blob: 738961bf382ad18f39e75f54732833fceebbc9b3 [file] [log] [blame]
Glenn L McGrath90d2bff2004-05-01 00:49:49 +00001Busybox TODO
2
Rob Landleydf4cdaf2006-05-19 20:47:55 +00003Stuff that needs to be done. This is organized by who plans to get around to
4doing it eventually, but that doesn't mean they "own" the item. If you want to
5do one of these bounce an email off the person it's listed under to see if they
6have any suggestions how they plan to go about it, and to minimize conflicts
7between your work and theirs. But otherwise, all of these are fair game.
Glenn L McGrath90d2bff2004-05-01 00:49:49 +00008
Rob Landleydf4cdaf2006-05-19 20:47:55 +00009Rob Landley <rob@landley.net>:
Rob Landley4b146e62006-05-30 18:31:37 +000010 Add BB_NOMMU to platform.h and migrate __uClinux__ tests to that.
11 #if defined __UCLIBC__ && !defined __ARCH_USE_MMU__
Rob Landley0582ee02006-05-29 05:06:06 +000012 Add a libbb/platform.c
13 Implement fdprintf() for platforms that haven't got one.
14 Implement bb_realpath() that can handle NULL on non-glibc.
15 Cleanup bb_asprintf()
16
Rob Landleydf4cdaf2006-05-19 20:47:55 +000017 Migrate calloc() and bb_calloc() occurrences to bb_xzalloc().
18 Remove obsolete _() wrapper crud for internationalization we don't do.
19 Figure out where we need utf8 support, and add it.
20
21 sh
22 The command shell situation is a big mess. We have three or four different
23 shells that don't really share any code, and the "standalone shell" doesn't
24 work all that well (especially not in a chroot environment), due to apps not
25 being reentrant. I'm writing a new shell (bbsh) to unify the various
26 shells and configurably add the minimal set of bash features people
27 actually use. The hardest part is it has to configure down as small as
28 lash while providing lash's features. The rest is easy in comparison.
29 bzip2
30 Compression-side support.
31 init
Bernhard Reutner-Fischer0da069d2006-05-29 12:54:16 +000032 General cleanup (should use ENABLE_FEATURE_INIT_SYSLOG and ENABLE_FEATURE_INIT_DEBUG).
Ned Ludd5df6d9f2006-06-30 21:48:38 +000033 depmod
34 busybox lacks a way to update module deps when running from firmware without the
35 use of the depmod.pl (perl is to bloated for most embedded setups) and or orig
Denis Vlasenko9213a9e2006-09-17 16:28:10 +000036 modutils. The orig depmod is rather pointless to have to add to a firmware image
Ned Ludd5df6d9f2006-06-30 21:48:38 +000037 in when we already have a insmod/rmmod and friends.
Rob Landleydf4cdaf2006-05-19 20:47:55 +000038 Unify base64 handling.
39 There's base64 encoding and decoding going on in:
40 networking/wget.c:base64enc()
41 coreutils/uudecode.c:read_base64()
42 coreutils/uuencode.c:tbl_base64[]
43 networking/httpd.c:decodeBase64()
44 And probably elsewhere. That needs to be unified into libbb functions.
45 Do a SUSv3 audit
46 Look at the full Single Unix Specification version 3 (available online at
47 "http://www.opengroup.org/onlinepubs/009695399/nfindex.html") and
48 figure out which of our apps are compliant, and what we're missing that
49 we might actually care about.
50
51 Even better would be some kind of automated compliance test harness that
52 exercises each command line option and the various corner cases.
53 Internationalization
54 How much internationalization should we do?
55
56 The low hanging fruit is UTF-8 character set support. We should do this.
57 (Vodz pointed out the shell's cmdedit as needing work here. What else?)
58
59 We also have lots of hardwired english text messages. Consolidating this
60 into some kind of message table not only makes translation easier, but
61 also allows us to consolidate redundant (or close) strings.
