uClinuxforS3CEV40 English V3.1

8/13/2019 uClinuxforS3CEV40 English V3.1

1/19

- 1 -

About uClinuxs Fast Installation Configuration

Compilation and Run

1 Installation and Configuration of Cygwin

The latest Cygwin can be downloaded from its website http://www.cygwin.com. As

well as you can find it at the enclosed CD of this book, which version is 1.5.10-3, locates

at CD2_S3CEV40 Tools\Cygwin 1.5.10. The release date of version 1.5.10 is May,

2004. You also need to unzip it before installation.

1) Run setup.exe, choose the Install from Local Directory then click Next Step .

Please refer to the below fig. 0-1.

Fig. 0-1 Installation of Cygwin

2) Choose installation directory. Please note the installation directory must locates at

the NTFS partition of the hard disk, or it will affect the file attributes thus leads to

an error.

If your hard disk is not in the NTFS format, you need to convert it into NTFS under

DOS. For example you can use this DOS command: convert F: /FS:NTFS. Please

note this command can only be used under Win2000 or above. After you execute

the convert command, restart the PC. So the partition can be changed into NTFS.

Select the Unix Text File Type, then click Next Step. More details please refer to

the below fig. 0-2.


2/19

- 2 -

Fig. 0-2 Choose Installation Directory

3) Select local package directory for example \cygwin 1.5.1\cygwin. Then click

Next Step. As fig. 0-3 shows.

Fig. 0-3 Select Local Package Directory


3/19

- 3 -

4) Select Packages. You can adjust the packages by clicking Default which is at the

left hand side of the dialog window. In order to be able to develop ucLinux, the

below packages must be selected.

Admin Includes boot service tools such as cygrunsrv and so

on. Necessary for booting NFS.

Archive Compress or decompress files tools

Base Basic Linux tools

Devel Development kit, includes gcc, make etc.

Libs Function Library

Net Network tools

Shells General Shell tools

Utils Tools such as bzip2 etc.

Fig. 0-4 Select packages

Do step by step according to the prompt after the packages are installed, then you can

normally run the Cygwin.

2 Install the source code of uClinux

Source code of uClinux can be found at the uClinux Source directory of the

accompanying CD of this book. That is CD1_S3CEV40 General\Software\uClinux for


4/19

- 4 -

S3CEV40\uClinux-s3cev40.tar.gz.Please copy it to directory cygwin/usr/local/src. If the

folder src is not existing. Please execute the command mkdir /usr/local/src to create it.

In order to unzip it, please execute the following commands:

cd /usr/local/src

tar xzvf uClinux-s3cev40.tar.gz

After the commands are fully executed, if there is a prompt as:tar: Error exit delayed from previous errors

Please ignore this prompt due to it is normal.

Once the decompression is finished, there will be directory named uclinux-s3cev40

under /usr/local/src, which is used to put the source code. Hereafter all the operation will

be acted under this directory.

Please note, the latest ucLinux source code can be downloaded here:

http://www.uclinux.org/pub/uClinux/dist

3 Installation of development toolchain

l Installation of ARM toolchain

The toolchain installation software can be found at the directory of the accompanying

CD1 of this book. It is CD1_S3CEV40 General\Software\uClinux for S3CEV40\Cross

compiler for Cygwin:

Fig. 0-5 Installation of Cygwin ARM Toolchain for ucLinux

Fix the installation directory at the above dialog. The Arm toolchain will be installed to

the directory of /usr/local/armtools.

l Path configuration of the ARM toolchain

After the installation was finished, please run the below command at the Cygwin

console, so that the installation path of ARM toolchain can be regarded as a system default

path. Please make sure that the path of ARM toolchain has been regarded as the system

default path before compiling ucLinux.

export PATH=/usr/local/armtools/bin:$PATH


5/19

- 5 -

Another way is to modify the /home/.bash_profile, add the above command to the

end of the file. After this, this command will be auto-executed when the console boots.

4 Config the uClinux

Run the command below to config the ucLinux.

cd /usr/local/src/ uclinux-s3cev40

make xconfig

The configuration dialog window is as the fig. 0-6.

Fig. 0-6 Embedded Linux Configuration

Click Vendor/Product Selection, a new dialog window is as fig. 0-7 below:

Fig. 0-7 Vendor/Product Selection

Choose Embest at Select the Vendor you wish to target, then click Main Menu

return to the main configuration interface.

