[HOWTO] Build RTEMS tool-chain for OpenRISC targets

This post provides two methods of building RTEMS tool-chain for OpenRISC 1000 architecture: 1) building from RSB (RTEMS Source Builder) and 2) building each tool/program separately by downloading official tools' releases and apply our RTEMS specific patches to them. Merely, RSB is responsible for all the stuff including: setting up the environment, downloading releases, applying patches, configuring, building, and installing all the tools. The resulted tools should be program prefixed with or1k-rtems4.11-*. You may want to have a look at OpenRISC ELF GNU tool-chain; but note that RTEMS applications can't be built via these tools. The tool-chain has been tested and used on Fedora 20 and Ububtu 12.04 LTS. 

The tools/programs releases in the time being this post was written are:

• binutils-2.24
• gcc-4.8.2
• newlib-2.1.0
• gdb-7.7
• or1ksim-github-head

Building RTEMS from RSB

Please have a look at RSB documentation here. It provides details in a thorough manner about RSB: how to download RSB, check environment, build RTEMS tool-chain for a specific target. Also, it gives a clear picture how RSB works internally.

1- Setup development and work space

$mkdir ~/rtems-dev

$cd ~/rtems-dev

2- Clone RSB 

$ git clone git://git.rtems.org/rtems-source-builder.git
$ cd rtems-source-builder

3- Check host environment

Check if host environment is setup correctly.

$ source-builder/sb-check

This command will tell you if any packages are required to be installed, if you miss any, please install them and try again, once every thing is Ok, you should have the following message:

$ source-builder/sb-check
RTEMS Source Builder environment is ok

 4- Building

$ cd rtems
$ ../source-builder/sb-set-builder --log=l-or1k.txt --prefix=$HOME/rtems-dev/rtems/4.11 \ 4.11/rtems-or1k

5- Check if all tools are installed successfully. You should get the following results

$ ls $HOME/rtems-dev/rtems/4.11
bin include lib libexec share or1k-rtems4.11
$ ls $HOME/development/rtems/4.11/bin

 

6- Add the newly installed tool-chain to the executable PATH

$ export PATH=$PATH:/$HOME/development/rtems/4.11/bin

Building RTEMS manually 

Currently, all or1k and RTEMS related patches are not upstreamed. So, we have to download official releases and apply patches to support or1k and RTEMS to them. I have worked on combining both or1k and RTEMS patches for all the tools against official tool releases. The following method of building the tools should be temporal. Eventually all patches including or1k and RTEMS should be upstreamed and tools should be built without patches provided here. 

1- Setup development and work space

$mkdir ~/rtems-dev

$cd ~/rtems-dev

2- Get the sources

• binutils-2.24
• gcc-4.8.2
• newlib-2.1.0
• gdb-7.7

3- Get the patches

Download all patches for the previous binutils, gcc, newlib, gdb releases from my repo; preferably, the latest patches (with respect to commit time). Put them in the same directory. 

4- Unpack archives 

$ tar xf binutils*.tar.* 
$ tar xf gcc*.tar.* 
$ tar xf newlib*.tar.* 
$ tar xf gdb*.tar.*

5- Apply patches

$ cd binutils-2.24
$ cat ../binutils*.diff | patch -p1
$ cd ../gcc-4.8.2
$ cat ../gcc*.diff | patch -p1
$ cd ../newlib-2.1.0$ cat ../newlib*.diff | patch -p1
$ cd ../gdb-7.7
$ cat ../gdb*.diff | patch -p1

 $ cd ../ 

6- Configure and build tools

• Create build directories for all the tools

$ mkdir b-binutils b-gcc b-gdb

• Configure and build binutils

$ cd b-binutils
$ ../binutils-2.24/configure --target=or1k-rtems4.11 --prefix=$HOME/rtems-dev/rtems/4.11
$ make
$ make install

• Setup the PATH to include binutils binaries 

$ export PATH=$PATH:/$HOME/rtems-dev/rtems/4.11/bin

• Link newlib into gcc directory

$ cd ../gcc-4.8.2/
$ ln -s ../newlib-2.1.0/newlib .

