▲ 12 r/osdev
BIOS or UEFI?
I just want to ask and see who and what choses.
I personally chose UEFI for compatibility with modern PCs (90%+ of market)
u/Brilliant_Trifle1915 — 12 hours ago
r/osdev
▲ 25 r/osdev
why do most hobby os devs boot with BIOS?
i don't understand what's the point of developing os if you can't run it on modern hardware?
u/NoTutor4458 — 18 hours ago
Modern computing operating systems have made massive strides in accessibility, offering robust screen readers and navigation tools for blind and visually impaired users. However, a critical barrier remains completely unaddressed at the pre-boot level: UEFI and BIOS firmware interfaces.
When a machine requires troubleshooting, low-level configuration, security key management, or operating system reinstallation, the interface relies entirely on visual, pointer-driven, or unannounced text menus with zero native screen reader or text-to-speech support. This effectively locks users out of managing their own physical hardwareFrom an engineering perspective, modern UEFI environments are capable of running complex code and graphical drivers. Why hasn**'**t firmware standardization (like UEFI specifications) incorporated basic accessibility APIs or screen reader support into pre-boot environments? How can open-source firmware projects or hardware vendors tackle this gap?
u/obaida2026 — 11 hours ago
Syscall monitor
I would like to share my Linux Syscall Monitor project with you. It's a Linux process monitoring tool written in C that uses "ptrace" to observe system calls and generate behavioral reports.
I welcome any feedback or criticism—whether it's about the code .
u/cdtrmnbaell — 1 day ago
▲ 13 r/osdev
How does kernel interfaces work on (unix) systems?
Hi,
I simply can't rotate it right in my head, if i make an app with say socket() how does it translate in to hooking it to the kernel when already in use?
Usually include, is a part of the program statically and making a struct for an interface as usual, does it copy it over compared to a zero copy arch?
u/Yha_Boiii — 1 day ago
Vibecoding a clean-slate, non-POSIX operating system ecosystem from scratch (OpenWindows)
Hi everyone,
I'm 13 years old. For a long time, I’ve been interested in the concept of custom "Windows distributions" (Deborah OS, Blue Hat Windows, Windows Earth) acting as modern, open-source alternatives to Linux distros.
While ReactOS exists as an open-source NT alternative, its strict focus on 100% legacy binary compatibility forces it to replicate the technical debt and design flaws of old Windows versions. To build something better, I've been using LLMs to help me write the freestanding C99 and NASM assembly code for a clean-slate, high-performance foundation that strips away that legacy baggage.
The project is called OpenWindows. It is a modern, object-oriented kernel framework with zero POSIX/Unix heritage, compiled strictly with -std=c99 -nostdlib -ffreestanding.
To completely bypass the complexities and bugs associated with UTF-16 surrogate pairs and standard Unicode normalization tables, I engineered an alternative character mapping and serialization protocol:
- SuperUnicode (SUCS): A 31-bit character encoding address space with a built-in System Control Plane for inline rendering markers.
- SUTF Transports: Stream serialization protocols ranging from a 1-to-6 byte variable format (SUTF-8) down to a 4-bit hexadecimal format (SUTF-4) for raw serial text debugging, and a 2-bit symbol format (SUTF-2) for thread IPC.
- SuperUnicode Extended (ExtSUCS): An unbounded 64-bit encoding featuring fixed-width vector transports (SUTF-128/256/512) optimized for direct SSE/AVX register alignment and SIMD string operations.
.suf(SuperUnicode Font): A custom vector font format mapped directly to SUCS address spaces rather than legacy Unicode index tables (WIP).
The build pipeline is automated via Python scripts and CMake, and validated using a headless QEMU integration testing harness. The current repository stack includes:
- Modular Bootloader (MBL): A multi-stage x86 BIOS bootloader with a custom 32-bit Protected Mode to 16-bit Real Mode trampoline (
_bios_tramp) to handle BIOS disk calls natively in C. - OpenWindows Storage: A freestanding filesystem suite containing native drive storage (
libowfs.a) and portable external media storage (libusfs.a) with ChaCha20 encryption and an explicit cryptographic key-slot shredding protocol. - SuperUnicode & SUTF: The foundational C99 library implementing the Base SUCS character mapping, SUTF stream packing, and the 64-bit Extended mode casting logic.
