From 725428da433a9c243bd4122e3eee1fdcafef21f9 Mon Sep 17 00:00:00 2001 From: Bill Traynor Date: Tue, 23 Apr 2013 15:01:56 -0400 Subject: er-manual-metadata: Stripping all end of line whitespace. Removed all trailing whitespace. Signed-off-by: Bill Traynor --- doc/user-manual/user-manual-metadata.xml | 568 +++++++++++++++---------------- 1 file changed, 279 insertions(+), 289 deletions(-) diff --git a/doc/user-manual/user-manual-metadata.xml b/doc/user-manual/user-manual-metadata.xml index 66f49f63a..15e0d45a0 100644 --- a/doc/user-manual/user-manual-metadata.xml +++ b/doc/user-manual/user-manual-metadata.xml @@ -12,7 +12,7 @@ and how they interact. BitBake handles the parsing and execution of the data files. - The data itself is of various types: + The data itself is of various types: @@ -21,7 +21,6 @@ of software. - Class Data: @@ -34,7 +33,7 @@ Configuration Data:Defines machine-specific settings, policy decisions, etc. Configuration data acts as the glue to bind everything - together. + together. @@ -53,11 +52,10 @@ VARIABLE = "value" - In this example, - VARIABLE is + In this example, + VARIABLE is value. -
Variable Expansion BitBake supports variables referencing one another's contents using @@ -65,79 +63,75 @@ - A = "aval" + A = "aval" B = "pre${A}post" - This results in - A containing - aval and - B containing + This results in + A containing + aval and + B containing preavalpost.
-
Setting a Default Value (?=) A?= "aval" - If + If A is set before the above is called, it - will retain its previous value. If - A is unset prior to the above call, - A will be set to + will retain its previous value. If + A is unset prior to the above call, + A will be set to aval. Note that this assignment is immediate, so if there are multiple ?= assignments to a single variable, the first of those will be used.
-
Setting a Weak Default Value (??=) - A??= "somevalue" + A??= "somevalue" A??= "someothervalue" - If - A + If + A is set before the above, it will retain that value. - If - A - is unset prior to the above, - A - will be set to someothervalue. + If + A + is unset prior to the above, + A + will be set to someothervalue. This is a lazy/weak assignment in that the assignment does not occur until the end of the parsing process, so that the last, - rather than the first, ??= assignment to a given variable will + rather than the first, ??= assignment to a given variable will be used. Any other setting of A using = or ?= will however override the value set with ??=.
-
Immediate Variable Expansion (:=) := results in a variable's contents being expanded immediately, rather than when the variable is actually used. - - T = "123" - A:= "${B} ${A} test ${T}" - T = "456" - B = "${T} bval" - C = "cval" + T = "123" + A:= "${B} ${A} test ${T}" + T = "456" + B = "${T} bval" + C = "cval" C:= "${C}append" - In this example, - A + In this example, + A would contain test 123, - B + B would contain 456 bval, and - C + C would be cvalappend. @@ -147,18 +141,18 @@ Appending (+=) and Prepending (=+) - B = "bval" - B+= "additionaldata" - C = "cval" + B = "bval" + B+= "additionaldata" + C = "cval" C=+ "test" - In this example, - B + In this example, + B is now - bval additionaldata + bval additionaldata and - C - is + C + is test cval.
@@ -166,18 +160,18 @@ Appending (.=) and Prepending (=.) without spaces - B = "bval" - B.= "additionaldata" - C = "cval" + B = "bval" + B.= "additionaldata" + C = "cval" C=. "test" In this example, B is now - bvaladditionaldata - and - C - is + bvaladditionaldata + and + C + is testcval. In contrast to the above appending and prepending operators, no additional space will be introduced. @@ -205,9 +199,9 @@ yourself.
Variable Flags - Variables can have associated flags which provide a way of + Variables can have associated flags which provide a way of tagging extra information onto a variable. - Several flags are used internally by BitBake but they can be + Several flags are used internally by BitBake but they can be used externally too if needed. The standard operations mentioned above also work on flags. @@ -220,14 +214,13 @@ yourself. In this example, - VARIABLE - has a flag, - SOMEFLAG - that is set to + VARIABLE + has a flag, + SOMEFLAG + that is set to value.
-
Inline Python variable expansion @@ -237,7 +230,7 @@ yourself. This would result in the - DATE + DATE variable containing today's date.
@@ -245,56 +238,54 @@ yourself.
