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31. INTRODUCTION::
4
5 If you want to add blfs-tool support into an xLFS base system build,
6 read the "BLFS_TOOL SUPPORT" section found in the README and be sure
7 to follow the after-booting installation instructions.
8
9 To automate package builds from the BLFS book instructions is a huge
10 task. Some of the issues are: the BLFS book isn't linear; some package
11 pages use a custom layout; there are circular dependencies; several
12 packages can be installed on a non-default prefix; build commands can
13 change based on what dependencies will be used, etc.
14
15 That being said, the goal of the blfs-tool is to help you solve package
16 dependencies, create build scripts and a Makefile. Not all the auto-generated
17 build scripts and Makefile will work "as is", thus, as a general rule,
18 you will need to review and edit the scripts while reading the book.
19
20
212. PREREQUISITES::
22
23 To use this tool you MUST:
24
25 - have experience building BLFS packages
26 - know how to edit and write shell scripts
27 - know how a Makefile works
28 - be able to trace build failures and to find what is causing it
29 (user error, package bug, BLFS command bug, or jhalfs code bug)
30
31 If you do not have the above skills, please don't use this tool.
32
33
343. USAGE::
35
36 Due to the complexity of the BLFS book, the scripts and Makefile
37 generation is done in several steps:
38
39 3.1 INSTALLED PACKAGES TRACKING SYSTEM::
40
41 This tool includes a very simple tracking system to log which packages
42 have been installed using the tool. It is used to skip installed packages
43 from target selection menu and to test if an installed package has been
44 updated in the BLFS book. Do not rely on this feature as a package
45 management tool.
46
47 The tracking system itself is an XML file: instpkg.xml. It is
48 initialized when <make> is first run in blfs_root. It resides in a
49 directory, which is created when needed during the process of building
50 custom tools or blfs dependencies, right after xLFS. You can specify
51 that directory location in the blfs-tools sub-menu of jhalfs. You may
52 need to update permissions and/or ownership of this directory before
53 using the blfs tool (see README in jhalfs).
54
55 The default location of the tracking directory is /var/lib/jhalfs/BLFS.
56 NB : after the initial build, that directory is only used to contain
57 instpkg.xml, unless custom tools have been built. In the latter case,
58 it also contains empty files whose name are "$PKG-$VERSION" for each
59 versionned package built. The information about those packages is
60 included into instpkg.xml the next time the tool is run.
61
62 3.2 BLFS_TOOL INSTALLATION::
63
64 3.2.1 Normal install
65 The tools are installed just after the building of xLFS, if the
66 appropriate options have been selected in the building menu, as per
67 jhalfs README. If you forgot to select the options and xLFS has been
68 built, it is possible to go back to selecting the appropriate
69 BLFS tools options in the jhalfs menu, then tick `Run makefile'
70 and not `Rebuild files'. You obtain a /blfs_root directory in the
71 root directory of the new xLFS system, which contains the followings:
72
73 blfs-xml/* SVN tree of the selected BLFS book version
74 lib/constants.inc functions libraries
75 /func_dependencies for building the dependency tree
76 menu/* lxdialog and menuconfig source code
77 xsl/gen_pkg_list.xsl XSL stylesheet to generate the package database
78 /gen_config.xsl XSL stylesheet to generate the Config.in file
79 for use in the menuconfig system
80 /dependencies.xsl XSL stylesheet to generate the dependency list
81 of a package
82 /make_book.xsl XSL stylesheet to generate the linear book.xml
83 /scripts.xsl XSL stylesheet to generate the scriptlets from
84 book.xml
85 /bump.xsl XSL stylesheet to update the tracking file
86 README.BLFS this file
87 TODO developers notes (well, not updated often)
88 gen_pkg_book.sh resolves dependencies and generates linear BLFS
89 books and build scripts
90 gen-makefile.sh generates the target Makefile
91 progress_bar.sh the target Makefile progress bar
92 gen-special.sh Helper script for generating the package database
93 Makefile Used by make to update the package database from
94 the SVN tree, then launch the menuconfig interface,
95 and run gen_pkg_book.sh based on configuration
96 settings
97 packdesc.dtd a simple DTD describing the format of the package
98 database and the tracking file.
