diff options
Diffstat (limited to 'documentation/dev-manual/dev-manual-newbie.xml')
-rw-r--r-- | documentation/dev-manual/dev-manual-newbie.xml | 269 |
1 files changed, 3 insertions, 266 deletions
diff --git a/documentation/dev-manual/dev-manual-newbie.xml b/documentation/dev-manual/dev-manual-newbie.xml index c2147b39e7..97e2590763 100644 --- a/documentation/dev-manual/dev-manual-newbie.xml +++ b/documentation/dev-manual/dev-manual-newbie.xml | |||
@@ -167,7 +167,7 @@ | |||
167 | with the OpenEmbedded build system is advisable. | 167 | with the OpenEmbedded build system is advisable. |
168 | Of the SCMs BitBake supports, the | 168 | Of the SCMs BitBake supports, the |
169 | Yocto Project team strongly recommends using | 169 | Yocto Project team strongly recommends using |
170 | <link linkend='git'>Git</link>. | 170 | <ulink url='&YOCTO_DOCS_REF_URL;#git'>Git</ulink>. |
171 | Git is a distributed system that is easy to backup, | 171 | Git is a distributed system that is easy to backup, |
172 | allows you to work remotely, and then connects back to the | 172 | allows you to work remotely, and then connects back to the |
173 | infrastructure. | 173 | infrastructure. |
@@ -306,7 +306,7 @@ | |||
306 | This section summarizes the key recommendations described in the | 306 | This section summarizes the key recommendations described in the |
307 | previous sections: | 307 | previous sections: |
308 | <itemizedlist> | 308 | <itemizedlist> |
309 | <listitem><para>Use <link linkend='git'>Git</link> | 309 | <listitem><para>Use <ulink url='&YOCTO_DOCS_REF_URL;#git'>Git</ulink> |
310 | as the source control system.</para></listitem> | 310 | as the source control system.</para></listitem> |
311 | <listitem><para>Maintain your Metadata in layers that make sense | 311 | <listitem><para>Maintain your Metadata in layers that make sense |
312 | for your situation. | 312 | for your situation. |
@@ -354,269 +354,6 @@ | |||
354 | </section> | 354 | </section> |
355 | </section> | 355 | </section> |
356 | 356 | ||
357 | <section id='git'> | ||
358 | <title>Git</title> | ||
359 | |||
360 | <para> | ||
361 | The Yocto Project makes extensive use of Git, | ||
362 | which is a free, open source distributed version control system. | ||
363 | Git supports distributed development, non-linear development, and can handle large projects. | ||
364 | It is best that you have some fundamental understanding of how Git tracks projects and | ||
365 | how to work with Git if you are going to use the Yocto Project for development. | ||
366 | This section provides a quick overview of how Git works and provides you with a summary | ||
367 | of some essential Git commands. | ||
368 | </para> | ||
369 | |||
370 | <para> | ||
371 | For more information on Git, see | ||
372 | <ulink url='http://git-scm.com/documentation'></ulink>. | ||
373 | If you need to download Git, go to <ulink url='http://git-scm.com/download'></ulink>. | ||
374 | </para> | ||
375 | |||
376 | <section id='repositories-tags-and-branches'> | ||
377 | <title>Repositories, Tags, and Branches</title> | ||
378 | |||
379 | <para> | ||
380 | As mentioned earlier in the section | ||
381 | "<ulink url='&YOCTO_DOCS_REF_URL;#yocto-project-repositories'>Yocto Project Source Repositories</ulink>", | ||
382 | the Yocto Project maintains source repositories at | ||
383 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink>. | ||
384 | If you look at this web-interface of the repositories, each item is a separate | ||
385 | Git repository. | ||
386 | </para> | ||
387 | |||
388 | <para> | ||
389 | Git repositories use branching techniques that track content change (not files) | ||
390 | within a project (e.g. a new feature or updated documentation). | ||
391 | Creating a tree-like structure based on project divergence allows for excellent historical | ||
392 | information over the life of a project. | ||
393 | This methodology also allows for an environment from which you can do lots of | ||
394 | local experimentation on projects as you develop changes or new features. | ||
395 | </para> | ||
396 | |||
397 | <para> | ||
398 | A Git repository represents all development efforts for a given project. | ||
399 | For example, the Git repository <filename>poky</filename> contains all changes | ||
400 | and developments for Poky over the course of its entire life. | ||
401 | That means that all changes that make up all releases are captured. | ||
402 | The repository maintains a complete history of changes. | ||
403 | </para> | ||
404 | |||
405 | <para> | ||
406 | You can create a local copy of any repository by "cloning" it with the Git | ||