Conditional Syntax (Overrides) -
Conditional Metadata - OVERRIDES is a - : + OVERRIDES is a + : separated variable containing each item you want to satisfy conditions. So, if you have a variable that is conditional on arm, and - arm - is in OVERRIDES, then the - arm + arm + is in OVERRIDES, then the + arm specific version of the variable is used rather than the non-conditional version. Example: - OVERRIDES - = "architecture:os:machine" - TEST - = "defaultvalue" - TEST_os - = "osspecificvalue" - TEST_condnotinoverrides + OVERRIDES + = "architecture:os:machine" + TEST + = "defaultvalue" + TEST_os + = "osspecificvalue" + TEST_condnotinoverrides = "othercondvalue" - In this example, - TEST - would be osspecificvalue, + In this example, + TEST + would be osspecificvalue, due to the condition - os being in + os being in OVERRIDES.
-
Conditional Appending - BitBake also supports appending and prepending to variables + BitBake also supports appending and prepending to variables based on whether something is in OVERRIDES. Example: - DEPENDS - = "glibc ncurses" - OVERRIDES - = "machine:local" - DEPENDS_append_machine + DEPENDS + = "glibc ncurses" + OVERRIDES + = "machine:local" + DEPENDS_append_machine = "libmad" @@ -306,82 +297,81 @@ yourself.
Variable Interaction: Worked Examples - Despite the documentation of the different forms of variable - definition above, it can be hard to work out what happens when + Despite the documentation of the different forms of variable + definition above, it can be hard to work out what happens when variable operators are combined. - This section documents some common questions people have + This section documents some common questions people have regarding the way variables interact.
-
Override and Append Ordering - There is often confusion about which order overrides and the + There is often confusion about which order overrides and the various append operators take effect. - OVERRIDES - = "foo" - A_foo_append + OVERRIDES + = "foo" + A_foo_append = "X" - In this case, X is unconditionally appended to the variable - A_foo. - Since foo is an override, A_foo would then replace + In this case, X is unconditionally appended to the variable + A_foo. + Since foo is an override, A_foo would then replace A. - OVERRIDES - = "foo" - A - = "X" - A_append_foo + OVERRIDES + = "foo" + A + = "X" + A_append_foo = "Y" In this case, only when foo is in OVERRIDES, Y is appended to the - variable - A - so the value of - A + variable + A + so the value of + A would become XY (NB: no spaces are appended). - OVERRIDES - = "foo" - A_foo_append - = "X" + OVERRIDES + = "foo" + A_foo_append + = "X" A_foo_append += "Y" This behaves as per the first case above, but the value of - A + A would be "X Y" instead of just "X". - A - = "1" - A_append - = "2" - A_append - = "3" A - += "4" + = "1" + A_append + = "2" + A_append + = "3" + A + += "4" A .= "5" - Would ultimately result in - A - taking the value "1 4523" since the _append operator executes + Would ultimately result in + A + taking the value "1 4523" since the _append operator executes at the same time as the expansion of other overrides.
- +
Key Expansion Key expansion happens at the data store finalisation time just @@ -389,84 +379,84 @@ yourself. - A${B} + A${B} = "X" - B - = "2" - A2 + B + = "2" + A2 = "Y" - So in this case - A2 + So in this case + A2 would take the value of "X".
- +
Inheritance
Inheritance - NOTE: This is only supported in .bb + NOTE: This is only supported in .bb and .bbclass files. The inherit directive is a means of specifying what classes of functionality your .bb requires. It is a rudimentary form of inheritance. For example, you can easily abstract out the tasks involved in - building a package that uses autoconf and automake, and put - that into a bbclass for your packages to make use of. - A given bbclass is located by searching for - classes/filename.bbclass in - BBPATH, + building a package that uses autoconf and automake, and put + that into a bbclass for your packages to make use of. + A given bbclass is located by searching for + classes/filename.bbclass in + BBPATH, where filename is what you inherited.
Inclusion - Next, there is the + Next, there is the include directive, that causes BitBake to parse whatever file you specify, and insert it at that location, which is not unlike Make. However, if the path specified on the - include + include line is a relative path, BitBake will locate the first one it - can find within + can find within BBPATH. FIX ME: This section requires improvement.
- +
Requiring Inclusion - In contrast to the - include - directive, - require + In contrast to the + include + directive, + require will raise a ParseError if the file to be included cannot be found. - Otherwise it will behave just like the - include + Otherwise it will behave just like the + include directive. FIX ME: This section requires improvement. - +
- +
INHERIT Configuration Directive - This configuration directive causes the named class to be inherited at + This configuration directive causes the named class to be inherited at this point during parsing. This variable is only valid in configuration files. - + - +
@@ -474,7 +464,7 @@ yourself. Defining Python Functions into the Global Python Namespace - NOTE: + NOTE: This is only supported in .bb and .bbclass files. @@ -488,23 +478,23 @@ yourself. if d.getVar('SOMECONDITION', True): return "dependencywithcond" else: - return "dependency" - SOMECONDITION = "1" + return "dependency" + SOMECONDITION = "1" DEPENDS = "${@get_depends(d)}" - This would result in - DEPENDS - containing + This would result in + DEPENDS + containing dependencywithcond.