62
63 We probably don't want to be bloated with locale support. (Not unless we
64 can cleanly export it from our underlying C library without having to
65 concern ourselves with it directly. Perhaps a few specific things like a
66 config option for "date" are low hanging fruit here?)
67
68 What level should things happen at? How much do we care about
69 internationalizing the text console when X11 and xterms are so much better
70 at it? (There's some infrastructure here we don't implement: The
71 "unicode_start" and "unicode_stop" shell scripts need "vt-is-UTF8" and a
72 --unicode option to loadkeys. That implies a real loadkeys/dumpkeys
73 implementation to replace loadkmap/dumpkmap. Plus messing with console font
74 loading. Is it worth it, or do we just say "use X"?)
75
76 Individual compilation of applets.
77 It would be nice if busybox had the option to compile to individual applets,
78 for people who want an alternate implementation less bloated than the gnu
79 utils (or simply with less political baggage), but without it being one big
80 executable.
81
82 Turning libbb into a real dll is another possibility, especially if libbb
83 could export some of the other library interfaces we've already more or less
84 got the code for (like zlib).
85 buildroot - Make a "dogfood" option
86 Busybox 1.1 will be capable of replacing most gnu packages for real world
87 use, such as developing software or in a live CD. It needs wider testing.
88
89 Busybox should now be able to replace bzip2, coreutils, e2fsprogs, file,
90 findutils, gawk, grep, inetutils, less, modutils, net-tools, patch, procps,
91 sed, shadow, sysklogd, sysvinit, tar, util-linux, and vim. The resulting
92 system should be self-hosting (I.E. able to rebuild itself from source
93 code). This means it would need (at least) binutils, gcc, and make, or
94 equivalents.
95
96 It would be a good "eating our own dogfood" test if buildroot had the option
97 of using a "make allyesconfig" busybox instead of the all of the above
98 packages. Anything that's wrong with the resulting system, we can fix. (It
99 would be nice to be able to upgrade busybox to be able to replace bash and
100 diffutils as well, but we're not there yet.)
101
102 One example of an existing system that does this already is Firmware Linux:
103 http://www.landley.net/code/firmware
104 initramfs
105 Busybox should have a sample initramfs build script. This depends on
106 bbsh, mdev, and switch_root.
Rob Landley9c0e4f02006-06-30 16:38:09 +0000107 mkdep
108 Write a mkdep that doesn't segfault if there's a directory it doesn't
109 have permission to read, isn't based on manually editing the output of
110 lexx and yacc, doesn't make such a mess under include/config, etc.
111 Group globals into unions of structures.
112 Go through and turn all the global and static variables into structures,
113 and have all those structures be in a big union shared between processes,
114 so busybox uses less bss. (This is a big win on nommu machines.) See
115 sed.c and mdev.c for examples.
116 Go through bugs.busybox.net and close out all of that somehow.
117 This one's open to everybody, but I'll wind up doing it...
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000118
119
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000120Bernhard Fischer <busybox@busybox.net> suggests to look at these:
Rob Landley0582ee02006-05-29 05:06:06 +0000121 New debug options:
122 -Wlarger-than-127
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000123 Cleanup any big users
124 -Wunused-parameter
125 Facilitate applet PROTOTYPES to provide means for having applets that
126 do a) not take any arguments b) need only one of argc or argv c) need
127 both argc and argv. All of these three options should go for the most
128 feature complete denominator.
Rob Landley0582ee02006-05-29 05:06:06 +0000129 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000130 make bb_common_bufsiz1 configurable, size wise.
131 make pipesize configurable, size wise.
132 Use bb_common_bufsiz1 throughout applets!
Bernhard Reutner-Fischerbe2f9f72006-11-22 16:48:29 +0000133 Add chrt applet. Please CC Bernhard if you suggest a patch.
