tag:blogger.com,1999:blog-55684832012-02-16T14:46:03.801+08:00Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.comBlogger91100tag:blogger.com,1999:blog-5568483.post-30064001191131060932011-06-19T22:05:00.001+08:002011-06-19T23:38:16.824+08:00

Working with source code buried in conditional macros(#if, #ifdef, #ifndef, ...) is sometimes really annoying, especially when we are trying to get the whole picture of what it does instead of every details in it. Simply expanding the conditionals with gcc -E usually doesn't help in this situation. Expansion of macros as well as the header files even makes the picture muddier. The unifdef(1)

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-69178402480876318892011-04-14T16:27:00.001+08:002011-04-14T16:31:21.837+08:00

Suppose we have a tarball containing a directory structure of root filesystem for an embedded device. ex: rootfs/ rootfs/init.rc rootfs/dev/... rootfs/etc/... rootfs/usr/... We'd like to extract the contained directory structure under the rootfs/ directly into the root directory of a mounted partition, for example, /mnt/sdb1. Otherwise, we will have to deal with the relocation of

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-2095906423739159282011-04-08T00:26:00.000+08:002011-04-08T00:26:06.974+08:00

[reference] https://bbs.archlinux.org/viewtopic.php?pid=909650 draugdel @ 2011-03-26 10:08:27 Error occurred while mounting usb stick via the device notifier org.freedesktop.UDisks.Error.PermissionDenied: Not Authorized Sol: Add a file named with .pkla suffix in /etc/polkit-1/localauthority/50-local.d/ ex: /etc/polkit-1/localauthority/50-local.d/mount.pkla and stuff the following contents

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-63065545497253161122011-03-20T03:17:00.002+08:002011-03-20T13:57:25.070+08:00

Check out this SlideShare Presentation: Introduction to Git BasicsView more presentations from Roy Lee.

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-69764501811422893292011-02-06T22:38:00.001+08:002011-02-06T22:42:24.861+08:00

The code flow of zygote initialization is rather complicated, especially when the JNIs are extensively involved. My IDE often fails to cross reference between them. So I log the code flow here and the location they are defined as well. In the very beginning, the init.rc initiated a Zygote process, which forks the SystemServer as we will see later. system/core/rootdir/init.rc service zygote /

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-50836217851629730422010-12-05T20:44:00.005+08:002010-12-08T00:22:46.516+08:00

Loopers, MessageQueues, and Handlers provide one of the facilities for processes and threads to communicate with each other. They are also one of the basis to implement the Services of Android framework. The relationship between these classes and how they interact with each other are not so easy to be seen through at the first glance. And that's why there are so many articles talking about them.

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-20015649348122874882010-06-20T15:21:00.003+08:002010-12-25T16:23:04.021+08:00

Reference: Java Native Interface: Programmer's Guide and Specification Edit HelloWorld.java HelloWorld.java class HelloWorld { private native void print(); public static void main(String[] args) { new HelloWorld().print(); } static { System.loadLibrary("HelloWorld"); } } Compile the JAVA class -- HelloWorld.class

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-61215221642002811462010-06-12T17:41:00.000+08:002010-06-13T01:13:19.552+08:00

We can dump the framebuffer of a android device and save it as a file on our host in one single step: $ adb pull /dev/graphics/fb0 fb.dump The dumped raw data is in RGB565 pixel format. So we'd like to convert it into a more common image format that could be recognized by common image viewers. And FFMPEG could be handy for doing the conversion like this: $ ffmpeg -f rawvideo -pix_fmt

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0tag:blogger.com,1999:blog-5568483.post-26380914122599567182010-06-12T11:31:00.000+08:002010-06-13T19:51:43.431+08:00

Earlier kernels export Rss and Vss of each single process to show how many page frames it occupies and how the address space it spans on a particular time. But this information is process-wide, and it doesn't help when you estimate system-wide memory usage. The problem is the lacking of information about how the processes share pages with each other. Simply summing up the Rss of all processes

Roy Leehttp://www.blogger.com/profile/07281846091489660503noreply@blogger.com0