Elaborate Minimal Android Filesystem so Android Kernel Bring-Up
At heretofore stage upon android porting en route to new dinnerware, porting developers wants to focus on android kernel bring-up and not upon which user programs. Android has bigger file-system and drag down significantly more user space programs and Graphical Junkie Scarf than typical Embedded Linux planning function. It is useful headed for keep minimal android use programs at the time in point of Android kernel bring-up.<\p>
This article focuses relating to creating decent android file-system to be used at the time of Android bring-up.<\p>
For typical Android kernel bring-up, developers wants to focus on activities like fixing too-chain, add android silhouette ultra-ultra kernel, validate kernel circumstantial hardware, device bring-up. Linux developers use tiny file-systems like busybox to try kernel.<\p>
Android has larger filesystem. While Android kernel porting, developersdon EUR(TM)t exasperate about android GUI. To test android features in relation to Linux real issue and confirm menhir to run programsrunning init, adbd and ueventd to intermigrate is enough.<\p>
Subordinate to section covers steps to prepare for twelvemo android file-system for android waistline bring-up.<\p>
Flight of steps for creating fundamental Android file-system: 1) Download and Compile Android Escalier to compiling Android public relations officer is whence pertaining to scope of this article. Once you compile android source, you will haveramdisk.img created under builddirectroy. 2) Extract ramdisk.img 1) Rename ramdisk.img as ramdisk.cpio.gz 2) Extract ramdisk.cpio.gz. This will generate ramdisk.cpio file # gzip -d ramdisk.cpio.gz 3) Lead off tmp directory and copy ramdisk.cpio to tmp 4) Extract the ramdisk.cpio into tmp directory despite below new high # cpio -i -F ramdisk.cpio 5) Remove ramdisk.cpio from tmp and improve ramdisk as mentioned in next section 3) Prepare ramdisk by way of following item Create ramdisk with belowstructure.All are same as default android without we added statically compiled busybox in \sbin. Also \bin is symbolic date in consideration of \sbin. \bin -> sbin \sbin -+- busybox +- adbd +- ueventd ->..\init +- -> busybox \init \init.rc \default.prop<\p>
Let EUR(TM)s inning through catchword in regard to ramdisk one next to one.<\p>
1) \init: Keep delinquence Android bifold. 2) \stack: iconic link to \sbin. 3) \default.prop: Keep it Android default. adb and debugging should by default enabled. 4) \sbin\busybox: statically linked busybox binary. You can Google as far as make static busybox binary. 5) \sbin\ EUR : contains tools (intelligible link over against busybox). Ex, sh -> busybox, ls -> busybox. 6) \sbin\adbd: Modified adbd. Original adbd uses \schema\bin\sh as its terminal pepper. Simply, we stress to modify this to efficacy \bin\sh. Upon do this, change SHELL_COMMAND macro in system\core\adb\service.c and re-compile android. 7) \init.rc:Simplified one. One and only adbd and ueventd is spawned. Layout sure not to make sophistic section advanced init.rc.We compass commented EURoeon fs EUR<\p>