• Configure and build gcc and newlib

$ cd ..
$ cd b-gcc
$ ../gcc-4.8.2/configure --target=or1k-rtems4.11 --prefix=$HOME/rtems-dev/rtems/4.11 --with-gnu-as --with-gnu-ld --enable-languages="c,c++" --enable-threads --disable-libssp --with-newlib --with-system-zlib --disable-libstdcxx-pch --disable-nls --without-included-gettext --disable-win32-registry --disable-lto --enable-newlib-io-c99-formats

$ make 

$ make install

• Configure and build gdb

$ cd ../
$ cd b-gdb$ ../gdb-7.7/configure --target=or1k-rtems4.11 \
--prefix=$HOME/rtems-dev/rtems/4.11 \
--verbose --disable-nls \
--without-included-gettext \
--disable-win32-registry \
--disable-werror \
--disable-sim} \
--without-zlib \
--with-expat \
--with-python} \
--prefix=$HOME/rtems-dev/rtems/4.11

Building or1ksim

You can follow instructions here to build and configure OpenRISC simulator- or1ksim. Patch for building or1ksim from RSB is on its way to be commited soon.

 

References 

[1] Porting RTEMS to OpenRISC - Introduction 

[2] My github project repo (RTEMS).

[3] RTEMS or1k tool-chain status.

[4] HOWTO build or1k-rtems4.11 tool-chain.

RTEMS (or1k-rtems4.11-*) tool-chain for OpenRISC | Status Report - 25062014

Part of my GSoC project: Porting RTEMS to OpenRISC, I worked on hacking GNU tools to be able to build these tools for RTEMS targeting OpenRISC 1000 (AKA OR1K) architecture. These tools include: binutils, GCC and GDB. Besides, I had to work on Newlib port for OR1K since RTEMS depends on it. or1ksim (OR1K main emulator) is also part of the tool-chain. Currently, all the tools are working fine.

First I will list the status of each tool/program separately. After that (in the next few posts), we will come to the process of building the tool-chain. The following descriptions are concerned with some specific releases:

• binutils-2.24
• gcc-4.8.2
• newlib-2.1.0
• gdb-7.7
• or1ksim-github-head

binutils

There has a been a small patch for binutils to support building it for RTEMS. No big deal with it. Recently, supporting or1k for binutils has been upstreamed; so the next task for RTEMS is to push our patch for review and be upstream to binutils cvs repo.


Newlib

RTEMS depends on Newlib as a library instead of the big libgcc one. Mainly, only Newlib/newlib is necessary for RTEMS. libgloss is not used because RTEMS should provide all the functions and systems calls there. There are some issues regarding Licences and a possibility that the or1k Newlib port may not be upstreamed consequently. Hence, I had to revert back to an old patch to avoid such conflicts. Also, I did not include all of libgloss code. Moreover, I had to write setjmp.S from scratch for the same reason.


GCC

Most of GCC work was about configurations. Some other definitions had to be added to include the proper headers for RTEMS and avoid others from OR1K. libgloss libraries for BSPs provided by OR1K are no longer linked by default (since RTEMS does not use any of them). To test my Newlib port, I had to link bare-metal applications with libnosys.a. Eventually GCC is working fine with Newlib.


GDB

A minimal effort was spent on GDB. It should be built without or1ksim embedded as built-in library. Instead, the current method of debugging with GDB, is to remotely attach it to or1ksim emulator via RSP protocol.


OR1KSIM

The OpenRISC simulator is just used as is from github. Anyone who uses or1ksim should provide a configuration script for his or her target. This is the current sim.cfg script I use to run or1ksim RTEMS BSP. It should be added to your home directory or the current directory you run the simulator from.


RSB (RTEMS Source Builder)

In the time being, all of the previous tools (excluding or1ksim) can be built from RSB; it's the latest modern tool RTEMS uses to build all the tool-chain for targets that RTEMS support. Therefor, I had to add support to RSB to build rtems4.11-or1k-* tool-chain. The patch for such a purpose is committed, so any one can clone RSB and build the entire tool-chain from it. Building the tool-chain from RSB is the easiest way.

In the next few posts, I will introduce some tutorials HOWTO build the tool-chain both manually and from RSB.

References

[1] Porting RTEMS to OpenRISC - Introduction 
[2] My github project repo (RTEMS).
[3] RTEMS or1k tool-chain status.
[4] HOWTO build or1k-rtems4.11 tool-chain.
[5] or1k/rtems related stuff.
[6] tool-chain patches