- VIP (Volume Indexing Protocol): A unified volume and partition indexing engine designed to replace traditional mount maps with SUTF-8 string identifiers. The VIP architecture (including the FVIP B+ tree indexing and UniVIP external flags) is currently WIP.
- BANcode Registry: A kernel damage-control system mapping critical panic states directly to 15 hardware security trap handlers at
0x7FFFFFF0using unique SUCS codepoints (WIP).
I am currently working on the basic layout for the OpenWindows Essential Drivers repository (WIP) to handle NVMe/SATA storage blocks, PS/2 scancode filtering, and VBE graphics blitting without relying on standard monolithic abstractions.
The base libraries are dual-licensed under MIT and Apache 2.0 so anyone can implement their own independent "Windows distributions/distros" (sometimes referred to as OpenWindows distros) on top of these clean-slate kernel layers.
Let me know your thoughts on managing low-level bare-metal constraints and structural memory alignment using this kind of workflow.
u/big-user — 1 day ago
Testing the nexsOS UI (NOTE: Use of ai in source code)
Warning: This project was built using AI, mostly with free plans, but also with the support of Claude Code. It's not the nature of my post to pretend I created anything here; I was really just the supervisor. That said, the huge nature (at least from my point of view) of this project, and my limited financial resources have forced me to constantly think and learn, and continue to do so, so I consider myself at a lower level in terms of coding skills than most of the people who are part of this community, and I love seeing how each of us makes mistakes and tries to patch them.
Nexsos is therefore a project born to allow me to learn in an interactive and gradual way what all the aspects of a computer are, and to allow me to do so in an informal way, and with gradual discovery. Nexsos is not intended to be a product or a boast, it is in all respects a Frankenstein born to test how much human ignorance and curiosity mixed with the algorithmic knowledge of an LLM can give life to something that works.
On the technical side, the purpose of NexsOS1 is simple: to separate the kernel from the userspace to allow me to learn the C language on my API without blowing everyone up, and at the same time to make my C library simple and readable in a single file. The graphics protocol had to be designed in the same way. The easy choices would have been two: to provide a basic environment for GNU Utilis and compile an X server/Wayland, or to rewrite the graphical interface from scratch. I stupidly chose the second one and with all the problems that come with it, for example, for now the compositor is in the kernel and shadows without hardware vector accelerators make the framerate explode. The good thing, however, is that the rendering of the applications is done in userland, so having SMP support makes graphical applications easier.
That said, why this video? At some point in our journey, we should ask ourselves how useful we really are to others. I have always seen AI as a very powerful tool, but perhaps we tend to forget what it means for us, I do not have the actual skills to build a functional and working system on two architectures with multitasking and a working SMP, but if I do not have the actual skills to do this and I can do it, what can these tools do in the hands of large companies that do not want to share the code? Even if I call myself ignorant, perhaps I am ignorant about coding, here we all know how the GNU project and the GPL project were born, I do not know what the members of this thread think about it and I do not even know if it is the right thread, after all, guys, we also know how these LLMs were trained on the effort of all software developers, is it right to privatize public knowledge? As far as I am concerned, the only thing I could really do is exploit the knowledge of AI itself to put together and build something free, so I do not know how you want to define NexsOS, I do not care, the important thing for me is that it is free and that anyone can in turn steal code from within it.
NOTE: If anyone would like to look at the code and has any questions about missing references or licenses, I'd be happy to update the published code. Any criticism is welcome.
NOTE2: lua still doesn't pass all the tests, even though the IDE works and also the job controls of my shell seem ok (I didn't show them in this video), the exec daemon is ok, but I'm having problems with the initialization of the venv for pid.
u/shsh-1312 — 1 day ago
I wrote an AArch64 quine as part of my AArch64/x86-64/RV64 learning journey
I'm learning assembly so I can eventually create my own IR/compiler/language.
