linux 上的dnw程式

由於工作機是linux,每次要燒image都要切到windows不方便，

在網路上有找到別人寫的dnw程式，不過沒有作checksum的部份，就把他補上去了

ps.

1.系統需要先安裝libusb

2.使用時vid/pid可能需要依據裝置修改

/*

* cy add checksum

* use: gcc dnw2.c -o dnw2 -lusb -g

*/

/* dnw2 linux main file. This depends on libusb.

*

* Author: Fox

* License: GPL

*

*/

#include

#include

#include

#include

#include

#include

#define QQ2440_SECBULK_IDVENDOR 0x04e8

#define QQ2440_SECBULK_IDPRODUCT 0x1234

struct usb_dev_handle * open_port()

{

struct usb_bus *busses, *bus;

usb_init();

usb_find_busses();

usb_find_devices();

busses = usb_get_busses();

for(bus=busses;bus;bus=bus->next)

{

struct usb_device *dev;

for(dev=bus->devices;dev;dev=dev->next)

{

if( QQ2440_SECBULK_IDVENDOR==dev->descriptor.idVendor

&& QQ2440_SECBULK_IDPRODUCT==dev->descriptor.idProduct)

{

printf("Target usb device found!\n");

struct usb_dev_handle *hdev = usb_open(dev);

if(!hdev)

{

perror("Cannot open device");

}

else

{

int ret;

if(ret = usb_claim_interface(hdev, 0) != 0)

{

perror("Cannot claim interface");

printf("ret=%d\n", ret);

usb_close(hdev);

hdev = NULL;

}

}

return hdev;

}

}

}

printf("Target usb device not found!\n");

return NULL;

}

void usage()

{

printf("Usage: dnw2 \n\n");

}

unsigned char* prepare_write_buf(char *filename, unsigned int *len)

{

unsigned char *write_buf = NULL;

struct stat fs;

int fd = open(filename, O_RDONLY);

if(-1==fd)

{

perror("Cannot open file");

return NULL;

}

if(-1==fstat(fd, &fs))

{

perror("Cannot get file size");

goto error;

}

write_buf = (unsigned char*)malloc(fs.st_size+10);

if(NULL==write_buf)

{

perror("malloc failed");

goto error;

}

if(fs.st_size != read(fd, write_buf+8, fs.st_size))

{

perror("Reading file failed");

goto error;

}

printf("Filename : %s\n", filename);

printf("Filesize : %x bytes\n", (int)fs.st_size);

*((u_int32_t*)write_buf) = 0xC0000000; //download address

*((u_int32_t*)write_buf+1) = fs.st_size + 10; //download size;

//cy: compute checksum

int k;

u_int16_t csum=0;

for(k=0; k<(int)fs.st_size; k++){

csum +=write_buf[8+k];

}

printf("CheckSum=%d\n",(int)csum);

write_buf[fs.st_size+ 8] = csum; //checksum;

write_buf[fs.st_size+ 9] = csum>>8; //checksum;

//printf("write_buf[%d]=%.2x\n", (int)fs.st_size + 8, write_buf[(int)fs.st_size + 8]);

//printf("write_buf[%d]=%.2x\n", (int)fs.st_size + 9, write_buf[(int)fs.st_size + 9]);

*len = fs.st_size + 10;

return write_buf;

error:

if(fd!=-1) close(fd);

if(NULL!=write_buf) free(write_buf);

fs.st_size = 0;

return NULL;

}

int main(int argc, char *argv[])

{

if(2!=argc)

{

usage();

return 1;

}

struct usb_dev_handle *hdev = open_port();

if(!hdev)

{

return 1;

}

unsigned int len = 0;

unsigned char* write_buf = prepare_write_buf(argv[1], &len);

if(NULL==write_buf) return 1;

unsigned int remain = len;

unsigned int towrite;

printf("Writing data ...\n");

while(remain)

{

towrite = remain>512 ? 512 : remain;

if(towrite != usb_bulk_write(hdev, 0x2, write_buf+(len-remain), towrite, 3000))

{

perror("usb_bulk_write failed");

break;

}

remain-=towrite;

printf("\r%d%%\t %d bytes ", (len-remain)*100/len, len-remain);

fflush(stdout);

}

if(0==remain) printf("Done!\n");

return 0;

}

wpa_supplicant 連線 wpa-psk-ccmp 的ap

ps. 有些ap上面是寫AES而不是CCMP

ctrl_interface=/var/run/wpa_supplicant

network={

ssid="xxxxxx"

key_mgmt=WPA-PSK

proto=WPA

pairwise=CCMP

group=CCMP

psk="xxxxxxxxxx"

}

N1 泡水機拆解

螢幕進水

鏡頭進水＆金屬生鏽

生鏽...

