My first embedded linux with Buildroot and Qemu

Hi all,

I start to discover the embedded linux world. I have read the french book (because I am french ^^) "Linux embarqué" (translation => "embedded linux") written by Pierre Ficheux.

By reading this book I understood architecture and main mechanisms of an linux OS. Now I want to try !

I plan to buy a development board, but first I try to deploy a custom embedded linux OS on an emulated board, using Qemu.

I bought the "Linux Magazine" where Pierre Ficheux wrote an article "how to build an embedded linux with buildroot". I guess I am not the only one to use Buildroot, so I ask for your help because I have some trouble with that. I want to emulate a versatile ARM9 board. Here is the buildroot configuration (buildroot 2009.11) :
- Target Architecture => ARM
- Target architecture variant => ARM926T
- Target ABI => OABI
- Target Option => default configuration
- Build option => default configuration
- Toolchain => default configuration (linux kernel 2.6.31.x)
- Package selection => default configuration
- Target file system => cpio (gzip compression)
- Kernel => Same version as linux header
- config file => .config
- kernel binary format => zImage

Then, when I compile Buildroot, it ask me lot of questions (I think it is about the kernel compilation). I don't know what I have to answer to each questions, so I let the default answer.

Then I have my root file system and my kernel image.

When I want to try it I run the command :
qemu-system-arm -M versatilepb -m 16 -kernel //mykernel_path -initrd /myrootfs_path

Qemu is launching and nothing else happen. I don't have any error, but I don't have prompt... It seems that nothing is booting, or I don't know what.

My goal is to develop application on my embedded linux OS. But I can't even launch a simple OS !!

Can you tell me what is wrong, what is my mistake, what are your advice to achieve to develop an application.

I really thank you,

emping

There are pre-made images of boards available.

http://people.debian.org/~aurel32/qemu/

Thank you Mr Bisquit.

But my goal is not to use, pre-made image. I want to understand how it works, what is customizable etc.

Can I use a pre-made image of the kernel with whatever rootfs image ?

Actually, I would better have a kind of tuto "how to configure a kernel for ARM ?". You see what I mean ?

Thank you for answer.

Anyone could help me please ? I try all the day long to run something on Qemu, but nothing happen ! Please...

Thank you.

This may be because of the missing "console" kernel parameter. Try something like below

./qemu-system-arm -M versatilepb -kernel zImage -serial mon:stdio -initrd newbbfsramfs.cpio.gz -append "console=ttyAMA0"

Since I used monitor and console the same in QEMU, you may need to use
"Ctrl-a" and then "c" to switch between monitor and console.

Best regards,
Suresh Maniyath

Thank you Suresh Maniyath. Rather than to use Qemu to learn embedded linux, I bought a Mini2440 development board. Now I have troubles in developing my own application especially in playing sound. Please see my post "SDL cross compiled troubles" if you are interested in.

Have a good day.