The code is frankly ugly. I hope you find it (or my incompetence) funny:
```AArch64
.global \_start
.section .text
_start:
stp x29, x30, \[sp, #-32\]!
mov x29, sp
str x20, \[sp, #16\]
mov x13, sp
ldr x9, =0x75206e6576617265
ldr x10, =0x0a726f776f207577
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20333c20656e6975
ldr x10, =0x687465696e6e6977
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x72657a2e203a6666
ldr x10, =0x712f2f0a3538206f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x37206e67696c612e
ldr x10, =0x757473657065720a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6f69746365732e09
ldr x10, =0x090a7373622e206e
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c70735b202c30
ldr x10, =0x0a22215d36312d23
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7473745c6e5c3032
ldr x10, =0x3178202c39782070
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3032303230327830
ldr x10, =0x3032303230323032
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x646c745c6e5c3032
ldr x10, =0x3d202c3031782072
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3032303230327830
ldr x10, =0x3032303230323032
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6c745c6e5c222069
ldr x10, =0x3d202c3978207264
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d6574657065720a
ldr x10, =0x696373612e203a70
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6e6f69746365732e
ldr x10, =0x617461646f722e20
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x36783023202c3931
ldr x10, =0x090a746572090a36
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x65747962660a7465
ldr x10, =0x7720766f6d090a3a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c39317720766f
ldr x10, =0x72090a3536783023
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x650a746572090a34
ldr x10, =0x6d090a3a65747962
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7720766f6d090a3a
ldr x10, =0x36783023202c3931
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x72090a3336783023
ldr x10, =0x65747962640a7465
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d090a3a65747962
ldr x10, =0x202c39317720766f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x36783023202c3931
ldr x10, =0x630a746572090a32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x65747962620a7465
ldr x10, =0x7720766f6d090a3a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c39317720766f
ldr x10, =0x72090a3136783023
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x610a746572090a39
ldr x10, =0x6d090a3a65747962
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7720766f6d090a3a
ldr x10, =0x33783023202c3931
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a746572090a3833
ldr x10, =0x65747962656e696e
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20766f6d090a3a65
ldr x10, =0x783023202c393177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a746572090a3733
ldr x10, =0x7479626874676965
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20766f6d090a3a65
ldr x10, =0x783023202c393177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a746572090a3633
ldr x10, =0x7479626e65766573
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20766f6d090a3a65
ldr x10, =0x783023202c393177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6572090a35337830
ldr x10, =0x7479627869730a74
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6f6d090a3a657479
ldr x10, =0x23202c3931772076
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x72090a3433783023
ldr x10, =0x62657669660a7465
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d090a3a65747962
ldr x10, =0x202c39317720766f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a333378302320
ldr x10, =0x72756f660a746572
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a3a6574796265
ldr x10, =0x2c39317720766f6d
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a323378302320
ldr x10, =0x657268740a746572
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a3a657479626f
ldr x10, =0x2c39317720766f6d
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3133783023202c39
ldr x10, =0x77740a746572090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3a65747962656e6f
ldr x10, =0x317720766f6d090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x783023202c393177
ldr x10, =0x0a746572090a3033
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7479626f72657a0a
ldr x10, =0x20766f6d090a3a65
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2e62090a66307830
ldr x10, =0x6574796266207165
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d63090a65747962
ldr x10, =0x23202c3831772070
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6530783023202c38
ldr x10, =0x652071652e62090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6574796264207165
ldr x10, =0x317720706d63090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x23202c3831772070
ldr x10, =0x2e62090a64307830
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x632071652e62090a
ldr x10, =0x6d63090a65747962
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x317720706d63090a
ldr x10, =0x6330783023202c38
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2e62090a62307830
ldr x10, =0x6574796262207165
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d63090a65747962
ldr x10, =0x23202c3831772070
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6130783023202c38
ldr x10, =0x612071652e62090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x65747962656e696e
