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author | Patrick Georgi <pgeorgi@google.com> | 2019-09-15 18:21:25 +0200 |
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committer | Patrick Georgi <pgeorgi@google.com> | 2019-09-16 21:17:33 +0000 |
commit | 3c599a2c086a5405a1997de65de1aacc988e7823 (patch) | |
tree | d1d2f27b035576bce2ef59ec12c9b32a718b628f /Documentation/tutorial | |
parent | de2b6b834984f69dad19dc9d0726a3f6851be2eb (diff) | |
download | coreboot-3c599a2c086a5405a1997de65de1aacc988e7823.tar.xz |
Documentation: rename "Rookie guide" to "tutorial"
We generally try to stay away from ascribing attributes to (future)
devs. "Rookie guide" refers to the reader, while "tutorial" refers
to the material.
In the same spirit, move from "lessons" to "parts". It's not school :-)
Change-Id: I11a69a2a05ba9a0bc48f8bf62463d9585da043ec
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35425
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lance Zhao <lance.zhao@gmail.com>
Reviewed-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Diffstat (limited to 'Documentation/tutorial')
-rw-r--r-- | Documentation/tutorial/index.md | 4 | ||||
-rw-r--r-- | Documentation/tutorial/part1.md | 169 | ||||
-rw-r--r-- | Documentation/tutorial/part2.md | 305 |
3 files changed, 478 insertions, 0 deletions
diff --git a/Documentation/tutorial/index.md b/Documentation/tutorial/index.md new file mode 100644 index 0000000000..48dfbe5da6 --- /dev/null +++ b/Documentation/tutorial/index.md @@ -0,0 +1,4 @@ +# Tutorial + +* [Part 1: Starting from scratch](part1.md) +* [Part 2: Submitting a patch to coreboot.org](part2.md) diff --git a/Documentation/tutorial/part1.md b/Documentation/tutorial/part1.md new file mode 100644 index 0000000000..75a9ba375f --- /dev/null +++ b/Documentation/tutorial/part1.md @@ -0,0 +1,169 @@ +Tutorial, part 1: Starting from scratch +=========================================== + +From a fresh Ubuntu 16.04 or 18.04 install, here are all the steps required for +a very basic build: + +Download, configure, and build coreboot +--------------------------------------- + +### Step 1 - Install tools and libraries needed for coreboot + $ sudo apt-get install -y bison build-essential curl flex git gnat libncurses5-dev m4 zlib1g-dev + +### Step 2 - Download coreboot source tree + $ git clone https://review.coreboot.org/coreboot + $ cd coreboot + +### Step 3 - Build the coreboot toolchain +Please note that this can take a significant amount of time + + $ make crossgcc-i386 CPUS=$(nproc) + +Also note that you can possibly use your system toolchain, but the results are +not reproducible, and may have issues, so this is not recommended. See step 5 +to use your system toolchain. + +### Step 4 - Build the payload - coreinfo + $ make -C payloads/coreinfo olddefconfig + $ make -C payloads/coreinfo + +### Step 5 - Configure the build + +##### Configure your mainboard + $ make menuconfig + select 'Mainboard' menu + Beside 'Mainboard vendor' should be '(Emulation)' + Beside 'Mainboard model' should be 'QEMU x86 i440fx/piix4' + select < Exit > +These should be the default selections, so if anything else was set, run +`make distclean` to remove your old config file and start over. + +##### Optionally use your system toolchain (Again, not recommended) + select 'General Setup' menu + select 'Allow building with any toolchain' + select < Exit > + +##### Select the payload + select 'Payload' menu + select 'Add a Payload' + choose 'An Elf executable payload' + select 'Payload path and filename' + enter 'payloads/coreinfo/build/coreinfo.elf' + select < Exit > + select < Exit > + select < Yes > + +##### check your configuration (optional step): + + $ make savedefconfig + $ cat defconfig + +There should only be two lines (or 3 if you're using the system toolchain): + + CONFIG_PAYLOAD_ELF=y + CONFIG_PAYLOAD_FILE="payloads/coreinfo/build/coreinfo.elf" + +### Step 6 - build coreboot + $ make + +At the end of the build, you should see: + + Build emulation/qemu-i440fx (QEMU x86 i440fx/piix4) + +This means your build was successful. The output from the build is in the build +directory. build/coreboot.rom is the full rom file. + +Test the image using QEMU +------------------------- + +### Step 7 - Install QEMU + $ sudo apt-get install -y qemu + +### Step 8 - Run QEMU +Start QEMU, and point it to the ROM you just built: + + $ qemu-system-x86_64 -bios build/coreboot.rom -serial stdio + +You should see the serial output of coreboot in the original console window, and +a new window will appear running the coreinfo