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000134
135As yet unclaimed:
136
Mike Frysingerb38673f2006-02-02 01:41:53 +0000137----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000138find
Rob Landleyc58fd152005-10-25 20:22:50 +0000139 doesn't understand (), lots of susv3 stuff.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000140----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000141diff
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000142 Make sure we handle empty files properly:
Rob Landley8bcc6e92006-01-09 00:54:46 +0000143 From the patch man page:
144
Mike Frysinger0b7dfb52006-07-27 03:42:30 +0000145 you can remove a file by sending out a context diff that compares
146 the file to be deleted with an empty file dated the Epoch. The
147 file will be removed unless patch is conforming to POSIX and the
148 -E or --remove-empty-files option is not given.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000149---
150patch
Rob Landleyc9c959c2005-10-27 00:57:50 +0000151 Should have simple fuzz factor support to apply patches at an offset which
Rob Landley078bacf2005-09-01 03:02:23 +0000152 shouldn't take up too much space.
Rob Landleyc9c959c2005-10-27 00:57:50 +0000153
154 And while we're at it, a new patch filename quoting format is apparently
155 coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
Rob Landleyf4bb2122005-01-24 06:56:24 +0000156---
157man
158 It would be nice to have a man command. Not one that handles troff or
159 anything, just one that can handle preformatted ascii man pages, possibly
160 compressed. This could probably be a script in the extras directory that
Rob Landleyc58fd152005-10-25 20:22:50 +0000161 calls cat/zcat/bzcat | less
Rob Landley8bcc6e92006-01-09 00:54:46 +0000162
163 (How doclifter might work into this is anybody's guess.)
Rob Landleyf4bb2122005-01-24 06:56:24 +0000164---
Rob Landley8bcc6e92006-01-09 00:54:46 +0000165ar
166 Write support?
Bernhard Reutner-Fischerae114c22007-01-17 19:51:00 +0000167----
168stty / catv
169 stty's visible() function and catv's guts are identical. Merge them into
170 an appropriate libbb function.
171----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000172
173Architectural issues:
174
Rob Landley7b7c99c2005-11-04 20:45:54 +0000175bb_close() with fsync()
176 We should have a bb_close() in place of normal close, with a CONFIG_ option
177 to not just check the return value of close() for an error, but fsync().
178 Close can't reliably report anything useful because if write() accepted the
Rob Landley8bcc6e92006-01-09 00:54:46 +0000179 data then it either went out to the network or it's in cache or a pipe
180 buffer. Either way, there's no guarantee it'll make it to its final
181 destination before close() gets called, so there's no guarantee that any
182 error will be reported.
183
Rob Landley7b7c99c2005-11-04 20:45:54 +0000184 You need to call fsync() if you care about errors that occur after write(),
185 but that can have a big performance impact. So make it a config option.
186---
Rob Landleyf4bb2122005-01-24 06:56:24 +0000187Unify archivers
188 Lots of archivers have the same general infrastructure. The directory
189 traversal code should be factored out, and the guts of each archiver could
190 be some setup code and a series of callbacks for "add this file",
191 "add this directory", "add this symlink" and so on.
192
193 This could clean up tar and zip, and make it cheaper to add cpio and ar
Rob Landley8bcc6e92006-01-09 00:54:46 +0000194 write support, and possibly even cheaply add things like mkisofs or
195 mksquashfs someday, if they become relevant.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000196---
197Text buffer support.
Rob Landleyc58fd152005-10-25 20:22:50 +0000198 Several existing applets (sort, vi, less...) read
Rob Landleyf4bb2122005-01-24 06:56:24 +0000199 a whole file into memory and act on it. There might be an opportunity
200 for shared code in there that could be moved into libbb...
201---
Rob Landley958fa2a2005-06-11 22:10:42 +0000202Memory Allocation
203 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
204 allocation on the stack or the heap. Unfortunately, we're not using it much.
205 We need to audit our memory allocations and turn a lot of malloc/free calls
206 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
Rob Landley1fa4a942006-06-22 22:05:00 +0000207 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
Rob Landleya8821262005-09-16 14:58:55 +0000208
Rob Landley958fa2a2005-06-11 22:10:42 +0000209 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
210 optimized out by the compiler in the stack allocation case (since there's no
211 free for an alloca()), and this means that various cleanup loops that just
212 call free might also be optimized out by the compiler if written right, so
213 we can yank those #ifdefs too, and generally clean up the code.