ldr x10, =0x317720706d63090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x30783023202c3831
ldr x10, =0x2071652e62090a39
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7479626874676965
ldr x10, =0x7720706d63090a65
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x30783023202c3831
ldr x10, =0x2071652e62090a38
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7479626e65766573
ldr x10, =0x7720706d63090a65
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x30783023202c3831
ldr x10, =0x2071652e62090a37
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7479627869732071
ldr x10, =0x7720706d63090a65
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3023202c38317720
ldr x10, =0x652e62090a363078
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6265766966207165
ldr x10, =0x706d63090a657479
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x23202c3831772070
ldr x10, =0x2e62090a35307830
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x72756f662071652e
ldr x10, =0x6d63090a65747962
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c38317720706d
ldr x10, =0x62090a3430783023
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x657268742071652e
ldr x10, =0x63090a6574796265
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c38317720706d
ldr x10, =0x62090a3330783023
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x77742071652e6209
ldr x10, =0x63090a657479626f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x38317720706d6309
ldr x10, =0x0a3230783023202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2071652e62090a31
ldr x10, =0x0a65747962656e6f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7720706d63090a65
ldr x10, =0x30783023202c3831
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x71652e62090a3030
ldr x10, =0x7479626f72657a20
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20706d63090a3a65
ldr x10, =0x783023202c383177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x62696e0a30232063
ldr x10, =0x7479626f74656c62
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c387820766f6d09
ldr x10, =0x7673090a33392320
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x766f6d090a323323
ldr x10, =0x0a3023202c307820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x303378202c393278
ldr x10, =0x202c5d70735b202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3123202c70735b20
ldr x10, =0x2070646c090a5d36
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a3a6666757473
ldr x10, =0x2c3032782072646c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x637673090a323131
ldr x10, =0x746978650a302320
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7820627573090a31
ldr x10, =0x23202c3278202c32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x782072736c090a32
ldr x10, =0x23202c3278202c32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c32782062757309
ldr x10, =0x3278202c31327820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x78202c3178206464
ldr x10, =0x0a33313123202c31
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x317820766f6d090a
ldr x10, =0x61090a323278202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6f6d090a34362320
ldr x10, =0x3123202c30782076
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a3a7473616c746e
ldr x10, =0x2c387820766f6d09
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x77646e6173207467
ldr x10, =0x6972700a31686369
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c37317820706d63
ldr x10, =0x2e62090a30327820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a353823202c32
ldr x10, =0x090a302320637673
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6675747365706572
ldr x10, =0x7820766f6d090a66
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6c090a3123202c30
ldr x10, =0x3d202c3178207264
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3623202c38782076
ldr x10, =0x7820766f6d090a34
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x35317820766f6d09
ldr x10, =0x6f6d090a3023202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x78202c3231782064
ldr x10, =0x0a333423202c3231
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c323178202c3231
ldr x10, =0x6461090a39322320
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x676e69746e697270
ldr x10, =0x7820627573090a3a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x68636977646e6173
ldr x10, =0x656d757365720a32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3123202c35317820
ldr x10, =0x20746c2e62090a36
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c353178202c3531
ldr x10, =0x706d63090a312320
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c5d3231785b20
ldr x10, =0x7820646461090a31
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x73090a657479626f
ldr x10, =0x2c39317720627274
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6c62090a66307830
ldr x10, =0x74656c6262696e20
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x38317720646e6109
ldr x10, =0x23202c363177202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x785b202c39317720
ldr x10, =0x0a3123202c5d3231
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x79626f74656c6262
ldr x10, =0x62727473090a6574
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x23202c3831772c20
ldr x10, =0x696e206c62090a34
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a3066783023202c
ldr x10, =0x3831772072736c09
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20646e61090a312d
