QEMU VS systemd

My most-wanted QEMU feature: https://github.com/qemu/qemu/commit/a2260983c6553

Using `gic-version=3` on macOS you can now use more than 8 cores on ARM chips.

A better solution is just to write a plain ass shell script that tests if various C snippets compile.

https://github.com/oilshell/oil/blob/master/configure

https://github.com/oilshell/oil/blob/master/build/detect-pwe...

Not an unholy mix of m4, shell, and C, all in the same file.

---

These are the same style as a the configure scripts that Fabrice Bellard wrote for tcc and QEMU.

They are plain ass shell scripts, because he actually understands the code he writes.

https://github.com/qemu/qemu/blob/master/configure

https://github.com/TinyCC/tinycc/blob/mob/configure

OCaml’s configure script is also “normal”.

You don’t have to copy and paste thousands of lines of GNU stuff that you don’t understand.

(copy of lobste.rs comment)

Related:

A fast Pascal (Delphi) WebAssembly interpreter:

https://github.com/marat1961/wasm

WASM-4:

https://github.com/aduros/wasm4

Curated list of awesome things regarding WebAssembly (wasm) ecosystem:

https://github.com/mbasso/awesome-wasm

Also, it would be nice if there was a WASM (soft) CPU for QEMU, which (if it existed!) would go here:

https://github.com/qemu/qemu/tree/master/target

> architectural registers are always updated

In tiny code, the guest registers (global TCG variables) are stored in the host's registers until you either call an helper which can access the CPU state or you return (`git grep la_global_sync`). This is the reason why QEMU is not so terribly slow.

But after a check, this also happens when you access the guest memory address space! https://github.com/qemu/qemu/blob/master/include/tcg/tcg-opc... (TCG_OPF_SIDE_EFFECTS is what matters)

But still, in the end, it's the same problem. What QEMU does, can be done in LLVM too. You could probably be more efficient in LLVM by using the exception handling mechanism (invoke and friends) to only serialize back to memory when there's an actual exception, at the cost of higher register pressure. More or less what we do here: https://rev.ng/downloads/bar-2019-paper.pdf

Um, in case you don't know, UTM (based on QEMU) is out for quite a while.

Some of these tools include Oracle VM VirtualBox (that I've used since before the acquisition of Sun Microsystems by Oracle), VMWare Workstation Player, and QEMU, but last year, I found out about Multipass.

For C/C++ projects that use meson as the build system, there is an excellent way to manage dependencies:

https://mesonbuild.com/Wrapdb-projects.html

https://mesonbuild.com/Wrap-dependency-system-manual.html

meson will download and build the libraries automatically and give you a variable which you pass as a regular dependency into the built target:

https://github.com/qemu/qemu/tree/005ad32358f12fe9313a4a0191...

https://github.com/harfbuzz/harfbuzz/tree/main/subprojects

https://github.com/harfbuzz/harfbuzz/blob/37457412b3212463c5...

Or, if you're using proper operating systems, they're managed by the usual package manager, just like everything else.

For all the users of the Linux platform, QEMU is the VM that you should go for. This software comes without any price tag and works as an emulator of various machines with utmost ease and completion; the software uses dynamic translations to emulate hardware peripherals and enhances its overall performance. If you are using QEMU as a virtualizer, then it will function exactly like the host system (provided you have the right set of hardware).

In this tutorial, we set up macOS and Windows virtual machines on UTM, a macOS application that provides a GUI wrapper for QEMU, a powerful open-source emulator and virtualizer. UTM allows you to easily manage and run virtual machines without memorizing complex commands. It also has special handling for macOS, making it simpler to install compared to other virtual machine software.

Retrieve the archive containing the JBoss Web Server from the Red Hat Customer Portal and install the files on the system. Configure the Red Hat Enterprise Linux (RHEL) operating system including the users, groups, and the required setup files to enable JBoss Web Server as a systemd service. Ensure the required Java Virtual Machine is installed Fine-tune the configuration of the JBoss Web Server server, such as binding it to the appropriate interface and port. Deploy web applications along with enabling and starting the JBoss Web Server as a [systemd](https://www.freedesktop.org/wiki/Software/systemd/) service. Perform a health check to ensure that the deployed application is accessible.

A systemd-free fork from Debian Linux+GNU

Devuan is a fork of Debian GNU+Linux without systemd.

This post shows how to install and run Docker on Devuan, a systemd-free fork of Debian.

I built the dev env on Devuan GNU+Linux, a fork of Debian without systemd. It resembles my past trial on Artix Linux.

Devuan GNU+Linux is a fork of Debian without systemd and hence Snaps (Snapd). Even on it, it's easy to install Android Studio and start to develop Android mobile apps.

[root@rocky-8-lxc ~]# rpm -qf /etc/rc.d/rc.local systemd-239-68.el8_7.4.x86_64 [root@rocky-8-lxc ~]# rpm -qi systemd Name : systemd Version : 239 Release : 68.el8_7.4 Architecture: x86_64 Install Date: Fri 07 Apr 2023 02:11:42 AM UTC Group : Unspecified Size : 11306123 License : LGPLv2+ and MIT and GPLv2+ Signature : RSA/SHA256, Tue 21 Feb 2023 05:04:34 PM UTC, Key ID 15af5dac6d745a60 Source RPM : systemd-239-68.el8_7.4.src.rpm Build Date : Tue 21 Feb 2023 04:52:49 PM UTC Build Host : ord1-prod-x86build004.svc.aws.rockylinux.org Relocations : (not relocatable) Packager : [email protected] Vendor : Rocky URL : http://www.freedesktop.org/wiki/Software/systemd Summary : System and Service Manager Description : systemd is a system and service manager that runs as PID 1 and starts the rest of the system. It provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, keeps track of processes using Linux control groups, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic. systemd supports SysV and LSB init scripts and works as a replacement for sysvinit. Other parts of this package are a logging daemon, utilities to control basic system configuration like the hostname, date, locale, maintain a list of logged-in users, system accounts, runtime directories and settings, and daemons to manage simple network configuration, network time synchronization, log forwarding, and name resolution.