[LINUX] Cross-compiling for Raspberry Pi Zero on Debian-Try using shared libraries

Overview

Run a C language program compiled on Debain on a Raspberry Pi Zero. I want to create an environment where I can use shared libraries. For the time being, let's use libusb or libjpeg.

Continuing from Starting cross-compilation for Raspberry Pi Zero on Ubuntu, I am trying again with Debian as the host machine (for a reason later).

environment

Host: Debian 10.6.0 <Virtual Box 6.1 <WIndows10 Target: Raspberry Pi Zero WH

procedure

Installing the compiler for ARM

$ sudo apt install crossbuild-essential-armel

Last time tried installing g ++-arm-linux-gnueabi, but it seems to be included in crossbuild-essential-armel So I will install this. After all, gcc is used, so it doesn't make much difference.

Install shared libraries

Add architecture,

$ sudo dpkg --add-architecture armel

Editing sources.list. I will add the repository referenced by apt.

$ sudo nano /etc/apt/sources.list

Add the following at the bottom of sources.list. For armel, also refer to ftp.jp.debian.org.

/etc/apt/sources.list

deb [arch=armel] http://ftp.jp.debian.org/debian buster main

Update and install the library. You can get the library for armel by adding: armel.

$ sudo apt update
$ sudo apt install libusb-dev:armel
$ sudo apt install libjpeg-dev:armel

Maybe if the package is published for Ubuntu armel, I think I can do the same with Ubuntu by adding it to sources.list, but I found that I published the armel package for Ubuntu not.

試しにUbuntuでftp.jp.debian.org/debianを追加してみましたが、「署名されてません」みたいなエラーが出てインストールできませんでした。そりゃそうか。

Is there a way to forcefully install it? (I was able to bring in .deb and install it, but I gave up because the dependency became difficult)

Build

Click here for the program to build this time.

testUsbLib.c

#include <stdio.h>
#include <usb.h>

int main()
{
    printf("call usb_init()\n");
    usb_init();
    printf("OK\n");

    return 0;
}

A useless program that just calls usb_init (). It doesn't clean up usb_init () (did I have to do something ...?).

Build here.

$ arm-linux-gnueabi-gcc -march=armv6 testUsbLib.c -o testUsbLib_armv6 -lusb

Try to make it work

If you can build successfully above, copy the generated testUsbLib_armv6 to a suitable folder on Raspberry Pi Zero,

$ testUsbLib_armv6
call usb_init()
OK

And it works like this. Nothing happens, but ...

Summary

Since libusb has few dependencies, it can be quite good even if you get the .deb file and install it manually, but libjpeg etc. have many dependencies, and I gave up because there were too many steps manually. This method installed it including the dependencies, so it seems to have worked.

By the way, I have confirmed the operation of libtiff in addition to libusb and libjpeg by this method.

Also, if anyone knows if the same method can be used on Ubuntu (whether there is a package for armel published, etc.), please let me know.

Postscript

I wrote the following article.

• Cross-compile for Raspberry Pi Zero on Debian-Try to make your own shared library