- +
Functions NOTE: This is only supported in .bb and .bbclass files. As with most languages, functions are the building blocks that - define operations. + define operations. Bitbake supports shell and python functions. An example shell function definition is: @@ -524,7 +514,7 @@ python some_python_function () { there is no need to import those module. The datastore, "d" is also a global variable and always available to these functions automatically. - + Bitbake will execute functions of this form using bb.build.exec_func() which can also be called from python functions to execute other functions, either shell or python based. @@ -540,8 +530,8 @@ def some_python_function(arg1, arg2): The difference is that the second form takes parameters, the datastore is not available automatically and must be passed as a parameter and these functions are not called with exec_func() but are executed with -direct python function calls. -The "bb" and "os" modules are still automatically available and there is no +direct python function calls. +The "bb" and "os" modules are still automatically available and there is no need to import them.
@@ -549,14 +539,14 @@ need to import them.
Tasks - NOTE: + NOTE: This is only supported in .bb and .bbclass files. A shell or python function executable through exec_func can be promoted to become a task. - Tasks are the execution unit Bitbake uses and each step that needs to be run - for a given .bb is known as a task. - There is a addtask command to add new tasks and promote functions which by + Tasks are the execution unit Bitbake uses and each step that needs to be run + for a given .bb is known as a task. + There is a addtask command to add new tasks and promote functions which by convention must start with “do_”. The addtask command is also used to describe intertask dependencies. @@ -576,56 +566,56 @@ need to import them. being run first.
- +
Task Flags - Tasks support a number of flags which control various + Tasks support a number of flags which control various functionality of the task. These are as follows: - 'dirs' - directories which should be created before the task + 'dirs' - directories which should be created before the task runs - 'cleandirs' - directories which should created before the task + 'cleandirs' - directories which should created before the task runs but should be empty - 'noexec' - marks the tasks as being empty and no execution + 'noexec' - marks the tasks as being empty and no execution required. These are used as dependency placeholders or used when added tasks need to be subsequently disabled. - 'nostamp' - don't generate a stamp file for a task. + 'nostamp' - don't generate a stamp file for a task. This means the task is always executed. 'fakeroot' - this task needs to be run in a fakeroot - environment, obtained by adding the variables in FAKEROOTENV + environment, obtained by adding the variables in FAKEROOTENV to the environment. 'umask' - the umask to run the task under. - For the 'deptask', 'rdeptask', 'depends', 'rdepends'and + For the 'deptask', 'rdeptask', 'depends', 'rdepends'and 'recrdeptask' flags please see the dependencies section.
- +
Parsing and Execution
Parsing Overview - BitBake parses configuration files, classes, and + BitBake parses configuration files, classes, and .bb files. - The first thing BitBake does is look for the + The first thing BitBake does is look for the bitbake.conf file. This file resides in the within the /conf/ directory. BitBake finds it by examining its BBPATH - environment variable and looking for the + environment variable and looking for the /conf/ directory. @@ -643,7 +633,7 @@ need to import them. The DISTRO and MACHINE BitBake environment variables are both usually set in the local.conf file. - Valid distribution configuration files are available in the + Valid distribution configuration files are available in the /conf/distro/ directory and valid machine configuration files in the meta/conf/machine/ directory. @@ -654,22 +644,22 @@ need to import them. - After parsing of the configuration files, some standard classes are + After parsing of the configuration files, some standard classes are included. The base.bbclass file is always included. Other classes that are specified in the configuration using the INHERIT variable are also included. Class files are searched for in a classes - subdirectory under the paths in BBPATH in the + subdirectory under the paths in BBPATH in the same way as configuration files. - After classes are included, the variable + After classes are included, the variable BBFILES is set, usually in - local.conf, and defines the list of places to + local.conf, and defines the list of places to search for .bb files. - Adding extra content to BBFILES is best + Adding extra content to BBFILES is best achieved through the use of BitBake layers as described in the Layers section below. @@ -692,12 +682,12 @@ need to import them. configuration files or class files on which the .bb file depends change. -
+
