set ulimit on Mac

http://unix.stackexchange.com/questions/108174/how-to-persist-ulimit-settings-in-osx-mavericks

Install Android SDK

You are two options:

1. Install stand-alone version
1) read the Readme
        Basically, you need to run  $ tools/android update sdk --no-ui
2) platform-tools contains tools including ADB.
3) you need to add the /Users/Username/Development/android-sdk-macosx/platform-tools into the $PATH or you can run it locally.

2. Instal the version with Eclipse

http://developer.android.com/sdk/index.html

ADB errors

1. ADB error: device not found

http://stackoverflow.com/questions/21408674/adb-error-device-not-found

2. ADB error: device offline

It is because of an old version of ADB (e.g., 1.0.29). It requires 1.0.31 or greater. 

http://stackoverflow.com/questions/10680417/error-device-offline

Parameter passing inline gcc assembly error

This does not work: 

static void beep(unsigned short divisor)
{
    __asm__ volatile(
// set 8254 timer contol register to accept divisor
// IO port: 0x43
// 0xb6: 1011 0110
// channel2, access mode lo and hi, square wave
                "movb $0xb6, %%al\n"
                "out %%al, $0x43\n"

// load the divisor into ax
"mov %0, %%ax\n"

// set the low 8 bits of time2 counter
// IO port: 0x42
                "out %al, $0x42\n"

// set the high 8 bits of timer2 counter
// IO port: 0x42
                "movb %ah, %al\n"
                "out %al, $0x42\n"

// configure Speaker IO controller Port 0x61
// save the contents of 0x61
    "in $0x61, %al\n"
"movb %al, %ah\n"
// set bit 0, 1 to 1; enables the timer and NAND gate
                "or $0x3, %al\n"
                "out %al, $0x61\n"

// Run spin loop to delay
"mov $0x50E0, %cx\n"
"BEEP_DELAY: nop\n"
"nop\n"
"loop BEEP_DELAY\n"

// Trun off the speaker
"mov %ah, %al\n"
"out %al, $0x61"
:
:"r" (divisor)
   );
}

This works: 

static void beep(unsigned short divisor)
{
    __asm__ volatile(
// set 8254 timer contol register to accept divisor
// IO port: 0x43
// 0xb6: 1011 0110
// channel2, access mode lo and hi, square wave
                "movb $0xb6, %%al\n"
                "out %%al, $0x43\n"

// load the divisor into ax
"mov %0, %%ax"
:
:"r" (divisor)
   );

    __asm__ volatile(

// set the low 8 bits of time2 counter
// IO port: 0x42
                "out %al, $0x42\n"

// set the high 8 bits of timer2 counter
// IO port: 0x42
                "movb %ah, %al\n"
                "out %al, $0x42\n"

// configure Speaker IO controller Port 0x61
// save the contents of 0x61
    "in $0x61, %al\n"
"movb %al, %ah\n"
// set bit 0, 1 to 1; enables the timer and NAND gate
                "or $0x3, %al\n"
                "out %al, $0x61\n"

// Run spin loop to delay
"mov $0x50E0, %cx\n"
"BEEP_DELAY: nop\n"
"nop\n"
"loop BEEP_DELAY\n"

// Trun off the speaker
"mov %ah, %al\n"
"out %al, $0x61\n"
   );
}

PS2 Keyboard Info

http://www.computer-engineering.org/ps2keyboard/

http://wiki.osdev.org/PS/2_Keyboard

http://wiki.osdev.org/%228042%22_PS/2_Controller

How to install setuptools under a local python

Supposed you have a local python, which is used to built other staff. For example, buildozer will have this

src/.buildozer/android/platform/python-for-android/build/hostpython/Python-2.7.2

And this Python is missing setuptools for compiling, you need to install it under this Python. 

manual download the development version of setuptools from https://pypi.python.org/pypi/setuptools#downloads

move this setuptools into the Python directory

cd into the setuptools direcotry

find the executable for this python

run ../python.exe[where your python executable is] setup.py install

this will install setuptools under the local python. 

Note using easy_install setup tools only installs in your system not the local Python.