Click Kernel/Library/Defaults Selection at the main configuration interface, you will

see a new dialog window as fig. 0-8:


6/19

- 6 -

Fig. 0-8 Kernel/Library/Defaults Selection

Option Meanings Configuration(default)

Vendor/Product select the Vendor/Product Embest/S3C44B0

Kernel Select the Kernel Linux-2.4.x

Libc VersionSelect the version of

library versionuClibc

Default all Settings Default all Settings

Customize Kernel Settings Customize Kernel SettingsCustomized by

customer

Customize Vendor/User SettingsCustomize Vendor/User

Settings

Customized by

customer

Update Default Vendor SettingsUpdate Default Vendor

Settings

Diagram 1-1 Target platform option

Choose linux-2.4.x at the Kernel Version option; And choose uClibc at the Libc

Version option.

Please choose n(no) at Customize Kernel Settings and Customize / Vendor/User

Settings options because uClinux-s3cev40 has been set properly after released. Or you

can choose to customize it by yourself.

Then click Main Menu return to the main configuration interface.Click Save and Exit at the main configuration interface, by now the ucLinux

configuration is finished.

5 Compile uClinux

In order to compile ucLinux, please execute the following commands under Cygwin

orderly:

make dep

make clean

make lib_only


7/19

- 7 -

make user_only

make romfs

make image

The above commands comments are as below:

Make dep Search the relationship between the compile output of ucLinux andsource code, hereby generate the rely files.

Make clean Delete all the object files, module files and temporary files which are

generated while creating the kernel.

Make lib_only To compile the uC-libc function library, then generate function library

files such as libc.a libm.a and so on.

Make user_only To compile the applications.

Make romfs To generate the Romfs file system, using applications which are well

compiled (romfs directory).

Make image Use the romfs directory to generate file system image, then compile the

kernel, thus get the kernel image.

Finally we get these two files under images directory:

zImage Executive image file of uClinux, kernel 2.4.x.

romfs.img Image of file system

zImage has included the image of file system, so you can use it to burn the Flash chip

directly.

6 Burn ucLinux kernel

1 Config the Embest Online Flash Programmer at first

Connect the JTAG interface of Embest emulator with JTAG interface of Embest

S3CEV40, meantime connect the parallel port of Embest emulator with parallel port of PC

host.

Run the Embest Online Flash Programmer for ARM, click FileOpen, load the

CD1_S3CEV40 General\Software\S3CEV40\EmbestS3CEV40.cfg

Click SettingConfigure, the configuration dialog window is as fig. 0-9:


8/19

- 8 -

Fig. 0-9 Flash Programmer configuration

Select Flash chip SST39LF/VF160 as above fig. 0-9.

Select S3C44B0X as fig. 0-10:

Fig. 0-10 Select CPU


9/19

- 9 -

2 Program the image file

First we need to download bootloader, which locates at CD1_S3CEV40

General\Software\Image\uclinux\blob.s3cev40.bin. Select sector 1-16 of the flash as fig.

0-11.

Fig. 0-11 Download the bootloader

Download zImage to the 17-192 section Flash address, which locates at

CD1_S3CEV40 General\Software\Image\uclinux\zImage, please refer to fig. 0-12

Fig. 0-12 Download the zImage


10/19

- 10 -

Then download the romfs.img at 193-400 sector of the flash following above the method.

please refer to following fig

7 Run uClinux

Use the accompanying serial cable to connect UART0 of target board with COM1 of PChost.

Run the HyperTerminal at PC host, set to 115200 baud rate, 8, N/A, 1, N/A. Please

refer to fig. 0-13:


11/19

- 11 -

Fig. 0-13 Configuration of HyperTerminal

Run the ucLinux, result is as fig. 0-14 shows:

Fig. 0-14 Interface when running uClinux


12/19

- 12 -

8 To develop a simple application under uCLinux

Here we will introduce the basic steps regarding how to develop applications under

uCLinux. In this example, we will create a simple application and add it to file system.

Hardware requirement: EmbestS3CEV40 platform, PC host, Embest

Emulator/PowerICE/UNetICE JTAG debugger,

Software requirement: Cygwin under Windows 98/2000/NT/XP, Embest Online Flash

Programmer

1 Steps:

1. Preparation. Use the accompanying serial cable to connect UART0 of target board

with serial port of PC host. Meantime connect Embest Emulator/PowerICE/UNetICE JTAG

debugger with Embest S3CEV40 board.

2. Run the HyperTerminal at PC host, set to 115200 baud rate, 8, N/A, 1, N/A.

3. Create a new directory app under /usr/local/src/uClinux-s3cev40/user/ so that

you can put led.c and makefile (under example) into it. Please execute the command

below:

$:mkdir p /usr/local/src/uClinux-s3cev40/user/app

Copy led.c and Makefile, which locates at CD1_S3CEV40 General\Software\uClinux

for S3CEV40\example to the app directory.