ldr x10, =0x363177202c383177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c363177206272
ldr x10, =0x23202c5d3731785b
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x313278202c313278
ldr x10, =0x646c090a3123202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x68636977646e6173
ldr x10, =0x20646461090a3a32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x78202c3231782062
ldr x10, =0x0a363423202c3231
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x77646e617320746c
ldr x10, =0x7573090a31686369
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x35317820706d6309
ldr x10, =0x2e62090a3823202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c353178206464
ldr x10, =0x0a3123202c353178
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3231785b202c3931
ldr x10, =0x61090a3123202c5d
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x657479626f74656c
ldr x10, =0x772062727473090a
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a6630783023202c
ldr x10, =0x6262696e206c6209
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20646e61090a3123
ldr x10, =0x363177202c383177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c39317720627274
ldr x10, =0x202c5d3231785b20
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x74656c6262696e20
ldr x10, =0x73090a657479626f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3831772c20383177
ldr x10, =0x6c62090a3423202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x66783023202c3631
ldr x10, =0x2072736c090a2030
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6e61090a312d2320
ldr x10, =0x77202c3831772064
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x363177206272646c
ldr x10, =0x2c5d3731785b202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x78202c3132782064
ldr x10, =0x090a3123202c3132
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6977646e61730a30
ldr x10, =0x6461090a3a316863
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x313123202c327820
ldr x10, =0x2320637673090a32
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c317820766f6d
ldr x10, =0x766f6d090a343178
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20766f6d090a3436
ldr x10, =0x090a3123202c3078
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d090a3a74737269
ldr x10, =0x23202c387820766f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x23202c343178202c
ldr x10, =0x66746e6972700a31
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a3123202c333178
ldr x10, =0x3032782062757309
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x73090a3123202c34
ldr x10, =0x202c373178206275
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x627573090a312320
ldr x10, =0x3178202c32327820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7820627573090a30
ldr x10, =0x2c333178202c3132
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6f6d090a33342320
ldr x10, =0x23202c3531782076
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7820646461090a35
ldr x10, =0x2c323178202c3231
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c32317820627573
ldr x10, =0x3823202c32317820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7264617465736572
ldr x10, =0x090a3a7365737365
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x657264616f6c2074
ldr x10, =0x0a66667574736570
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x202c35317820706d
ldr x10, =0x6c2e62090a353823
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3178202c35317820
ldr x10, =0x63090a3123202c35
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c5d3231785b202c
ldr x10, =0x646461090a312320
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x090a3123202c5d31
ldr x10, =0x3631772062727473
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x206272646c090a3a
ldr x10, =0x31785b202c363177
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x7264616f6c0a3023
ldr x10, =0x6666757473657065
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6d090a6666757473
ldr x10, =0x202c35317820766f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6c3a202c32317820
ldr x10, =0x657065723a32316f
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x61090a6666757473
ldr x10, =0x2c32317820206464
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x782070726461090a
ldr x10, =0x65706572202c3231
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3a32316f6c3a202c
ldr x10, =0x706d657465706572
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2020646461090a70
ldr x10, =0x313178202c313178
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x2c31317820707264
ldr x10, =0x6d65746570657220
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x317820766f6d090a
ldr x10, =0x61090a7073202c34
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x766f6d090a5d3631
ldr x10, =0x7073202c33317820
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x3032782072747309
ldr x10, =0x23202c70735b202c
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x20766f6d090a215d
ldr x10, =0x0a7073202c393278
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x5b202c303378202c
ldr x10, =0x32332d23202c7073
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x0a3a74726174735f
ldr x10, =0x3932782070747309
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6f69746365732e09
ldr x10, =0x0a747865742e206e
stp x9, x10, \[sp, #-16\]!
ldr x9, =0x6c61626f6c672e09
ldr x10, =0x0a74726174735f20
stp x9, x10, \[sp, #-16\]!
