Install fpc on Raspberry with Gentoo

This article applies to Raspberry Pi only.

See also: Multiplatform Programming Guide

Introduction

This brief guide describes the steps I took to install the fpc free pascal compiler on my raspberry with gentoo. I could not find guides to install free pascal (not Lazarus) on a raspberry with gentoo, so, I want to share my experience. I followed several guides found on the net, especially this: http://www.michellcomputing.co.uk/blog/2012/11/lazarus-on-the-raspberry-pi I also searched (and found) help in both free pascal and gentoo forums and, in both cases, I received very valuable aid.

If you are interested to the result, here you can find and download the SD image for your raspberry. https://sourceforge.net/projects/pastoo/?source=navbar

What kind of install?

Below I describe the method I adopted to get a linux distro with these features:

• Minimum linux installation
• No X server, no desktop manager
• Software installed: ssh, subversion and git
• The latest stable version of the official fpc compiler (2.6.4)
• additional and isolated (from the official 2.6.4) trunk fpc compiler (2.7.1) installed from source downloaded with subversion and compiled on raspberry.

I chose the gentoo distro and, of course, the installation does not is the subject of this guide also because the official Gentoo documentation is very good.

Install the latest version of fpc from repository

Whatever linux distro, it rarely happens the packages fpc/lazarus are aligned with the latest stable release. In my case, the last official fpc release is 2.6.4 (the only officially needed to compile the trunk), while in gentoo repositories I found fpc 2.6.2.

I strongly recommend the use of official packages from the distro. Always check the repository for the release that you need, in the case of gentoo:

1) update the list of packages:

   # emerge --sync 

2) search for fpc compiler:

   # emerge --search fpc 

In case you find the correct version to compile the trunk (in this case 2.6.4), install it with no doubts:

   # emerge dev-lang/fpc 

and then jump to the section "Installation of subversion."

In case there is not ... proceed manually according to the following section.

Manually install the latest version of fpc

We must search for the arm fpc release. We have different places to search for, starting from following links:

• ftp://ftp.freepascal.org/pub/fpc/dist/2.6.4/arm-linux/
• http://sourceforge.net/projects/freepascal/files/Linux/2.6.4/

Always verify both of them, they are not updated at the same time.

Download the tarball and we can prepare to install (as root):

   # su
   # mkdir /usr/local/fpc
   # cd /usr/local/fpc
   # wget -O fpc-2.6.4.arm-linux.tar http://sourceforge.net/projects/freepascal/files/Linux/2.6.4/fpc-2.6.4.arm-linux.tar/download
   # tar xvf fpc-2.6.4.arm-linux.tar
   # cd fpc-2.6.4.arm-linux
   # ./install.sh

You will be asked for some questions which usually we can answer pressing the ENTER key, howewer I have done the installation as follows:

• Installation folder : /usr/local
• documentation not installed
• examples not installed

If you have installed in folder /usr/local, you can verify the presence of fpc :

   # ls /usr/local/lib/fpc

and you will see its subfolders :

• 2.6.4
• lexyacc

Also try to run the compiler :

   # fpc
   Free Pascal Compiler version 2.6.4 [2014/03/21] for arm
   Copyright (c) 1993-2014 by Florian Klaempfl and others
   /usr/local/lib/fpc/2.6.4/ppcarm...

Installing subversion

Subversion is one of those programs that you will definitely find in the repository, whatever linux distro you have chosen. In the case of gentoo:

   # emerge dev-vcs/subversion

On a raspberry with gentoo, emerge subversion is challenging process. It will take a while.

Downloading fpc trunk sources

Now we need to download the sources of fpc trunk.

   # mkdir /usr/local/fpc/2.7.1
   # cd /usr/local/fpc/2.7.1
   # svn co http://svn.freepascal.org/svn/fpc/trunk trunk
   # svn export --force trunk trunktmp
   # cd trunktmp

Before building

There are a few things to check:

1) ld-linux.so from the description in the man pages (man ld-linux.so): "The programs ld.so and ld-linux.so * find and load the shared libraries needed by a program, prepare the program to run, and then run it." You have to find this .so, whatever it's called and wherever it is located

   # find /lib/ld-*
   /lib/ld-linux-armhf.so.3

Remember this fullpath as we must pass it as a parameter.

2) crtbegin.o and crtend.o These files are also needed to proceed with the construction of the compiler, so you have to find them; just look for one of the two:

   # find /usr/lib -name crtbegin.o         
   /usr/lib/gcc/armv6j-hardfloat-linux-gnueabi/4.7.3/crtbegin.o

Another fullpath to remember

Build the compiler

Run the following commands in sequence:

   # cd /usr/local/fpc/trunktmp
   # make all OPT='-gl -O3p3' -j 8 FPMAKEOPT="-o -Fo/usr/lib/gcc/armv6j-hardfloat-linux-gnueabi/4.7.3" FPC=/usr/local/lib/fpc/2.6.4/ppcarm OPT=-FL/lib/ld-2.17.so OPT=-Fo/usr/lib/gcc/armv6j-hardfloat-linux-gnueabi/4.7.3

here you have to wait a bit

   # make install PP=compiler/ppcarm PREFIX=/usr/local -j 8 FPMAKEOPT="-o -Fo/usr/lib/gcc/armv6j-hardfloat-linux-gnueabi/4.7.3"

Now, instead of creating a symbolic link in / usr / bin to be able to use the new compiler, I want to keep in use two compilers (such as mentioned at the beginning) and I want them isolated. This is why I do not create the link, but later, I will create a script.

We can instal sources

   # make install sourceinstall PREFIX=/usr/local

Now we need to create a configuration file so that it does not conflict with the one already present in /etc (related to the compiler 2.6.4). I want to place the fpc.cfg file in the “etc” subfolder inside the compiler folder. First of all, we can backup the files in /etc. Now we can create the etc subfolder:

   # mkdir /usr/local/lib/fpc/2.7.1/etc
   # /usr/local/lib/fpc/2.7.1/samplecfg /usr/local/lib/fpc/2.7.1 /usr/local/lib/fpc/2.7.1/etc

At this point I create a script to launch the new compiler passing the configuration file as parameter:

   # nano /usr/local/bin/fpc271.sh 

and there I copy the following content:

   #!/bin/sh
   # This script execute the fpc trunk compiler 
   
   if [ $# -eq 0 ]; then
      /usr/local/lib/fpc/2.7.1/ppcarm
   else
      /usr/local/lib/fpc/2.7.1/ppcarm -n @/usr/local/lib/fpc/2.7.1/etc/fpc.cfg ""$@""
   fi

At this point, to compile with the 2.6.4 release, simply invoke compiler with the classic name fpc:

   # fpc [options]

To invoke the 2.7.1 compiler:

   # fpc271.sh [options]