Re: How to use the L4 Microkernel with a FreeBSD userland.

From: Mario Marietto <marietto2008_at_gmail.com>
Date: Sun, 11 Feb 2024 21:20:31 UTC
I will do it as soon as I get all the necessary tools to turn on the
Raspberry Pi 4b. I was thinking that L4 worked like the old project
coLinux,where Linux ran as a list of processes under WIndows. In my sick
mind I'd thought that L4 allows FreeBSD to run as a list of processes with
the L4 microkernel itself on "top" of it. Do you know if something like
this exists ?



On Sun, Feb 11, 2024 at 9:01 PM Mark Millard <marklmi@yahoo.com> wrote:

> [Only replying to what I've subscribed to --and I dropped
> Warner as well.]
>
> On Feb 11, 2024, at 11:43, Mario Marietto <marietto2008@gmail.com> wrote:
>
> > ok. But what does this mean ? That I can use whatever Linux distro I
> want ? Or even the FreeBSD world ?
>
> Only to build L4Re.
>
> The LR4e built will not contain any Linux userland materials,
> nor any FreeBSD userland materials. LR4e has its own userland
> materials that will be present instead.
>
> http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/
>
> already contains pre-built .elf and .uimage files Why not use one
> of those on the RPi4B?
>
> By size (larger), the most complete ones for the RPi4B seem to be
> (both formats):
>
>
> http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/bootstrap_vm-multi_rpi4.elf
>
> http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/bootstrap_vm-multi_rpi4.uimage
>
>
> http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/bootstrap_vm-basic_rpi4.elf
>
> http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/bootstrap_vm-basic_rpi4.uimage
>
>
> > On Sun, Feb 11, 2024 at 7:59 PM Mark Millard <marklmi@yahoo.com> wrote:
> >
> >
> > On Feb 11, 2024, at 05:44, Mario Marietto <marietto2008@gmail.com>
> wrote:
> >
> > > I'm trying to understand how to use the L4 Microkernel with a FreeBSD
> userland. I've asked the same to a L4 developer,but he told me that he does
> not know FreeBSD,so I'm here to ask the same question. First of all I'm
> sure that it can be done,because it is written clearly on their website :
> > >
> > >
> > > http://os.inf.tu-dresden.de/L4Re/download/snapshots/
> > >
> > >
> > > on the section :
> > > Host system requirements
> > > The host system shall be a 64bit-based system with a recent Linux
> distribution installed and at least 2GB of free disk space.
> > > All necessary tools required by the build are available from the
> provided packages of the Linux distributions, including cross compilers.
> But there are also other cross compiler packages available (see below). You
> might want to run make check_build_tools in the src/l4 directory to verify
> the common tools are installed.
> > > You are free to use any Linux distribution you like, or even BSDs or
> any of its derivatives. But then you should know the game. Especially tool
> versions should be recent, as installed on the listed distributions below.
> > > We are confident that the snapshot works on the following
> distributions:
> > >     • Debian 11 or later
> > >     • Ubuntu 22.04 or later
> > >
> > > Let's say I want to use the L4 microkernel + FreeBSD 14 on my
> Raspberry Pi 4,the first step I did was to build L4Re for the Rpi,according
> with this instructions :
> > >
> > >
> > > http://os.inf.tu-dresden.de/L4Re/rpi.html
> > >
> > > This is the log file of the compilation,that hasn't given any  error :
> > >
> > >
> > > https://pastebin.ubuntu.com/p/6SwN2mpJBM/
> > >
> > >
> > > Or I could have taken a pre built image of the L4 microkernel here :
> > >
> > >
> > > http://os.inf.tu-dresden.de/download/snapshots/pre-built-images/arm64/
> > >
> > >
> > >
> > > At this point the tutorial says that I should use a Linux distro. They
> suggest the official distro for the Raspberry Pi 4,that's RaspBian. But I
> don't want to use Linux as a userland,I want to use FreeBSD. The question
> now is : what should I do to achieve that goal ? How can I link the L4
> microkernel with the ubldr bootloader of FreeBSD ? Or should I link it to
> the kernel of FreeBSD ? Can someone explain to me the missing step ? thanks.
> >
> > QUOTING the "Configuring yourself" section:
> > The make setup step configures predefined setups for both the L4Re
> microkernel (Fiasco) and the L4Re user-level software, and connects both
> together so the images for the target system can be built.
> > END QUOTE
> >
> > So L4Re has its own user-level software, not just a kernel. There is no
> use of a Linux or FreeBSD user-level software
> > when L4Re is booted. (They are just used for building.)
> >
> > "The host system" is just a host for building the L4Re parts and
> assembling the image from the parts. The "Pulling it together" section is
> about combining the parts (including the microkernel and the user-level
> software) to make the overall image that does not include Linux or FreeBSD
> code.
>
>
> ===
> Mark Millard
> marklmi at yahoo.com
>
>

-- 
Mario.