payload. + +Summary +------- + +### Step 1 summary - Install tools and libraries needed for coreboot +You installed the minimum additional requirements for ubuntu to download and +build coreboot. Ubuntu already has most of the other tools that would be +required installed by default. + +* `build-essential` is the basic tools for doing builds. It comes pre-installed +on some Ubuntu flavors, and not on others. +* `git` is needed to download coreboot from the coreboot git repository. +* `libncurses5-dev` is needed to build the menu for 'make menuconfig' +* `m4, bison, curl, flex, zlib1g-dev, gcc, gnat` and `g++` or `clang` +are needed to build the coreboot toolchain. `gcc` and `gnat` have to be +of the same version. + +If you started with a different distribution, you might need to install many +other items which vary by distribution. + +### Step 2 summary - Download coreboot source tree +This will download a 'read-only' copy of the coreboot tree. This just means +that if you made changes to the coreboot tree, you couldn't immediately +contribute them back to the community. To pull a copy of coreboot that would +allow you to contribute back, you would first need to sign up for an account on +gerrit. + +### Step 3 summary - Build the coreboot toolchain. +This builds one of the coreboot cross-compiler toolchains for X86 platforms. +Because of the variability of compilers and the other required tools between +the various operating systems that coreboot can be built on, coreboot supplies +and uses its own cross-compiler toolchain to build the binaries that end up as +part of the coreboot ROM. The toolchain provided by the operating system (the +'host toolchain') is used to build various tools that will run on the local +system during the build process. + +### Step 4 summary - Build the payload +To actually do anything useful with coreboot, you need to build a payload to +include in the rom. The idea behind coreboot is that it does the minimum amount +possible before passing control of the machine to a payload. There are various +payloads such as grub or SeaBIOS that are typically used to boot the operating +system. Instead, we used coreinfo, a small demonstration payload that allows the +user to look at various things such as memory and the contents of coreboot's +cbfs - the pieces that make up the coreboot rom. + +### Step 5 summary - Configure the build +This step configures coreboot's build options using the menuconfig interface to +Kconfig. Kconfig is the same configuration program used by the linux kernel. It +allows you to enable, disable, and change various values to control the coreboot +build process, including which mainboard(motherboard) to use, which toolchain to +use, and how the runtime debug console should be presented and saved. +Anytime you change mainboards in Kconfig, you should always run `make distclean` +before running `make menuconfig`. Due to the way that Kconfig works, values will +be kept from the previous mainboard if you skip the clean step. This leads to a +hybrid configuration which may or may not work as expected. + +### Step 6 summary - Build coreboot +You may notice that a number of other pieces are downloaded at the beginning of +the build process. These are the git submodules used in various coreboot builds. +By default, the _blobs_ submodule is not downloaded. This git submodule may be +required for other builds for microcode or other binaries. To enable downloading +this submodule, select the option "Allow use of binary-only repository" in the +"General Setup" menu of Kconfig +This attempts to build the coreboot rom. The rom file itself ends up in the +build directory as 'coreboot.rom'. At the end of the build process, the build +displayed the contents of the rom file. + +### Step 7 summary - Install QEMU +QEMU is a processor emulator which we can use to show coreboot + +### Step 8 summary - Run QEMU +Here's the command line broken down: +* `qemu-system-x86_64` +This starts the QEMU emulator with the i440FX host PCI bridge and PIIX3 PCI to +ISA bridge. +* `-bios build/coreboot.rom` +Use the bios rom image that we just built. If this is left off, the standard +SeaBIOS image that comes with QEMU is used. +* `-serial stdio` +Send the serial output to the console. This allows you to view the coreboot +debug output. diff --git a/Documentation/tutorial/part2.md b/Documentation/tutorial/part2.md new file mode 100644 index 0000000000..e5322186f9 --- /dev/null +++ b/Documentation/tutorial/part2.md @@ -0,0 +1,305 @@ +# Tutorial, part 2: Submitting a patch to coreboot.org + +## Part 1: Setting up an account at coreboot.org + +If you already have an account, skip to Part 2. + +Otherwise, go to <https://review.coreboot.org> in your preferred web browser. +Select **Sign in** in the upper right corner. + +Select the appropriate sign-in. For example, if you have a Google account, +select **Google OAuth2** (gerrit-oauth-provider plugin). **Note:** Your +username for the account will be the username of the account you used to +sign-in with. (ex. your Google username). + +## Part 2a: Set up RSA Private/Public Key + +If you prefer to use an HTTP password instead, skip to Part 2b. + +For the most up-to-date instructions on how to set up SSH keys with Gerrit go to +<https://gerrit-documentation.storage.googleapis.com/Documentation/2.14.2/user-upload.html#configure_ssh> +and follow the instructions there. Then, skip to Part 3. + +Additionally, that section of the Web site provides explanation on starting +an ssh-agent, which may be particularly helpful for those who anticipate +frequently uploading changes. + +If you instead prefer to have review.coreboot.org specific instructions, +follow the steps below. Note that this particular section may have the +most up-to-date instructions. + +If you do not have an RSA key set up on your account already (as is the case +with a newly created account), follow the instructions below; otherwise, +doing so could overwrite an existing key. + +In the upper right corner, select your name and click on **Settings**. +Select **SSH Public Keys** on the left-hand side. + +In a terminal, run `ssh-keygen` and confirm the default path `.ssh/id_rsa`. + +Make a passphrase -- remember this phrase. It will be needed whenever you use +this RSA Public Key. **Note:** You might want to use a short password, or +forego the password altogether as you will be using it very often. + +Open `id_rsa.pub`, copy all contents and paste into the textbox under +"Add SSH Public Key" in the https://review.coreboot.org webpage. + +## Part 2b: Setting up an HTTP Password + +Alternatively, instead of using SSH keys, you can use an HTTP password. To do so, +after you select your name and click on **Settings** on the left-hand side, rather +than selecting **SSH Public Keys**, select **HTTP Password**. + +Click **Generate Password**. This should fill the "Password" box with a password. Copy +the password, and add the following to your `$HOME/.netrc` file: + + machine review.coreboot.org login YourUserNameHere password YourPasswordHere + +where YourUserNameHere is your username, and YourPasswordHere is the password you +just generated. + +## Part 3: Clone coreboot and configure it for submitting patches + +On Gerrit, click on the **Browse** tab in the upper left corner and select +**Repositories**. From the listing, select the "coreboot" repo. You may have +to click the next page arrow at the bottom a few times to find it. + +If you are using SSH keys, select **ssh** from the tabs under "Project +coreboot" and run the "clone with commit-msg hook" command that's provided. +This should prompt you for your id_rsa passphrase, if you previously set one. + +**Note:** if the **ssh** option is not showing, check that you have a username +set. Click the profile picture at the top right and select **User Settings**, +then set your username in the **Profile** section. + +If you are using HTTP, instead, select **http** from the tabs under "Project coreboot" +and run the command that appears. + +Now is a good time to configure your global git identity, if you haven't +already. + + git config --global user.name "Your Name" + git config --global user.email "Your Email" + +Finally, enter the local git repository and set up repository specific hooks +and other configurations. + + cd coreboot + make gitconfig + +## Part 4: Submit a commit + +An easy first commit to make is fixing existing checkpatch errors and warnings +in the source files. To see errors that are already present, build the files in +the repository by running `make lint` in the coreboot directory. Alternatively, +if you want to run `make lint` on a specific directory, run: + + for file in $(git ls-files | grep <filepath>); do \ + util/lint/checkpatch.pl --file $file --terse; done + +where `filepath` is the filepath of the directory (ex. `src/cpu/amd/car`). + +Any changes made to files under the src directory are made locally, +and can be submitted for review. + +Once you finish making your desired changes, use the command line to stage +and submit your changes. An alternative and potentially easier way to stage +and