Configuration files Prior to parsing configuration files, Bitbake looks at certain variables, including: - + BB-ENV-WHITELIST BB_PRESERVE-ENV @@ -710,33 +700,33 @@ need to import them. The first kind of metadata in BitBake is configuration metadata. This metadata is global, and therefore affects - all + all packages and tasks that are executed. - BitBake will first search the current working directory - for an optional "conf/bblayers.conf" configuration + BitBake will first search the current working directory + for an optional "conf/bblayers.conf" configuration file. - This file is expected to contain a BBLAYERS variable + This file is expected to contain a BBLAYERS variable that is a space delimited list of 'layer' directories. - For each directory in this list, a "conf/layer.conf" - file will be searched for and parsed with the LAYERDIR + For each directory in this list, a "conf/layer.conf" + file will be searched for and parsed with the LAYERDIR variable being set to the directory where the layer was found. - The idea is these files will setup BBPATH and other + The idea is these files will setup BBPATH and other variables correctly for a given build directory automatically for the user. BitBake will then expect to find 'conf/bitbake.conf' - somewhere in the user specified - BBPATH. - That configuration file generally has include - directives to pull in any other metadata (generally + somewhere in the user specified + BBPATH. + That configuration file generally has include + directives to pull in any other metadata (generally files specific to architecture, machine, localand so on). Only variable definitions and include directives are allowed in .conf files. The following variables include: - + BITBAKE_UI BBDEBUG @@ -764,7 +754,7 @@ need to import them. working on a single project. However, the more modular you organize your Metadata, the easier it is to cope with future changes. - + To illustrate how layers are used to keep things modular, consider machine customizations. @@ -791,7 +781,7 @@ need to import them.
- +
Schedulers @@ -802,26 +792,26 @@ need to import them.
- +
Classes - BitBake classes are our rudimentary inheritance mechanism. - As briefly mentioned in the metadata introduction, they're + BitBake classes are our rudimentary inheritance mechanism. + As briefly mentioned in the metadata introduction, they're parsed when an - inherit - directive is encountered, and they are located in classes/ + inherit + directive is encountered, and they are located in classes/ relative to the directories in BBPATH.
- +
.bb files A BitBake (.bb) file is a logical unit of tasks to be executed. Normally this is a package to be built. Inter-.bb dependencies are obeyed. - The files themselves are located via the - BBFILES + The files themselves are located via the + BBFILES variable, which is set to a space separated list of .bb files, and does handle wildcards. @@ -831,14 +821,14 @@ need to import them.
Events - NOTE: + NOTE: This is only supported in .bb and .bbclass files. BitBake allows installation of event handlers. - Events are triggered at certain points during operation, such + Events are triggered at certain points during operation, such as the beginning of operation against a given .bb, the start of a given task, task failure, task success, et cetera. - The intent is to make it easy to do things like email + The intent is to make it easy to do things like email notification on build failure. @@ -850,23 +840,23 @@ need to import them. This event handler gets called every time an event is triggered. - A global variable - e - is defined. + A global variable + e + is defined. e.data contains an instance of bb.data. - With the getName(e) method one can get the + With the getName(e) method one can get the name of the triggered event. - The above event handler prints the name of the event and the - content of the - FILE + The above event handler prints the name of the event and the + content of the + FILE variable. - + During a Build, the following common events occur: - + bb.event.ConfigParsed() bb.event.ParseStarted() bb.event.ParseProgress() @@ -899,27 +889,27 @@ There are also other events that occur based on specific requests to the server:
- +
Variants - Class Extension Mechanism Two BitBake features exist to facilitate the creation of multiple buildable incarnations from a single recipe file. - The first is - BBCLASSEXTEND. - This variable is a space separated list of classes used to + The first is + BBCLASSEXTEND. + This variable is a space separated list of classes used to "extend" the recipe for each variant. As an example, setting - BBCLASSEXTEND = "native" + BBCLASSEXTEND = "native" results in a second incarnation of the current recipe being available. - This second incarnation will have the "native" class + This second incarnation will have the "native" class inherited. The second feature is - BBVERSIONS. + BBVERSIONS. This variable allows a single recipe to build multiple versions - of a project from a single recipe file, and allows you to + of a project from a single recipe file, and allows you to specify conditional metadata (using the OVERRIDES mechanism) for a single version, or an optionally named range of versions: @@ -930,34 +920,34 @@ There are also other events that occur based on specific requests to the server: - BBVERSIONS = "1.0.[0-6]:1.0.0+ \ 1.0.[7-9]:1.0.7+" + BBVERSIONS = "1.0.[0-6]:1.0.0+ \ 1.0.[7-9]:1.0.7+" SRC_URI_append_1.0.7+ = "file://some_patch_which_the_new_versions_need.patch;patch=1" - Note that the name of the range will default to the original + Note that the name of the range will default to the original version of the recipe, so given OE, a recipe file of - foo_1.0.0+.bb will default the name of its versions to - 1.0.0+. - This is useful, as the range name is not only placed into - overrides; it's also made available for the metadata to use in + foo_1.0.0+.bb will default the name of its versions to + 1.0.0+. + This is useful, as the range name is not only placed into + overrides; it's also made available for the metadata to use in the form of the - BPV - variable, for use in file:// search paths + BPV + variable, for use in file:// search paths (FILESPATH).
