如何让Buildroot 2015.08使用已有的Qt 5.2.1源码替代要求的5.5.0

Got it, let's walk through how to force Buildroot 2015.08 to use your locally available Qt 5.2.1 source instead of trying to download the required 5.5.0 version. Here's the step-by-step process:

Step 1: Locate the QtBase Package Config File #

First, navigate to the QtBase package directory in your Buildroot 2015.08 setup. You'll find the key configuration file here:

package/qt5/qtbase/qtbase.mk

This file controls everything related to downloading, verifying, and building QtBase for your target.

Step 2: Update Version and Source Filename #

Open qtbase.mk in a text editor and modify these variables:

• Change QTBASE_VERSION from 5.5.0 to 5.2.1
• Update QTBASE_SOURCE to match your local Qt 5.2.1 source archive name. For example:

  QTBASE_SOURCE = qtbase-opensource-src-5.2.1.tar.xz
  

Step 3: Fix the Source Checksum (Critical!) #

Buildroot verifies the integrity of source archives using checksums. You'll need to replace the existing checksum with the one from your local Qt 5.2.1 file:

1. Calculate the SHA256 checksum of your local archive with this command (run in the directory where your Qt source is stored):

   sha256sum qtbase-opensource-src-5.2.1.tar.xz
   

2. In qtbase.mk, find QTBASE_SHA256 and replace its value with the output from the command above.

Step 4: Point Buildroot to Your Local Source #

You have two options here to avoid network downloads:

• Option 1 (Simplest): Copy your Qt 5.2.1 source archive into Buildroot's dl/ directory. Buildroot automatically checks this directory first before attempting to download from the internet.
• Option 2 (More Flexible): Modify the QTBASE_SITE variable in qtbase.mk to point directly to your local directory. For example:

  QTBASE_SITE = file:///home/your-username/path-to-qt-sources/
  

Step 5: Handle Compatibility Differences #

Buildroot 2015.08's Qt 5.5.0 configuration might include options or dependencies that don't work with Qt 5.2.1. Here's how to address this:

• Check the QTBASE_CONF_OPTS section in qtbase.mk—remove any flags that are specific to Qt 5.5.0 (like newer feature toggles) and ensure all options are supported by Qt 5.2.1.
• If you're using other Qt components (like qtdeclarative, qtmultimedia), you'll need to update their respective .mk files in package/qt5/ to match Qt 5.2.1 versions, or disable them temporarily in make menuconfig if you don't need them.

Step 6: Reconfigure and Build #

1. Run make menuconfig to confirm QtBase is still selected under Target packages > Graphic libraries and applications > Qt5 > qtbase.
2. Start the build with make—if you hit compilation errors, they're likely due to configuration mismatches. Check the error logs carefully and adjust the qtbase.mk options or dependencies as needed.

Heads Up #

Keep in mind that Qt 5.2.1 is older than the version Buildroot 2015.08 expects, so you might run into minor compatibility issues with Buildroot's default configurations. Be prepared to tweak the build options or resolve dependency conflicts as they pop up.

内容的提问来源于stack exchange，提问作者mehmetfa