submit commits is to use git cola, a graphical user interface for git. For +instructions on how to do so, skip to Part 4b. + +## Part 4a: Using the command line to stage and submit a commit + +To use the command line to stage a commit, run + + git add <filename> + +where `filename` is the name of your file. + +To commit the change, run + + git commit -s + +**Note:** The -s adds a signed-off-by line by the committer. Your commit should be +signed off with your name and email (i.e. **Your Name** **\<Your Email\>**, based on +what you set with git config earlier). + +Running git commit first checks for any errors and warnings using lint. If +there are any, you must go back and fix them before submitting your commit. +You can do so by making the necessary changes, and then staging your commit again. + +When there are no errors or warnings, your default text editor will open. +This is where you will write your commit message. + +The first line of your commit message is your commit summary. This is a brief +one-line description of what you changed in the files using the template +below: + + <filepath>: Short description + +For example, + + cpu/amd/pi/00630F01: Fix checkpatch warnings and errors + +**Note:** It is good practice to use present tense in your descriptions +and do not punctuate your summary. + +Then hit Enter. The next paragraph should be a more in-depth explanation of the +changes you've made to the files. Again, it is good practice to use present +tense. Ex. + + Fix space prohibited between function name and open parenthesis, + line over 80 characters, unnecessary braces for single statement blocks, + space required before open brace errors and warnings. + +When you have finished writing your commit message, save and exit the text +editor. You have finished committing your change. If, after submitting your +commit, you wish to make changes to it, running `git commit --amend` allows +you to take back your commit and amend it. + +When you are done with your commit, run `git push` to push your commit to +coreboot.org. **Note:** To submit as a draft, use +`git push origin HEAD:refs/drafts/master`. Submitting as a draft means that +your commit will be on coreboot.org, but is only visible to those you add +as reviewers. + +This has been a quick primer on how to submit a change to Gerrit for review +using git. You may wish to review the [Gerrit code review workflow +documentation](https://gerrit-review.googlesource.com/Documentation/intro-user.html#code-review), +especially if you plan to work on multiple changes at the same time. + +## Part 4b: Using git cola to stage and submit a commit + +If git cola is not installed on your machine, see +<https://git-cola.github.io/downloads.html> for download instructions. + +After making some edits to src files, rather than run `git add`, run +`git cola` from the command line. You should see all of the files +edited under "Modified". + +In the textbox labeled "Commit summary" provide a brief one-line +description of what you changed in the files according to the template +below: + + <filepath>: Short description + +For example, + + cpu/amd/pi/00630F01: Fix checkpatch warnings and errors + +**Note:** It is good practice to use present tense in your descriptions +and do not punctuate your short description. + +In the larger text box labeled 'Extended description...' provide a more +in-depth explanation of the changes you've made to the files. Again, it +is good practice to use present tense. Ex. + + Fix space prohibited between function name and open parenthesis, + line over 80 characters, unnecessary braces for single statement blocks, + space required before open brace errors and warnings. + +Then press Enter two times to move the cursor to below your description. +To the left of the text boxes, there is an icon with an downward arrow. +Press the arrow and select "Sign Off." Make sure that you are signing off +with your name and email (i.e. **Your Name** **\<Your Email\>**, based on what +you set with git config earlier). + +Now, review each of your changes and mark either individual changes or +an entire file as Ready to Commit by marking it as 'Staged'. To do +this, select one file from the 'Modified' list. If you only want to +submit particular changes from each file, then highlight the red and +green lines for your changes, right click and select 'Stage Selected +Lines'. Alternatively, if an entire file is ready to be committed, just +double click on the file under 'Modified' and it will be marked as +Staged. + +Once the descriptions are done