Makefile is used to manage the application project. By using it, you are able to configthe object file, compiler, parameter, routine, deletion regulation etc.

4. Edit the configuration file

Add the application information into the configuration option by editing the

configuration file, so that the new application can be regarded as the file systems own

users application. Edit the /usr/local/src/uClinux-s3cev40/config/config.in as the

diagram below:

########################################################################

mainmenu_option next_comment

comment 'User Application'

bool 'Led' CONFIG_USER_LED

comment "User Application"

endmenu

########################################################################

After this is done, you will see a menu User Application at the user application

configuration interface.

5. Edit the Makefile

Edit the \cygwin\usr\local\src\uClinux-s3cev40\user\Makefile to add our new

application. Please add the sentence below to

\cygwin\usr\local\src\uClinux-s3cev40\user\Makefile.


13/19

- 13 -

dir_$(CONFIG_USER_LED) += app

Usually compiler will visit the new applications automatically to get the necessary

information.

6. To compile the ucLinux

Re-compile the ucLinux, so that the new application will be added to file system.

Then burn the file system to the corresponding section of Flash, then run it.

export PATH=/usr/local/armtools/bin:$PATH

make xconfig

make dep

make lib_only

make user_only

make romfs

make image

Please note: When using the make xconfig, select Kernel/Library/Defaults

Selection, then click Y at Customize Ventor/User Setting and return and click save

and exit. Then choose User Application at the pop-up Application Configuration window.

Then choose led at the User Application. More details please refer to the fig. below.

(a)

(b)

If you amended the application and want to re-compile it, you can just start at the

command make user_only.

7. Load EmbestS3CEV40.cfg at the Embest Flash Programmer, then download

bootloader blob.s3cev40.bin to Flash address 1-16 sector. Download zImage to Flash

address 17-192 sector and romfs.img to the 193-400 sector.


14/19

- 14 -

8. Run ucLinux at the Embest S3CEV40 platform. You can observe the running of

ucLinux by using HyperTerminal. Once ucLinux is fully booted, you can see the interface as

below:

Sash command shell (version 1.1.1)

/>

Enter directory bin then run led application:/>cd bin

/bin>led

Thus you can see LED1 and LED2 turn on and off and the same time .

2 Example code as reference

/*******************************************************

* File Name led.c

* Description timing interrupt

* Author * Date

*******************************************************/

#include

#include

#include

/*define port configuration register and port data register address*/

#define PCONB (*(volatile unsigned *)0x01D20008)

#define PDATB (*(volatile unsigned *)0x01D2000C)

int i=0;

/*you may modify the value of PDATB and change the led output.PB9

and PB10 are corresponding pins to led1 OUTPUT and led2 OUTPUT.

Howover,each of port B pins is controled by register PDATB.SO you

may modify the corresponding bit of PDATB to control the led OUTPUT.*/

static void sig_alarm(int signumber)

{

if(i==0)

{

PDATB |= 0xFF;

i = 1;

}

else

{

PDATB &= 0xCF;

i = 0;

}

alarm(2);

}

int main(void){

if(signal(SIGALRM,sig_alarm) == SIG_ERR)


15/19

- 15 -

{

printf("some error occurs\n");

return 1;

}

alarm(2);

while(1);

return 0;}

9 Add application program fast

The procedures of adding application programs and its compilation and execution

are formal, but very complex, it is inconvenient for user while in development and

debug, user can add application programs fast while in development and debug follo

wing the instructions below:

1) Compile and generate executable file

Enter the following commands to directly compile the source code file of the pro

gram, for more complex projects, we can use Makefile as described in above part:

arm-elf-gcc Wall O2 -Wl,-elf2flt o led led.c

The led generated is in flat format, which can directly run under uClinux.

2) Copy executable file to file system.

romfs directory is a generated file system directory, it is generated when execut

ing make romfs command, if user has executed make romfs command, he can co

py the generated executable file led to the directory romfs/bin, no need execute t

he command again. Caution: if user has executed make clean command, all the c

ontents under romfs will be cleaned.

3) Generate images of file system

User can directly execute the following command to generate images of file syst

em romfs.img in the uclinux-s3cev40 folder:

genromfs -v -V "ROMdisk" f romfs.img -d /usr/local/src/uclinux-s3cev40/romfs

Now the images of file system romfs.img includes the new application program l

-ed.

10. Methods of debug application program

In general, there are following three methods to debug the application programs

in uClinux:

1) Host debug

In Linux operating system or PC hosts using Cygwin Windows operating system,

user can use host (x86)-based development and debug tool, e.g. GCC and GDB to compile and debug application program, when the debug is successful, use cross


16/19

- 16 -

compiler arm-elf-gcc to conduct secondary compilation, in the end, transplant it t

o uClinux system for running.