99 envars.conf envars needed when running the target build scripts
100
101 3.2.2 Install to an already running LFS/BLFS system
102 If you forgot to install the tools when building xLFS, or want to try
103 the tools, you can just run the install-blfs-tools.sh script. It will
104 create the above hierarchy in your home directory and initialize the
105 tracking file. You have first to make sure that the tracking dir exists
106 and is writable by the user. You may also populate it with (empty) files
107 whose names are of the form package-version, for installed packages, so
108 that they are included into the tracking file.
109 3.3.3 Working files
110 Several files are generated during the process:
111
112 packages.xml auto-generated packages database
113 Config.in input file for the menu driven choices
114 configuration file generated by the menuconfig process
115 dependencies/* files recording the dependency tree
116 book.xml the linearized book
117 book-html/* the linearized book rendered in html
118 scripts/* the scriptlets
119
120 From now on, all the work must be done from inside the installation
121 root directory.
122
123 You may move that directory to the $HOME of a non root user, or build
124 as root from that directory.
125
126 3.3 UPDATING BOOK SOURCES::
127
128 If you are using the development book version and you want to update
129 installed packages to the latest version found in that book, you need to
130 update the XML sources and packages database. This is not necessary if
131 you just built xLFS, and you can skip to step 3.4.
132
133 To do that, run "make update". It may happen that the subversion
134 version of your building host is older than the version you just
135 built. This may generate weird errors like "'.' omitted". The easiest
136 thing to do in that case, is to completely remove the blfs-xml directory
137 and run "make update". With recent versions of subversion, you can also
138 run "svn upgrade" from inside the blfs-xml directory.
139
140 On the next configuration run, packages already installed but listed
141 with a new version in the book will be available for target selection
142 and used to solve dependencies.
143
144 3.4 CONFIGURING AND PARSING THE BOOK::
145
146 The next step is to create a book and build scripts in dependency
147 build order for one or several packages.
148
149 Run <make> to launch the configuration interface. The main menu contains
150 two blocks: individual package selection, and build options.
151
152 In the build options section, the dependencies level and default packages
153 used to solve alternatives are set (currently, only for the MTA). You can
154 also select whether the build will be made as a normal user or as root.
155 Those settings are saved to be reused in future configuration runs.
156
157 Note that you may select as many targets as you want, not just one
158 as in the previous version of this tool. But we suggest to not select
159 too many at a time to be able to sort issues!
160
161 When you are done with the menu, a few checks occur, and the dependency
162 chain is generated. Each dependency appears with its priority (required,
163 recommended, optional, or external), and it's level. There is a root level
164 0. The selected packages have level 1. The dependencies of selected packages
165 have level 2, the dependencies of the dependencies have level 3, and so on.
166 When circular dependencies are found, they appear with a priority of
167 "circular". This means that two (or more) dependency chains arrive at the
168 same package. The algorithm chooses the chain with the highest priority and
169 reorders dependencies to remove the other chain(s). This is not always the
170 solution an user would prefer, but we have found no way to do it better.
171
172 You end up with a book.xml file which contains the linearized book,
173 and a rendered HTML, in the directory book-html, which you can browse with
174 "lynx book-html/index.html" (or with any other browser).
175
176 Furthermore, there is a directory "scripts", which contains the generated
177 scriptlets.
178
179 There is also another directory, "dependencies" that contains files
180 generated while resolving dependencies.
181
182 3.5 EDITING BUILD SCRIPTS::
183
184 Now it is time to review the generated book and scripts, making any
185 changes to the scripts necessary to fix generation bugs or to suit your
186 needs.
187
188 Scripts for additional packages (i.e., for non-BLFS packages) can be
189 easily inserted. For example, if you want to install the external dependency
190 "bar" before "foo" package and the "foo" script is named "064-z-foo", you
191 just need to create a "064-y-bar" build script.
192
193 Remember, the package tracking system isn't a package management tool
194 and knows nothing about packages not in the BLFS book.
195
196 Also, review and edit envars.conf. This file is used to set global envars
197 needed by the build scripts.