Rob Landleya8821262005-09-16 14:58:55 +0000214---
215Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
216
217 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
218 that were either defined or undefined to indicate whether the symbol was
219 selected in the .config file. They were used with #ifdefs, ala:
220
221 #ifdef CONFIG_SYMBOL
222 if (other_test) {
223 do_code();
224 }
225 #endif
226
227 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
228 meaning you can still use them for preprocessor tests by replacing
229 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
230 can use them as a true or false test in normal C code:
231
232 if (ENABLE_SYMBOL && other_test) {
233 do_code();
234 }
235
236 (Optimizing away if() statements that resolve to a constant value
237 is known as "dead code elimination", an optimization so old and simple that
238 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
239 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
240 perform dead code elimination.)
241
242 Right now, busybox.h is #including both "config.h" (defining the
243 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
244 point in the future, it would be nice to wean ourselves off of the
245 CONFIG versions. (Among other things, some defective build environments
246 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
247 files. We've experienced collisions before.)
248---
249FEATURE_CLEAN_UP
250 This is more an unresolved issue than a to-do item. More thought is needed.
251
252 Normally we rely on exit() to free memory, close files, and unmap segments
253 for us. This makes most calls to free(), close(), and unmap() optional in
254 busybox applets that don't intend to run for very long, and optional stuff
255 can be omitted to save size.
256
257 The idea was raised that we could simulate fork/exit with setjmp/longjmp
258 for _really_ brainless embedded systems, or speed up the standalone shell
259 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
260 Unfortunately, this isn't as easy as it sounds.
261
262 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
263 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
264 jumps out of the normal flow control and bypasses any cleanup code we
265 put at the end of our applets.
266
Bernhard Reutner-Fischer8c1eda52006-08-28 23:39:36 +0000267 It's possible to add hooks to libbb functions like xmalloc() and xopen()
Rob Landleya8821262005-09-16 14:58:55 +0000268 to add their entries to a linked list, which could be traversed and
269 freed/closed automatically. (This would need to be able to free just the
270 entries after a checkpoint to be usable for a forkless standalone shell.
271 You don't want to free the shell's own resources.)
272
273 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
274 like valgrind happy. It's also documentation of _what_ we're trusting
275 exit() to clean up for us. But new infrastructure to auto-free stuff would
276 render the existing FEATURE_CLEAN_UP code redundant.
277
278 For right now, exit() handles it just fine.
Rob Landley8bcc6e92006-01-09 00:54:46 +0000279
280
281
282Minor stuff:
283 watchdog.c could autodetect the timer duration via:
284 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
285 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
286 kernel types on some distros, which breaks the build.
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000287---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000288 use bb_error_msg where appropriate: See
289 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000290---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000291 use bb_perror_msg where appropriate: See
292 egrep "[^_]perror"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000293---
294 Remove superfluous fmt occurances: e.g.
295 fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
296 -> fprintf(stderr, "unalias: %s not found\n", *argptr);
297---
Bernhard Reutner-Fischer213cc002006-06-04 17:58:19 +0000298 possible code duplication ingroup() and is_a_group_member()
299---
Bernhard Reutner-Fischere02706f2006-07-02 10:33:10 +0000300 Move __get_hz() to a better place and (re)use it in route.c, ash.c, msh.c
301---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000302
Bernhard Reutner-Fischer2677cf12006-01-13 08:46:39 +0000303
304Code cleanup:
305
306Replace deprecated functions.
307
308bzero() -> memset()
309---
310sigblock(), siggetmask(), sigsetmask(), sigmask() -> sigprocmask et al
311---
Bernhard Reutner-Fischer34fc71f2006-04-12 18:50:19 +0000312vdprintf() -> similar sized functionality
313---