and all the edits you would like to +commit have been staged, press 'Commit' on the right of the text +boxes. + +If the commit fails due to persisting errors, a text box will appear +showing the errors. You can correct these errors within 'git cola' by +right-clicking on the file in which the error occurred and selecting +'Launch Diff Tool'. Make necessary corrections, close the Diff Tool and +'Stage' the corrected file again. It might be necessary to refresh +'git cola' in order for the file to be shown under 'Modified' again. +Note: Be sure to add any other changes that haven't already been +explained in the extended description. + +When ready, select 'Commit' again. Once all errors have been satisfied +and the commit succeeds, move to the command line and run `git push`. +**Note:** To submit as a draft, use `git push origin HEAD:refs/drafts/master`. +Submitting as a draft means that your commit will be on coreboot.org, but is +only visible to those you add as reviewers. + +## Part 5: Getting your commit reviewed + +Your commits can now be seen on review.coreboot.org if you select "Your" +and click on "Changes" and can be reviewed by others. Your code will +first be reviewed by build bot (Jenkins), which will either give you a warning +or verify a successful build; if so, your commit will receive a +1. Other +users may also give your commit +1. For a commit to be merged, it needs +to receive a +2. **Note:** A +1 and a +1 does not make a +2. Only certain users +can give a +2. + +## Part 6 (optional): bash-git-prompt + +To help make it easier to understand the state of the git repository +without running `git status` or `git log`, there is a way to make the +command line show the status of the repository at every point. This +is through bash-git-prompt. + +Instructions for installing this are found at: +<https://github.com/magicmonty/bash-git-prompt>. +**Note:** Feel free to search for different versions of git prompt, +as this one is specific to bash. + +Alternatively, follow the instructions below: +Run the following two commands in the command line: + + cd + git clone https://github.com/magicmonty/bash-git-prompt.git .bash-git-prompt --depth=1 + +**Note:** cd will change your directory to your home directory, so the +git clone command will be run there. + +Finally, open the `~/.bashrc` file and append the following two lines: + + GIT_PROMPT_ONLY_IN_REPO=1 + source ~/.bash-git-prompt/gitprompt.sh + +Now, whenever you are in a git repository, it will continuously display +its state. + +There also are additional configurations that you can change depending on your +preferences. If you wish to do so, look at the "All configs for .bashrc" section +on <https://github.com/magicmonty/bash-git-prompt>. Listed in that section are +various lines that you can copy, uncomment and add to your .bashrc file to +change the configurations. Example configurations include avoid fetching remote +status, and supporting versions of Git older than 1.7.10. + +## Appendix: Miscellaneous Advice + +### Updating a commit after running git push: + +Suppose you would like to update a commit that has already been pushed to the +remote repository. If the commit you wish to update is the most recent +commit you have made, after making your desired changes, stage the files +(either using git add or in git cola), and amend the commit. To do so, +if you are using the command line, run `git commit --amend`. If you are +using git cola, click on the gear icon located on the upper left side under +**Commit** and select **Amend Last Commit** in the drop down menu. Then, stage +the files you have changed, commit the changes, and run git push to push the +changes to the remote repository. Your change should be reflected in Gerrit as +a new patch set. + +If, however, the commit you wish to update is not the most recent commit you +have made, you will first need to checkout that commit. To do so, find the +URL of the commit on <https://review.coreboot.org> and go to that page; if +the commit is one that you previously pushed, it can be found by selecting +**My** and then **Changes** in the upper left corner. To checkout this commit, +in the upper right corner, click on **Download**, and copy the command listed +next to checkout by clicking **Copy to clipboard**. Then, run the copied +command in your coreboot repository. Now, the last commit should be the most +recent commit to that patch; to update it, make your desired changes, stage +the files, then amend and push the commit using the instructions in the above +paragraph. |