sehrich的专栏

<br />screen coordinate(Xs) VS device coordinate(Xd)<br />screen coordinate is related to screen rotation, which could be change after orietation. But device coordinate is fixed, left up is original point.<br /> <br />Xs= Xd*A+Yd*B+C<br />Ys= Yd*D+Yd*E

Phenomenon:Some internal or external DMA controllerhas address limitation, for example, which could only access lower 128MBphysical memory. While not all driver will alloc proper physical memory to meetthis limitation. How could Linux kernel do then?

Previously we looked at how the kernel managesvirtual memory for a user process, but files and I/O were left out. Thispost covers the important and often misunderstood relationship between filesand memory and its consequences for performance.Two se

hwclock --systohc: sync hardware time to system timehwclock --hctosys: sync system time to hardware time

Android 4.0(ICS) merge handset and tablet UI together, make customer flexible to use which UI they want. On marketing nowdays, phone use phone mode directly and other product like tablet/MID/PND use t

编译Linux下的库是一件痛苦的事情，这里主要阐述glib和wpa_supplicant库的编译，因各自的依赖关系，另外一些库要事先编译。glib依赖libffi和zlib，而wpa_supplicant依赖dbus和openssl。总结下交叉编译几个常见的逻辑：1. 指定CC为交叉编译器2. 指定--prefix，如果不指定，会将宿主机PC上相应的库给覆盖了，如果是系统关键的