407 | <filename>clone</filename> command. | ||
408 | When you clone a Git repository, you end up with an identical copy of the | ||
409 | repository on your development system. | ||
410 | Once you have a local copy of a repository, you can take steps to develop locally. | ||
411 | For examples on how to clone Git repositories, see the | ||
412 | "<link linkend='getting-setup'>Getting Set Up</link>" section. | ||
413 | </para> | ||
414 | |||
415 | <para> | ||
416 | It is important to understand that Git tracks content change and | ||
417 | not files. | ||
418 | Git uses "branches" to organize different development efforts. | ||
419 | For example, the <filename>poky</filename> repository has | ||
420 | several branches that include the current | ||
421 | <filename>&DISTRO_NAME_NO_CAP;</filename> branch, the | ||
422 | <filename>master</filename> branch, and many branches for past | ||
423 | Yocto Project releases. | ||
424 | You can see all the branches by going to | ||
425 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi/poky/'></ulink> and | ||
426 | clicking on the | ||
427 | <filename><ulink url='&YOCTO_GIT_URL;/cgit.cgi/poky/refs/heads'>[...]</ulink></filename> | ||
428 | link beneath the "Branch" heading. | ||
429 | </para> | ||
430 | |||
431 | <para> | ||
432 | Each of these branches represents a specific area of development. | ||
433 | The <filename>master</filename> branch represents the current or most recent | ||
434 | development. | ||
435 | All other branches represent offshoots of the <filename>master</filename> | ||
436 | branch. | ||
437 | </para> | ||
438 | |||
439 | <para> | ||
440 | When you create a local copy of a Git repository, the copy has the same set | ||
441 | of branches as the original. | ||
442 | This means you can use Git to create a local working area (also called a branch) | ||
443 | that tracks a specific development branch from the source Git repository. | ||
444 | in other words, you can define your local Git environment to work on any development | ||
445 | branch in the repository. | ||
446 | To help illustrate, here is a set of commands that creates a local copy of the | ||
447 | <filename>poky</filename> Git repository and then creates and checks out a local | ||
448 | Git branch that tracks the Yocto Project &DISTRO; Release (&DISTRO_NAME;) development: | ||
449 | <literallayout class='monospaced'> | ||
450 | $ cd ~ | ||
451 | $ git clone git://git.yoctoproject.org/poky | ||
452 | $ cd poky | ||
453 | $ git checkout -b &DISTRO_NAME_NO_CAP; origin/&DISTRO_NAME_NO_CAP; | ||
454 | </literallayout> | ||
455 | In this example, the name of the top-level directory of your local | ||
456 | <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> | ||
457 | is "poky" and the name of that local working area (local branch) | ||
458 | you just created and checked out is "&DISTRO_NAME_NO_CAP;". | ||
459 | The files in your local repository now reflect the same files that | ||
460 | are in the "&DISTRO_NAME_NO_CAP;" development branch of the | ||
461 | Yocto Project's "poky" upstream repository. | ||
462 | It is important to understand that when you create and checkout a | ||
463 | local working branch based on a branch name, | ||
464 | your local environment matches the "tip" of that development branch | ||
465 | at the time you created your local branch, which could be | ||
466 | different from the files at the time of a similarly named release. | ||
467 | In other words, creating and checking out a local branch based on | ||
468 | the "&DISTRO_NAME_NO_CAP;" branch name is not the same as | ||
469 | cloning and checking out the "master" branch. | ||
470 | Keep reading to see how you create a local snapshot of a Yocto | ||
471 | Project Release. | ||
472 | </para> | ||
473 | |||
474 | <para> | ||
475 | Git uses "tags" to mark specific changes in a repository. | ||
476 | Typically, a tag is used to mark a special point such as the final | ||
477 | change before a project is released. | ||
478 | You can see the tags used with the <filename>poky</filename> Git | ||
479 | repository by going to | ||
480 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi/poky/'></ulink> and | ||
481 | clicking on the | ||
482 | <filename><ulink url='&YOCTO_GIT_URL;/cgit.cgi/poky/refs/tags'>[...]</ulink></filename> | ||
483 | link beneath the "Tag" heading. | ||
484 | </para> | ||
485 | |||
486 | <para> | ||
487 | Some key tags are | ||
488 | <filename>dizzy-12.0.0</filename>, | ||
489 | <filename>fido-13.0.0</filename>, | ||
490 | <filename>jethro-14.0.0</filename>, and | ||
491 | <filename>&DISTRO_NAME_NO_CAP;-&POKYVERSION;</filename>. | ||