燒焦？

主電路板

螢幕背面與電容試觸控

軌跡球

超薄的oled

android 螢幕旋轉演算法

eclair只支援兩種方向：rotation 0 and rotation 90

CyanogenMod有支援四個方向

最新的froyo應該是支援三個方向（等froyo release再把他的演算法po上來）

source code 在 framework/base/core/java/android/view/WindowOrientationListenetr.java這裡支援的方向指的是android送給上層依據目前g-sensor算出來的螢幕旋轉方向，

程式部份自己要去對旋轉的方向作處理，預設的setting程式就有支援四個方向，

ui(Launcher)部份，把AndroidManifest.xml的android:screenOrientation="nosensor"改成sensor就可以了

以下是詳細的演算法：

CyanogenMod 有支援四個方向，基本上是從原本eclair的演算法算出orientation之後的部份作修改：

android 繪圖程式範例

拿這個範例改的（修正原本要畫完放開滑鼠之後才會出現線段）

http://www.tutorialforandroid.com/2009/06/drawing-with-canvas-in-android.html

source code:

package com.cyl.android.draw;



import java.util.ArrayList;

import android.app.Activity;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Path;

import android.os.Bundle;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;



public class draw extends Activity {

private ArrayList _graphics = new ArrayList();

private Paint mPaint;







@Override

 public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

     setContentView(new DrawingPanel(this));

     mPaint = new Paint();

     mPaint.setDither(true);

     mPaint.setColor(0xFFFF0000);

     mPaint.setStyle(Paint.Style.STROKE);

     mPaint.setStrokeJoin(Paint.Join.ROUND);

     mPaint.setStrokeCap(Paint.Cap.ROUND);

     mPaint.setStrokeWidth(3);



}







class DrawingPanel extends SurfaceView implements SurfaceHolder.Callback {

private DrawingThread _thread;

private Path path;



public DrawingPanel(Context context) {

 super(context);

         getHolder().addCallback(this);

         _thread = new DrawingThread(getHolder(), this);

}



@Override

     public boolean onTouchEvent (MotionEvent event) {

         synchronized (_thread.getSurfaceHolder()) {

          if(event.getAction() == MotionEvent.ACTION_DOWN){

           path = new Path();

           path.moveTo(event.getX(), event.getY());

          }else if(event.getAction() == MotionEvent.ACTION_MOVE){

           path.lineTo(event.getX(), event.getY());

           _graphics.add(path);

           path = new Path();

           path.moveTo(event.getX(), event.getY());

          }else if(event.getAction() == MotionEvent.ACTION_UP){

           path.lineTo(event.getX(), event.getY());

           _graphics.add(path);

          }

        

          return true;

         }

}



@Override

     public void onDraw(Canvas canvas) {

 for (Path path : _graphics) {

  canvas.drawPath(path, mPaint);

 }

}







public void surfaceCreated(SurfaceHolder holder) {

 // TODO Auto-generated method stub

 _thread.setRunning(true);

         _thread.start();

}



public void surfaceDestroyed(SurfaceHolder holder) {

 // TODO Auto-generated method stub

 boolean retry = true;

         _thread.setRunning(false);

         while (retry) {

             try {

                 _thread.join();

                 retry = false;

             } catch (InterruptedException e) {

                 // we will try it again and again...

             }

         }

}



@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

  int height) {

 // TODO Auto-generated method stub



}

}



class DrawingThread extends Thread {

     private SurfaceHolder _surfaceHolder;

     private DrawingPanel _panel;

     private boolean _run = false;



     public DrawingThread(SurfaceHolder surfaceHolder, DrawingPanel panel) {

         _surfaceHolder = surfaceHolder;

         _panel = panel;

     }



     public void setRunning(boolean run) {

         _run = run;

     }



     public SurfaceHolder getSurfaceHolder() {

         return _surfaceHolder;

     }



     @Override

     public void run() {

         Canvas c;

         while (_run) {

             c = null;

             try {

                 c = _surfaceHolder.lockCanvas(null);

                 synchronized (_surfaceHolder) {

                     _panel.onDraw(c);

                 }

             } finally {

                 // do this in a finally so that if an exception is thrown

                 // during the above, we don't leave the Surface in an

                 // inconsistent state

                 if (c != null) {

                     _surfaceHolder.unlockCanvasAndPost(c);

                 }

             }

         }

     }

 }

}

取得LINUX系統記憶體剩餘空間

在linux下，沒用到的記憶體空間會被拿來當作buffer/cache使用，

以加速I/O存取

所以會感覺記憶體占用很多，

其實實際上如果程式需要記憶體，

就會釋放buffer/cache的空間，所以通常記憶體幾乎都是保持在很高的使用量。



使用free指令，

"-/+ buffers/cache"那一行的free就是實際上系統剩下來沒被其他程式吃掉的記憶體大小


可以用以下的指令取得真實的剩餘空間
echo -n free memory:;free -m | grep buffers/cache | awk '{print $4}'

C陣列與指標

宣告陣列時，
無論是幾維的陣列，
C語言都以分配一塊連續的記憶體空間來處理。


所以這種時候，可以把它當一維陣列處理

C以row為主，假設是二維陣列 arr[2][2]
當一維時的順序就是:
arr[0][0] arr[0][1] arr[1][0] arr[1][1]




雖然指標和陣列用起來差不多，
不過實際上意義是不太一樣的，
可以參考
http://dascan.pixnet.net/blog/post/15600458
http://squall.cs.ntou.edu.tw/cprog/Materials/AdvancedArray.html





要宣告一個指標代表陣列，要用以下的方法:

int data[5][5][5][5];
int (*p)[5][5][5];

可以參考
http://blog.udn.com/cchahacaptain/2197712