code falls back to read/write
338 loop. sendfile() was originally implemented for faster I/O
339 from files to sockets, but since Linux 2.6.33 it was extended
340 to work for many more file types.
342 config FEATURE_COPYBUF_KB
343 int "Copy buffer size, in kilobytes"
347 Size of buffer used by cp, mv, install, wget etc.
348 Buffers which are 4 kb or less will be allocated on stack.
349 Bigger buffers will be allocated with mmap, with fallback to 4 kb
350 stack buffer if mmap fails.
352 config FEATURE_SKIP_ROOTFS
353 bool "Skip rootfs in mount table"
356 Ignore rootfs entry in mount table.
358 In Linux, kernel has a special filesystem, rootfs, which is initially
359 mounted on /. It contains initramfs data, if kernel is configured
360 to have one. Usually, another file system is mounted over / early
361 in boot process, and therefore most tools which manipulate
362 mount table, such as df, will skip rootfs entry.
364 However, some systems do not mount anything on /.
365 If you need to configure busybox for one of these systems,
366 you may find it useful to turn this option off to make df show
367 initramfs statistics.
371 config MONOTONIC_SYSCALL
372 bool "Use clock_gettime(CLOCK_MONOTONIC) syscall"
374 select PLATFORM_LINUX
376 Use clock_gettime(CLOCK_MONOTONIC) syscall for measuring
377 time intervals (time, ping, traceroute etc need this).
378 Probably requires Linux 2.6+. If not selected, gettimeofday
379 will be used instead (which gives wrong results if date/time
382 config IOCTL_HEX2STR_ERROR
383 bool "Use ioctl names rather than hex values in error messages"
386 Use ioctl names rather than hex values in error messages
387 (e.g. VT_DISALLOCATE rather than 0x5608). If disabled this
388 saves about 1400 bytes.
391 bool "Support infiniband HW"
394 Support for printing infiniband addresses in