492 | These tags represent Yocto Project releases. | ||
493 | </para> | ||
494 | |||
495 | <para> | ||
496 | When you create a local copy of the Git repository, you also have access to all the | ||
497 | tags. | ||
498 | Similar to branches, you can create and checkout a local working Git branch based | ||
499 | on a tag name. | ||
500 | When you do this, you get a snapshot of the Git repository that reflects | ||
501 | the state of the files when the change was made associated with that tag. | ||
502 | The most common use is to checkout a working branch that matches a specific | ||
503 | Yocto Project release. | ||
504 | Here is an example: | ||
505 | <literallayout class='monospaced'> | ||
506 | $ cd ~ | ||
507 | $ git clone git://git.yoctoproject.org/poky | ||
508 | $ cd poky | ||
509 | $ git checkout -b my-&DISTRO_NAME_NO_CAP;-&POKYVERSION; &DISTRO_NAME_NO_CAP;-&POKYVERSION; | ||
510 | </literallayout> | ||
511 | In this example, the name of the top-level directory of your local Yocto Project | ||
512 | Files Git repository is <filename>poky</filename>. | ||
513 | And, the name of the local branch you have created and checked out is | ||
514 | <filename>my-&DISTRO_NAME_NO_CAP;-&POKYVERSION;</filename>. | ||
515 | The files in your repository now exactly match the Yocto Project &DISTRO; | ||
516 | Release tag (<filename>&DISTRO_NAME_NO_CAP;-&POKYVERSION;</filename>). | ||
517 | It is important to understand that when you create and checkout a local | ||
518 | working branch based on a tag, your environment matches a specific point | ||
519 | in time and not the entire development branch. | ||
520 | </para> | ||
521 | </section> | ||
522 | |||
523 | <section id='basic-commands'> | ||
524 | <title>Basic Commands</title> | ||
525 | |||
526 | <para> | ||
527 | Git has an extensive set of commands that lets you manage changes and perform | ||
528 | collaboration over the life of a project. | ||
529 | Conveniently though, you can manage with a small set of basic operations and workflows | ||
530 | once you understand the basic philosophy behind Git. | ||
531 | You do not have to be an expert in Git to be functional. | ||
532 | A good place to look for instruction on a minimal set of Git commands is | ||
533 | <ulink url='http://git-scm.com/documentation'>here</ulink>. | ||
534 | If you need to download Git, you can do so | ||
535 | <ulink url='http://git-scm.com/download'>here</ulink>, although | ||
536 | any reasonably current Linux distribution should already have an | ||
537 | installable package for Git. | ||
538 | </para> | ||
539 | |||
540 | <para> | ||
541 | If you do not know much about Git, you should educate | ||
542 | yourself by visiting the links previously mentioned. | ||
543 | </para> | ||
544 | |||
545 | <para> | ||
546 | The following list briefly describes some basic Git operations as a way to get started. | ||
547 | As with any set of commands, this list (in most cases) simply shows the base command and | ||
548 | omits the many arguments they support. | ||
549 | See the Git documentation for complete descriptions and strategies on how to use these commands: | ||
550 | <itemizedlist> | ||
551 | <listitem><para><emphasis><filename>git init</filename>:</emphasis> Initializes an empty Git repository. | ||
552 | You cannot use Git commands unless you have a <filename>.git</filename> repository.</para></listitem> | ||
553 | <listitem><para><emphasis><filename>git clone</filename>:</emphasis> | ||
554 | Creates a local clone of a Git repository. | ||
555 | During collaboration, this command allows you to create a | ||
556 | local Git repository that is on equal footing with a fellow | ||
557 | developer’s Git repository. | ||
558 | </para></listitem> | ||
559 | <listitem><para><emphasis><filename>git add</filename>:</emphasis> Stages updated file contents | ||
560 | to the index that | ||
561 | Git uses to track changes. | ||
562 | You must stage all files that have changed before you can commit them.</para></listitem> | ||
563 | <listitem><para><emphasis><filename>git commit</filename>:</emphasis> Creates a "commit" that documents | ||
564 | the changes you made. | ||
565 | Commits are used for historical purposes, for determining if a maintainer of a project | ||
566 | will allow the change, and for ultimately pushing the change from your local Git repository | ||
567 | into the project’s upstream (or master) repository.</para></listitem> | ||
568 | <listitem><para><emphasis><filename>git status</filename>:</emphasis> Reports any modified files that | ||
569 | possibly need to be staged and committed.</para></listitem> | ||