- +
Dependencies
Dependencies BitBake handles dependencies at the task level since to allow for - efficient operation with multiple processes executing in + efficient operation with multiple processes executing in parallel, a robust method of specifying task dependencies is needed.
- +
Dependencies Internal to the .bb File Where the dependencies are internal to a given .bb file, the @@ -965,12 +955,12 @@ There are also other events that occur based on specific requests to the server: directive.
- +
Build Dependencies DEPENDS lists build time dependencies. - The 'deptask' flag for tasks is used to signify the task of - each item listed in DEPENDS which must have completed before + The 'deptask' flag for tasks is used to signify the task of + each item listed in DEPENDS which must have completed before that task can be executed. @@ -979,29 +969,29 @@ There are also other events that occur based on specific requests to the server: - means the do_populate_staging task of each item in DEPENDS must + means the do_populate_staging task of each item in DEPENDS must have completed before do_configure can execute.
- +
Runtime Dependencies - The PACKAGES variable lists runtime packages and each of these + The PACKAGES variable lists runtime packages and each of these can have RDEPENDS and RRECOMMENDS runtime dependencies. The 'rdeptask' flag for tasks is used to signify the task of each item runtime dependency which must have completed before that task can be executed. - do_package_write[rdeptask] = + do_package_write[rdeptask] = "do_package" - means the do_package task of each item in RDEPENDS must have + means the do_package task of each item in RDEPENDS must have completed before do_package_write can execute.
- +
Recursive Dependencies These are specified with the 'recrdeptask' flag which is used @@ -1014,30 +1004,30 @@ There are also other events that occur based on specific requests to the server: and so on. It may be desireable to recurse not just through the dependencies - of those tasks but through the build and runtime dependencies + of those tasks but through the build and runtime dependencies of dependent tasks too. - If that is the case, the taskname itself should be referenced + If that is the case, the taskname itself should be referenced in the task list, e.g. do_a[recrdeptask] = "do_a do_b".
- +
Inter Task Dependencies - The 'depends' flag for tasks is a more generic form which allows - an interdependency on specific tasks rather than specifying + The 'depends' flag for tasks is a more generic form which allows + an interdependency on specific tasks rather than specifying the data in DEPENDS. - do_patch[depends] = + do_patch[depends] = "quilt-native:do_populate_staging" - means the do_populate_staging task of the target + means the do_populate_staging task of the target quilt-native must have completed before the do_patch can execute. - The 'rdepends' flag works in a similar way but takes targets in - the runtime namespace instead of the build time dependency + The 'rdepends' flag works in a similar way but takes targets in + the runtime namespace instead of the build time dependency namespace.
@@ -1045,106 +1035,106 @@ There are also other events that occur based on specific requests to the server:
Accessing Variable and the Data Store from Python - + NOTE: This section is in draft. - + It is often necessary to manipulate variables within python functions and the Bitbake data store has an API which allows this. The operations available are: - + d.getVar("X", expand=False) - + returns the value of variable "X", expanding the value if specified - + d.setVar("X", value) - + sets the value of "X" to value - + d.appendVar("X", value) - + adds value to the end of variable X - + d.prependVar("X", value) - + adds value to the start of variable X - + d.delVar("X") - + deletes the variable X from the data store - + d.renameVar("X", "Y") - + renames variable X to Y - - + + d.getVarFlag("X", flag, expand=False) - + gets given flag from variable X but does not expand it. - + d.setVarFlag("X", flag, value) - + sets given flag for variable X to value. Note, setVarFlags will not clear previous flags. Think of this method as addVarFlags. - + d.appendVarFlag("X", flag, value) - + d.prependVarFlag("X", flag, value) - + d.delVarFlag("X", flag) - + d.setVarFlags("X", flagsdict) - + sets the flags specified in the dict() parameter - + d.getVarFlags("X") - + returns a dict of the flags for X - + d.delVarFlags - + deletes all the flags for a variable - +
- \ No newline at end of file + -- cgit 1.2.3-korg