Android and PTT

這個標題有點奇怪, 這兩個東西怎麼會有關系,
裡面甚至沒有一個字母是一樣的, 客官請聽我慢慢說來, 這是個有趣的故事,

上個月我寫了一篇Android porting Experience的文章,
其實純粹是紀錄自己porting的過程, 方便自己也方便別人查詢, 算是個經驗交流,
沒想到過了幾天居然有人在我另一篇blog留下了下面的言論.


這位網友實在是太可愛了 XD
所以我就跟他說可以email問我問題,
我們也交換了gmail, 後來gtalk了幾次,
雖然不知道我的談話有沒有解答他的疑惑,
但是他很信守承諾的給了我1688的Ptt幣,
下面是真相, 網友帳號我mark起來幫他保密 :)


我的帳號就從經濟裝況"赤貧"變成了這個樣子


從學生時代就接過不少case, 其中交易自然都是現金為主,
也做過一些open source的東西, 那就是大家興趣交流交流, 跟錢無關,
沒想到這次居然是用Ptt幣來做交換 XD
這樣我又有P幣可以去賭博了...科科

Android Porting Experience

Recently, I have spent 3 working days on porting Android to our PXA270 HW platform
Brief Condition:
HW:
PXA270 with PCI and IDE support
SW:
Linux 2.6.21 source code with our own driver (for PCI & IDE)
Linux 2.6.23 source code with android patch

Method:
1. porting customized driver from 2.6.21 to 2.6.23
2. porting android patch to 2.6.21

First of all, I must to explain what Android Kernel require.
1. EABI support
config:
CONFIG_AEABI=y
2. Thumb support
config:
CONFIG_ARM_THUMB=y
3. OpenBinder (from PalmSource)
file:
drivers/binder, include/linux/binder*
config: CONFIG_BINDER
4. Android Special Device
file:
drivers/android, include/linux/android*
config:
CONFIG_ANDROID_POWER
CONFIG_ANDROID_POWER_STAT
CONFIG_ANDROID_LOGGER

It looks like porting android patch into 2.6.21 is more simple. Therefore, I decide to use the second method. After porting drivers/android/*, EABI and Thumb. I can see a red-dot on the screen. Then I start to porting the openbinder to get into the Android desktop.

There are a lot of web pages talking about porting the Android binary into ARM platform. The steps is copy system/, data/, etc/, /init. And Writing a startup script to start Android. You can find these information in http://benno.id.au/blog/, http://nemustech.blogspot.com/2007/12/android-porting-to-real-target-hw.html. After I do all of this, the android still block in

clock_gettime(CLOCK_MONOTONIC, {127, 101400000}) = 0
clock_gettime(CLOCK_MONOTONIC, {127, 103070000}) = 0
clock_gettime(CLOCK_MONOTONIC, {127, 104026000}) = 0
futex(0x134ac, FUTEX_WAIT, -1, {4, 997000000}) = 0
Finally, I found that my rootfs is jffs2, but jffs2 can't support mmap and /init will be failed. I put everything into the IDE hard disk and format as ext2 and BINGO!!!!!
Here is a very useful reference discuss.

http://groups.google.com/group/android-internals/browse_thread/thread/93570c41bce07f16