198
199 3.6 CREATING THE MAKEFILE::
200
201 When the build scripts are ready to be run, the Makefile can be
202 created. Create an empty directory (for example "mkdir work") and cd
203 to that directory. Then run ../gen-makefile.sh
204
205 Review the Makefile, and, if all looks sane, start the build by running
206 "make".
207
2084. GENERATED BUILD SCRIPTS ISSUES::
209
210 In this section, known issues with the generated build scripts are
211 discussed. They are due to build procedures and/or BLFS layout
212 particularities that we can't handle. In several cases, editing the
213 build scripts is mandatory.
214 You may also need to insert some build scripts created by you to resolve
215 unhandled dependencies and/or to remove some script installing an unneeded
216 package (unneeded packages may be pulled in the dependency chain, if
217 they occur as an "or" with another package).
218 When there are circular dependencies (only one known in BLFS 8.0 for
219 recommended dependencies), you may need to move around scripts so that they
220 run in the order script-A script-B script-A. This involves copying script-A
221 to another name (using the xxx-a- fields), and possibly renaming the xxx-a-
222 fields of each involved script.
223
224 4.1 BLFS BOOTSCRIPTS::
225
226 Normally, bootscript installation should work. On the other hand, the
227 book does not give instruction for running them, so you might have to
228 manually insert "/etc/init.d/rc.d/<initscript> start" at some place during
229 the build.
230
231 4.2 PACKAGE CONFIGURATION::
232
233 For those packages that have a "Configuration" section, you should
234 edit the build script to fit the needs of your system. Sometimes, the
235 bash startup files are modified. The shipped 'envars.conf' contains a
236 line 'source /etc/profile', which ensures that the proper environment
237 variables are used.
238
239 4.3 PAGES WITH TWO OR MORE PACKAGES::
240
241 For example: sane, poppler, audacious, freetts, which, etc.
242
243 On the pages for those packages, the BLFS book actually has instructions
244 to download and install two or more packages. You must edit the scripts to
245 fix this. A common pitfall is that the variable PACKAGE may be used for
246 several tarballs. Be sure to save the PACKAGE variable to some other
247 name (for example PKG1, PKG2, etc) after each download. The unpacking
248 instructions may need to be repeated for each tarball in turn.
249
250 4.4 XORG7
251
252 The book has special page layouts for the Xorg7 packages. The tool
253 breaks those pages into individual pages for each packages in the linear
254 book. Also, the menu gives the choice to select each package individually.
255
256 To build the whole Xorg7 chapter, select twm. The (recommended)
257 dependency chain brings in the whole set of Xorg packages.
258
259 4.5 PATCHES
260
261 Please, make sure that all scripts have the commands to download/apply
262 the required patches. Due to book layout issues, some patches may be
263 missing (as of BLFS 8.0, all the patches seem to be downloaded).
264
265 4.6 ROOT COMMANDS
266
267 If building as a normal user (the default setting), be sure that all
268 commands that require root privileges are run using sudo. Also make sure
269 necessary root privilege commands are visible in your PATH. Or use
270 the `Defaults secure_path=' in /etc/sudoers.
271
272 For commands necessitating root privileges, the generated scripts wrap
273 them with the construct:
274 sudo -E sh << ROOT_EOF
275 <commands to be executed as root with `$', ``', and `\' escaped>
276 ROOT_EOF
277 The -E switch ensures the whole environment is passed to the
278 commands to be run with root privileges. It is effective only if the
279 /etc/sudoers file contains `Defaults setenv', or SETENV in the user
280 attributes. If you think it is a security issue, you may forbid this
281 flag in /etc/sudoers, but then, you have to un-escape `$' for variables
282 coming from the environment in the instructions.
283 Although this construct is rather strong, it can fail in some corner
284 cases, so carefully review those instructions.
285
286 WARNING: One variable from the environment is not passed through the
287 -E switch, namely PATH. This is because "sudo" always reset the PATH to
288 the default "secure_path". If you need to have the same PATH as the user
289 "root" would have, you may want to add "source /etc/profile" at the
290 beginning of the commands to be executed as root.
291
292 Due to book layout issues, some sudo commands may be missing.
293
294 4.7 OTHERS
295
296 There may be other issues that we are not aware of. If you find
297 any, please report it to <alfs-discuss@linuxfromscratch.org>.
298
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