mov x14, sp
adrp x11, repetemp
add x11, x11, :lo12:repetemp
adrp x12, repestuff
add x12, x12, :lo12:repestuff
mov x15, #0
loadrepestuff:
ldrb w16, \[x11\], #1
strb w16, \[x12\], #1
add x15, x15, #1
cmp x15, #85
b.lt loadrepestuff
resetadresses:
sub x12, x12, #85
add x12, x12, #43
mov x15, #0
sub x21, x13, #1
sub x22, x14, #1
sub x17, x13, #1
sub x20, x14, #1
printfirst:
mov x8, #64
mov x0, #1
mov x1, x14
mov x2, #112
svc #0
sandwich1:
add x21, x21, #1
ldrb w16, \[x17\], #-1
and w18, w16, #0xf0
lsr w18 ,w18, #4
bl nibbletobyte
strb w19, \[x12\], #1
and w18, w16, #0x0f
bl nibbletobyte
strb w19, \[x12\], #1
add x15, x15, #1
cmp x15, #8
b.lt sandwich1
sub x12, x12, #46
sandwich2:
add x21, x21, #1
ldrb w16, \[x17\], #-1
and w18, w16, #0xf0
lsr w18 ,w18, #4
bl nibbletobyte
strb w19, \[x12\], #1
and w18, w16, #0x0f
bl nibbletobyte
strb w19, \[x12\], 1
add x15, x15, #1
cmp x15, #16
b.lt sandwich2
resumeprinting:
sub x12, x12, #29
add x12, x12, #43
mov x15, #0
mov x8, #64
mov x0, #1
ldr x1, =repestuff
mov x2, #85
svc #0
cmp x17, x20
b.gt sandwich1
printlast:
mov x8, #64
mov x0, #1
mov x1, x22
add x1, x1, #113
sub x2, x21, x22
lsr x2, x2, #1
sub x2, x2, #112
svc #0
exitstuff:
ldr x20, \[sp, #16\]
ldp x29, x30, \[sp\], #32
mov x0, #0
mov x8, #93
svc #0
nibbletobyte:
cmp w18, #0x00
b.eq zerobyte
cmp w18, #0x01
b.eq onebyte
cmp w18, #0x02
b.eq twobyte
cmp w18, #0x03
b.eq threebyte
cmp w18, #0x04
b.eq fourbyte
cmp w18, #0x05
b.eq fivebyte
cmp w18, #0x06
b.eq sixbyte
cmp w18, #0x07
b.eq sevenbyte
cmp w18, #0x08
b.eq eigthbyte
cmp w18, #0x09
b.eq ninebyte
cmp w18, #0x0a
b.eq abyte
cmp w18, #0x0b
b.eq bbyte
cmp w18, #0x0c
b.eq cbyte
cmp w18, #0x0d
b.eq dbyte
cmp w18, #0x0e
b.eq ebyte
cmp w18, #0x0f
b.eq fbyte
zerobyte:
mov w19, #0x30
ret
onebyte:
mov w19, #0x31
ret
twobyte:
mov w19, #0x32
ret
threebyte:
mov w19, #0x33
ret
fourbyte:
mov w19, #0x34
ret
fivebyte:
mov w19, #0x35
ret
sixbyte:
mov w19, #0x36
ret
sevenbyte:
mov w19, #0x37
ret
eigthbyte:
mov w19, #0x38
ret
ninebyte:
mov w19, #0x39
ret
abyte:
mov w19, #0x61
ret
bbyte:
mov w19, #0x62
ret
cbyte:
mov w19, #0x63
ret
dbyte:
mov w19, #0x64
ret
ebyte:
mov w19, #0x65
ret
fbyte:
mov w19, #0x66
ret
.section .rodata
repetemp: .ascii "\n\tldr x9, =0x2020202020202020\n\tldr x10, =0x2020202020202020\n\tstp x9, x10, [sp, #-16]!"
.section .bss
.align 7
repestuff: .zero 85
//quine <3 winnietheraven uwu owor```
u/Zealousideal_Pain_88 — 1 day ago
Ethereal's new taskbar and desktop UI looks amazing (no AI used + from-scratch)
Ethereal's new UI for version 2.0.0 is coming along great! Here you can see the new taskbar, start menu, and desktop icons (+ a new wallpaper)
Neutron powers everything you see here (minus the Terminal and About Ethereal box, those are todo). The wallpaper chooser, the file explorer, hell even the desktop icons. It provides a mostly fluent and good looking desktop experience.
