Learn Embedded Linux with ARMulator

uClinux is an excellent way to study the embedded operating systems for an engineer, student, hobbyist, Linux-enthusiast. I am interested in Embedded Linux for ARM microcontroller. Before buying a new mcu evaluation board, there is a smart way to study the Embedded Linux. That is studying it with the emulator called ARMUlator.

I tested on Fedora Core 6 Linux with GCC 3.4.x (how to install gcc 3.4 for FC6).

What you get

Here are some files you can use to put together uClinux running in the GDB/ARMulator.

• gdb-5.0.tar.bz2 - The orginal gdb-5.0 archive.


• gdb-5.0-uclinux-armulator-20060104.patch.gz - Patches against gdb-5.0 based heavily on the ARMulator changes from Ben Williamson with changes to behave like an Atmel AT91 device.


• linux.2.4.x.gz - A precompiled uClinux kernel binaries that you can run in the emulator.


• romfs.2.4.x.gz - romfs images to use with the above kernels.

Building the Debugger/Emulator

 tar xvf gdb-5.0.tar.bz2
 gunzip gdb-5.0-uclinux-armulator-20060104.patch.gz
        patch -p0 < gdb-5.0-uclinux-armulator-20060104.patch
 cd gdb-5.0
        export CC=gcc34
 ./configure --target=arm-elf
 make
 make install

Running the precompiled binaries

The ARMulator expects the romfs to be in a file called "boot.rom". You must use the matching kernel/romfs combo's.

 gunzip romfs.2.4.x
 gunzip linux.2.4.x
 ln -s romfs.2.4.x boot.rom
 arm-elf-gdb linux-2.4.x
 ...
 gdb> target sim
 ...
 gdb> load
 ...
 gdb> run

Finally, you should get something like this: