android notes - build and test shared library

1. download system.tar.gz from benno and extract it to ~/myspace/tmp.
2. make a link.

cd ~/myspace/tmp/system/lib
ln -s libc.so libc.so.6

Is it necessary? but it fixed the problem to looking for libc.so.6.
3. Here is the Makefile.

CC=arm-none-linux-gnueabi-gcc
LD=arm-none-linux-gnueabi-ld
AR=arm-none-linux-gnueabi-ar
LD_OPTS= --entry=_start \
    --dynamic-linker /system/bin/linker -nostdlib \
    -rpath /system/lib -rpath ~/myspace/tmp/system/lib  \
    -L ~/myspace/tmp/system/lib -L .
foo2.a : foo2.c 
 $(CC) -g -fpic -c foo2.c 
 $(CC) -g -shared -nostdlib -o libfoo2.so  foo2.o
 $(AR) -rcs $@ foo2.o
foo2: main.c start.c foo2.a
 $(CC) -g -c main.c
 $(CC) -g -c start.c
 $(LD) $(LD_OPTS) -lc  -lfoo2  -o foo2  main.o  start.o

when build the library, should set "-nostdlib"

4. run the commands

$ make foo2
$ adb push libfoo2.so /data
$ adb push foo2 /data
$ adb shell
# cd data
# ./trace ./foo2