Fiddling

0. install git ($ sudo yum install git)
1. Download JDK 5.0 (jdk-1_5_0_19-linux-i586-rpm.bin) from sun

   $ cd /usr/local
   $ /tmp/jdk-1_5_0_19-linux-i586.bin 
   $ sudo updatedb
   $ locate javac | grep bin
   /usr/local/jdk1.5.0_19/bin/javac          (the result)
   $ sudo /usr/sbin/alternatives --install /usr/bin/java java /usr/local/jdk1.5.0_19/bin/java 100 
   $ sudo /usr/sbin/alternatives --install /usr/bin/jar jar /usr/local/jdk1.5.0_19/bin/jar 100  
   $ sudo /usr/sbin/alternatives --install /usr/bin/javac javac /usr/local/jdk1.5.0_19/bin/javac 100
   $ sudo /usr/sbin/alternatives --config java

2 Play with curl

$ cd ~/bin (make sure ~/bin is in $PATH)
$ curl http:/android.git.kernel.org/repo > ~/bin/repo
$ chmod a+x ~/bin/repo
$ cd ~/myspace/mydroid
$ repo init -u git://android.git.kernel.org/platform/manifest.git -b cupcake
$ repo sync

This example access an array which is a block of buffer.

/* bar initialize input (or 3 to each element)
 */
int bar(int* in, int n)
{
    int ret;
    __asm__(
    ".set push     \n"       // save assembler option
    ".set noreorder\n"       // suppress reordering
    "lw $9, %2     \n"       // $9 = n (counter end)
    "li $8, 0      \n"       // $8 = 0
    "li $12, 0     \n"       // $12 = 0
    "move $4, %1\n"          // $4 = in
    "loop:  \n"             
    "lw $11, ($4) \n"        // $11 = *in   
    "ori $11, $11, 3  \n"    // $11 = $11 || 3 
    "sw $11, ($4) \n"        // *in = $11
    "addi $4, $4, 4 \n"      // in++  (move to next addess)
    "addi $8, $8, 1 \n"      // move to next sample
    "bne $8, $9, loop \n"    // loop
    "sw $11, %0    \n"        // save $12 to ret
    ".set pop     \n"        // restore assembler option
    : "=m" (ret)             // to return
    : "r" (in),"m" (n)       // the input
    );
    return ret;
}

Here the use of $8 is not the best, because the move the array element is by $4, soe the $8 is not most necessary, because $4 can be used to check the range for the loop.

In the following sample, it shows how to send the input (val) and the output (ret) to assembly block.

/* foo returns (val | 3)
 */
int foo(int val)
{
    int ret;
    __asm__(
    ".set push\n"              // save assembler option
    ".set noreorder\n"         // suppress reordering
    "ori  $2, %1, %2\n"
    "sw $2, %0\n"              // save $2 to ret
    ".set pop\n"               // pop assembler option
    : "=m" (ret)               // ret: memory
    : "r" (val), "n" (3)       // val: read-only register, n: number
    );
    return ret;
}

The real code by dump is:

08804554 :
 8804554: 27bdffd0  addiu sp,sp,-48
 8804558: afbe0020  sw s8,32(sp)
 880455c: 03a0f021  move s8,sp
 8804560: afc40010  sw a0,16(s8)
 8804564: 8fc20010  lw v0,16(s8)
 8804568: 34420003  ori v0,v0,0x3
 880456c: afc20000  sw v0,0(s8)
 8804570: 8fc20000  lw v0,0(s8)
 8804574: 03c0e821  move sp,s8
 8804578: 8fbe0020  lw s8,32(sp)
 880457c: 27bd0030  addiu sp,sp,48
 8804580: 03e00008  jr ra
 8804584: 00000000  nop

0 installation and setup
1 create a project

$ android create project --target 1 --path ./demo --activity demo --package com.example.demo

2 edit source code ~/myspace/demo/src/example/demo/demo.java
3 compile with ant

$ ant -debug -verbose

4 run emulator with a script

#! /bin/sh
out/host/linux-x86/bin/emulator -verbose \
 -kernel prebuild/android-arm/kernel/kernel-qemu \
 -ramdisk out/target/product/generic/ramdisk.img \
 -system out/target/product/generic/system.img \
 -init-data out/target/product/generic/userdata.img \
 -avd myavd -sdcard ./sdcard.img -no-skin -no-boot-anim

5 install the application we have build

$ cd ~/myspace/demo
$ adb install bin/demo-debug.apk
$ adb install -r bin/demo-debug.apk (for reinstall)
$ adb shell
# logcat
# ps a (to get process id to kill)
# kill -9

That's on java side, on the android side,
1 setup

$ cd ~/myspace/mydroid
$ source ./build/envsetup.sh
$ lunch 1

2 build the project in android

$ cd ./frames/base/media/libmediaplayerservice
$ mm (it builds libmediaplayerservice library as an example)
$ cd ~/myspace/mydroid (go back to the root)
$ make snod (build the system image

then you can go back to run emulator with parameters specified in the script.

Here is the script to calculate cpu usage in MCycles per second.
The cpu speed is 222MHz as an example, processing data rate is 44100, each block has 8192 samples, and the total calls to foo is 532.

#!/bin/bash

rate=44100
blksize=8192
cpu=222
call=532

# the following val is got from gprof as percentage cpu time, 30.11%.
pcpu_foo=30.11

duration=`echo "scale=4; $blksize * $call / $rate" | bc`
echo "duration: " $duration

secs_foo=`echo "scale=4; $duration * $pcpu_foo /100" | bc` 
echo "secs_foo " $secs_foo

blksecs_foo=`echo "scale=4; $secs_foo/$call"|bc`
echo "blocksecs_foo" $blksecs_foo

cpu_foo=`echo "scale=4; $cpu * $rate / $blksize * $blksecs_foo"|bc`
echo "cpu_foo " $cpu_foo " MCycle/sec"

1. setup nfs server

$ sudo apt-get install nfs-common nfs-kernel-server
$ sudo vim /etc/exports
/opt/share *(rw,sync)
$ sudo /etc/init.d/nfs-kernel-server start

2. config static ip

$ sudo vim /etc/network/interfaces, add the following lines:
auto eth0
iface eth0 inet static
    address 192.168.0.9
    netmask 255.255.255.0
    network 192.168.0.0
    broadcast 192.168.0.255
    gateway 192.168.0.1
$ sudo /etc/init.d/networking restart

At last, I left Fedora Core 5 which I have used for these 2 years and move to Ubuntu. I am now running Ubuntu 8.04 which is not a very latest version, but at least it is newer than FC5.

But by default to build procmeter3, it prompts "X11/Intristic.h is missing". I have to install the following packages:

$ sudo apt-get install libxt-dev libxaw-headers libxaw7-dev
$ make
$ sudo make install