570 | <listitem><para><emphasis><filename>git checkout</filename> <replaceable>branch-name</replaceable>:</emphasis> Changes | ||
571 | your working branch. | ||
572 | This command is analogous to "cd".</para></listitem> | ||
573 | <listitem><para><emphasis><filename>git checkout –b</filename> <replaceable>working-branch</replaceable>:</emphasis> Creates | ||
574 | a working branch on your local machine where you can isolate work. | ||
575 | It is a good idea to use local branches when adding specific features or changes. | ||
576 | This way if you do not like what you have done you can easily get rid of the work.</para></listitem> | ||
577 | <listitem><para><emphasis><filename>git branch</filename>:</emphasis> Reports | ||
578 | existing local branches and | ||
579 | tells you the branch in which you are currently working.</para></listitem> | ||
580 | <listitem><para><emphasis><filename>git branch -D</filename> <replaceable>branch-name</replaceable>:</emphasis> | ||
581 | Deletes an existing local branch. | ||
582 | You need to be in a local branch other than the one you are deleting | ||
583 | in order to delete <replaceable>branch-name</replaceable>.</para></listitem> | ||
584 | <listitem><para><emphasis><filename>git pull</filename>:</emphasis> Retrieves information | ||
585 | from an upstream Git | ||
586 | repository and places it in your local Git repository. | ||
587 | You use this command to make sure you are synchronized with the repository | ||
588 | from which you are basing changes (.e.g. the master branch).</para></listitem> | ||
589 | <listitem><para><emphasis><filename>git push</filename>:</emphasis> | ||
590 | Sends all your committed local changes to an upstream Git | ||
591 | repository (e.g. a contribution repository). | ||
592 | The maintainer of the project draws from these repositories | ||
593 | when adding changes to the project’s master repository or | ||
594 | other development branch. | ||
595 | </para></listitem> | ||
596 | <listitem><para><emphasis><filename>git merge</filename>:</emphasis> Combines or adds changes from one | ||
597 | local branch of your repository with another branch. | ||
598 | When you create a local Git repository, the default branch is named "master". | ||
599 | A typical workflow is to create a temporary branch for isolated work, make and commit your | ||
600 | changes, switch to your local master branch, merge the changes from the temporary branch into the | ||
601 | local master branch, and then delete the temporary branch.</para></listitem> | ||
602 | <listitem><para><emphasis><filename>git cherry-pick</filename>:</emphasis> Choose and apply specific | ||
603 | commits from one branch into another branch. | ||
604 | There are times when you might not be able to merge all the changes in one branch with | ||
605 | another but need to pick out certain ones.</para></listitem> | ||
606 | <listitem><para><emphasis><filename>gitk</filename>:</emphasis> Provides a GUI view of the branches | ||
607 | and changes in your local Git repository. | ||
608 | This command is a good way to graphically see where things have diverged in your | ||
609 | local repository.</para></listitem> | ||
610 | <listitem><para><emphasis><filename>git log</filename>:</emphasis> Reports a history of your changes to the | ||
611 | repository.</para></listitem> | ||
612 | <listitem><para><emphasis><filename>git diff</filename>:</emphasis> Displays line-by-line differences | ||
613 | between your local working files and the same files in the upstream Git repository that your | ||
614 | branch currently tracks.</para></listitem> | ||
615 | </itemizedlist> | ||
616 | </para> | ||
617 | </section> | ||
618 | </section> | ||
619 | |||
620 | <section id='submitting-a-defect-against-the-yocto-project'> | 357 | <section id='submitting-a-defect-against-the-yocto-project'> |
621 | <title>Submitting a Defect Against the Yocto Project</title> | 358 | <title>Submitting a Defect Against the Yocto Project</title> |
622 | 359 | ||
@@ -862,7 +599,7 @@ | |||
862 | </para></listitem> | 599 | </para></listitem> |
863 | <listitem><para> | 600 | <listitem><para> |
864 | <emphasis>Search by File:</emphasis> | 601 | <emphasis>Search by File:</emphasis> |
865 | Using <link linkend='git'>Git</link>, you can enter the | 602 | Using <ulink url='&YOCTO_DOCS_REF_URL;#git'>Git</ulink>, you can enter the |
866 | following command to bring up a short list of all commits | 603 | following command to bring up a short list of all commits |
867 | against a specific file: | 604 | against a specific file: |
868 | <literallayout class='monospaced'> | 605 | <literallayout class='monospaced'> |