This method has wide variety of tools for your choice, and it is fast, especially s

uitable for prophase debug of large complex applications.

In this method, user must pay attention to the concerns of implanting from Linu

x to uClinux, the biggest concerns are the difference between uClinux functions andLinux functions, and using Vfork to substitute fork.

2) Serial port printing debug

Serial port printing debug information is an important debug approach for uClinu

x to develop application program.

The moment the program directly runs in target board, the target board is conn

ected with host through serial port, the information output during the running of pro

gram is displayed in the serial port terminal of the host.

The programmer adds Printf sentences to source code of program at appropriate

location, after compilation, when the program runs to specific sentence while runni

ng on Uclinux, it will print some important variables, parameters onto terminal interf

ace through serial port at real-time, allow the developer to observe the running stat

us of the program in timely way, and provide important basis and information for fu

ture amendment and optimization.

3) Remote interactive debug

Run gdbserver on uClinux system, The communication between the target syste

ms such as GDB of ARM running in host and gdbserver of the target board are reali

zed through serial port or Ethernet, gbserver controls the running of program and fe

edback the running status of program with debug instructions of GDB.

In the above debug methods, codes are frequently modified and recompiled, so

how to download the application to uClinux fast and conveniently is another concern

of developer during the debug, we will introduce a the most common approach to

download and debug application programs in the following section:

FTP/TFTP method

11. TFTP transfer debug program

1) Trivial file transfer protocol

The Trivial File Transfer Protocol (TFTP) is suitable for the transfer of small files,

it is small and easy to realize. TFTP also uses customer server, but it uses UDP da

ta report (UDP 69 port), so TFTP must have its own error-correcting action. TFTP on

ly supports file transfer, doesnt support interaction, and it has no a big command s

et. Its advantages: I. It can be used in UDP environment. TFTP is suitable for the c

ase when program or file need be downloaded to a number of computers concurrent

ly. II. TFTP codes occupies smaller memory, some equipment doesnt need hard dis


17/19

- 17 -

k, small-capacity solidified fixed TFTP, UDP and IP memory is enough; its disadvant

ages: transfer is less reliable, no password, etc.

TFTP is usually applied in the development of uClinux.

2) Establish FTP/TFTP server in PC

Run tftpd32.exe, the TFTP server program, to setup working status, authority an

d local tftp directory, in default state, it will directly start working, and current direc

tory is the default local tftp directory.

Figure 11-1 Interface of TFTP server

3) Transfer application program by means of TFTP (take multithreaded

program for example)

Prepare experimental environment, use the serial port cable supplied with Embest

S3CEV40 target board to connect UART0 and PCs serial port COM1 of target board,

use the net cable supplied with Embest S3CEV40 target board to connect the net

port of target board and PC.

Run Windowss own super terminal serial port communication program in PC, set

Baud Rate of 115200, 1 stop bit, no panty bit, no hardware flow control.

Run tftpd32.exe in PC, setup the path to point at the binary file evfork.

Run uClinux embedded system on Embest S3CEV40 target board, you will see the

following interface in the super terminal screen:

Sash command shell (version 1.1.1)

/>


18/19

- 18 -

Run cygwin in PC, compile the routine evfork.c in routine list, execute the following

commands, a binary file evfork will be generated:

arm-elf-gcc o evfork evfork.c elf2flt

Execute TFTP command in super terminal window to download the program evfork

to file system of target board, when the command is accomplished, a executable

file evfork will appear in the var folder under root directory uClinux.

Notice: 192.192.192.39 is IP address of PC.

/>tftp g l /var/evfork r evfork 192.192.192.39

Execute the following command in super terminal window, first add executable

authority for evfork file, then run the program.

/>cd var

var>chmod 777 evfork

/var> ./evfork

i am the child process, my process id is 21end pid is 21

i am the parent process, my process id is 20

Figure 11-2

source code for reference:

#include

#include

#include

main() {

int pid;

//creat the child process.

pid=vfork();

//execute process according to the pid returned.


19/19

- 19 -

if (pid < 0)

//creat failed.

printf("error in fork!\n");

else if (pid == 0)

//return 0 ,exec the child.

printf("i am the child process, my process id is %d\n",getpid());

else {

//return the child pid,exec the parent.

printf("i am the parent process, my process id is %d\n",getpid());

exit(0);

}

printf("end pid is %d\n",getpid());

}

uClinuxforS3CEV40 English V3.1

Documents

Transcript of uClinuxforS3CEV40 English V3.1