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Truly independent web browser
3974cac148
The DT_RELR relocation is a relatively new relocation encoding designed to achieve space-efficient relative relocations in PIE programs. The description of the format is available here: https://groups.google.com/g/generic-abi/c/bX460iggiKg/m/Pi9aSwwABgAJ It works by using a bitmap to store the offsets which need to be relocated. Even entries are *address* entries: they contain an address (relative to the base of the executable) which needs to be relocated. Subsequent even entries are *bitmap* entries: "1" bits encode offsets (in word size increments) relative to the last address entry which need to be relocated. This is in contrast to the REL/RELA format, where each entry takes up 2/3 machine words. Certain kinds of relocations store useful data in that space (like the name of the referenced symbol), so not everything can be encoded in this format. But as position-independent executables and shared libraries tend to have a lot of relative relocations, a specialized encoding for them absolutely makes sense. The authors of the format suggest an overall 5-20% reduction in the file size of various programs. Due to our extensive use of dynamic linking and us not stripping debug info, relative relocations don't make up such a large portion of the binary's size, so the measurements will tend to skew to the lower side of the spectrum. The following measurements were made with the x86-64 Clang toolchain: - The kernel contains 290989 relocations. Enabling RELR decreased its size from 30 MiB to 23 MiB. - LibUnicodeData contains 190262 relocations, almost all of them relative. Its file size changed from 17 MiB to 13 MiB. - /bin/WebContent contains 1300 relocations, 66% of which are relative relocations. With RELR, its size changed from 832 KiB to 812 KiB. This change was inspired by the following blog post: https://maskray.me/blog/2021-10-31-relative-relocations-and-relr |
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| Meta | ||
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| Userland | ||
| .clang-format | ||
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SerenityOS
Graphical Unix-like operating system for x86 computers.
About
SerenityOS is a love letter to '90s user interfaces with a custom Unix-like core. It flatters with sincerity by stealing beautiful ideas from various other systems.
Roughly speaking, the goal is a marriage between the aesthetic of late-1990s productivity software and the power-user accessibility of late-2000s *nix. This is a system by us, for us, based on the things we like.
You can watch videos of the system being developed on YouTube:
Screenshot
Kernel features
- x86 (32-bit) and x86_64 (64-bit) kernel with pre-emptive multi-threading
- Hardware protections (SMEP, SMAP, UMIP, NX, WP, TSD, ...)
- IPv4 stack with ARP, TCP, UDP and ICMP protocols
- ext2 filesystem
- POSIX signals
- Purgeable memory
- /proc filesystem
- Pseudoterminals (with /dev/pts filesystem)
- Filesystem notifications
- CPU and memory profiling
- SoundBlaster 16 driver
- VMWare/QEMU mouse integration
System services
- Launch/session daemon (SystemServer)
- Compositing window server (WindowServer)
- Text console manager (TTYServer)
- DNS client (LookupServer)
- Network protocols server (RequestServer and WebSocket)
- Software-mixing sound daemon (AudioServer)
- Desktop notifications (NotificationServer)
- HTTP server (WebServer)
- Telnet server (TelnetServer)
- DHCP client (DHCPClient)
Libraries
- C++ templates and containers (AK)
- Event loop and utilities (LibCore)
- 2D graphics library (LibGfx)
- OpenGL 1.x compatible library (LibGL)
- GUI toolkit (LibGUI)
- Cross-process communication library (LibIPC)
- HTML/CSS engine (LibWeb)
- JavaScript engine (LibJS)
- Markdown (LibMarkdown)
- Audio (LibAudio)
- Digital Signal Processing/Synthesizer Chains (LibDSP)
- PCI database (LibPCIDB)
- Terminal emulation (LibVT)
- Out-of-process network protocol I/O (LibProtocol)
- Mathematical functions (LibM)
- ELF file handling (LibELF)
- POSIX threading (LibPthread)
- Higher-level threading (LibThreading)
- Transport Layer Security (LibTLS)
- HTTP and HTTPS (LibHTTP)
- IMAP (LibIMAP)
Userland features
- Unix-like libc and userland
- Shell with pipes and I/O redirection
- On-line help system (both terminal and GUI variants)
- Web browser (Browser)
- C++ IDE (HackStudio)
- Desktop synthesizer (Piano)
- E-mail client (Mail)
- Various desktop apps & games
- Color themes
How do I read the documentation?
Man pages are available online at man.serenityos.org. These pages are generated from the Markdown source files in Base/usr/share/man and updated automatically.
When running SerenityOS you can use man for the terminal interface, or help for the GUI.
How do I build and run this?
See the SerenityOS build instructions
Before opening an issue
Please see the issue policy.
FAQ: Frequently Asked Questions
Get in touch
Join our Discord server: SerenityOS Discord
Author
- Andreas Kling - awesomekling
Contributors
- Robin Burchell - rburchell
- Conrad Pankoff - deoxxa
- Sergey Bugaev - bugaevc
- Liav A - supercomputer7
- Linus Groh - linusg
- Ali Mohammad Pur - alimpfard
- Shannon Booth - shannonbooth
- Hüseyin ASLITÜRK - asliturk
- Matthew Olsson - mattco98
- Nico Weber - nico
- Brian Gianforcaro - bgianfo
- Ben Wiederhake - BenWiederhake
- Tom - tomuta
- Paul Scharnofske - asynts
- Itamar Shenhar - itamar8910
- Luke Wilde - Lubrsi
- Brendan Coles - bcoles
- Andrew Kaster - ADKaster
- thankyouverycool - thankyouverycool
- Idan Horowitz - IdanHo
- Gunnar Beutner - gunnarbeutner
- Tim Flynn - trflynn89
- Jean-Baptiste Boric - boricj
- Stephan Unverwerth - sunverwerth
- Max Wipfli - MaxWipfli
- Daniel Bertalan - BertalanD
- Jelle Raaijmakers - GMTA
- Sam Atkins - AtkinsSJ
- Tobias Christiansen - TobyAsE
- Lenny Maiorani - ldm5180
- sin-ack - sin-ack
- Jesse Buhagiar - Quaker762
- Peter Elliott - Petelliott
- Karol Kosek - krkk
- Mustafa Quraish - mustafaquraish
- David Tuin - davidot
- Leon Albrecht - Hendiadyoin1
- Tim Schumacher - timschumi
- Marcus Nilsson - metmo
- Gegga Thor - Xexxa
- kleines Filmröllchen - kleinesfilmroellchen
- Kenneth Myhra - kennethmyhra
(And many more!) The people listed above have landed more than 100 commits in the project. :^)
License
SerenityOS is licensed under a 2-clause BSD license.