Total feature list:
- Built on a custom UI framework known as Neutron which uses a widget-tree model to layout and draw while remaining fully resizable and clean
- The new taskbar, with support for listing applications. Celestial sends events to the "root window" (there can only be one) for new windows, focus events, etc. The taskbar even has this awesome fade animation that plays
- The background icons are (as obvious) incomplete. They have this really weird box blur shadow thing I cobbled together from random codepieces to give them an outline. Otherwise, white text would look like garbage
- Over 6 wallpapers have been created by the lovely artist
- The start menu supports sub-folders (once separate icons are made, it will be more visible - for now Demos is the sub-folder here, containing the demos for Ethereal)
- Menus for Alt-Tab keybinds, an application quick-launch menu, as well as other things are fully supported.
- A minimal (possibly TUI) text editor and (definitely GUI) image viewer are planned for 2.0.
Both of these are still in beta so they haven't been pushed yet, but they are almost ready to be.
As always - Ethereal is a from-scratch x86_64 UNIX-like monolithic modular kernel and contains no artificial intelligence code. The repo is licensed under BSD 3-clause and can be found here:
u/Professional_Cow3969 — 2 days ago
▲ 16 r/osdev
How do keyboard interrupts work?
I learnt keyboard polling and understood how it works. But I can't seem to understand keyboard interrupts. I know how it works, but I don't know how to implement it in a C kernel. Can someone pls help me? I'm just starting out OS dev
u/Fun-Entertainer-1053 — 2 days ago
My 1986 RTOS is now preemptively multitasking on a Raspberry Pi Pico — and it made me question whether I need an RTOS
A while ago, I posted here about getting the first CPU-independent parts of CHARM-II, an RTOS I originally developed in 1986, running on a Raspberry Pi Pico.
Previous post:
The First Original CHARM-II Kernel Code Running on Raspberry Pi Pico
https://www.reddit.com/r/osdev/s/gthHF6vBrl
At that point, there were no timer interrupts or real context switches yet.
Now those parts are working too.
Six tasks are running with independent stacks. An RP2040 hardware timer interrupt calls the CHARM-II tick and scheduling logic, and the actual context switch is done with PendSV on the Cortex-M0+.
I also ported a six-task demo I had previously reconstructed on POSIX. Six tasks move around three tracks, with a critical zone protected by a CHARM-II queue used as a semaphore. On the Pico, the tasks are now actually being preempted by the hardware timer rather than cooperatively yielding.
So technically, this is pretty much the milestone I wanted to reach.
But getting it working gave me another question.
The original targets in the 1980s were processors such as the 68000 and 80186. With the CPU resources available at the time, an RTOS was a useful way to organize multiple concurrent real-time activities.
But what if we had had something with the performance and price of a Raspberry Pi Pico back then?
For many systems I work with today, especially UI-oriented embedded systems, if all the required processing comfortably fits within one frame, a superloop plus interrupts may actually be simpler.
Once everything becomes preemptive, I also have to start thinking about reentrancy, synchronization and shared state in existing libraries. That cost is starting to look more significant to me than it did when I started this experiment.
Yesterday I visited someone who has built a home railway simulator using real railway controls connected to a Windows PC through Pico, ESP32 and Arduino boards. We talked about this, and he said something very simple:
“If one Pico isn't fast enough, add another Pico.”
That hadn't really occurred to me.
In the 1980s, adding another CPU was a fairly serious architectural decision. With today's inexpensive MCUs, distributing the work across two or three processors can be a perfectly ordinary option.
So after spending quite a bit of effort getting a 40-year-old RTOS to perform real preemptive context switching on modern hardware, I'm becoming more interested in a different question:
Where would you draw the line today between an RTOS, a superloop/event-driven design, interrupts, and simply distributing the work across multiple cheap MCUs?
I'm also thinking that when I publish the modernized version of CHARM-II, I may deliberately keep it very small — just enough task scheduling, queues, timer ticks and context switching to run this six-task demo.
Then I can use it as one reference implementation and try implementing the same behavior without an RTOS.
u/noborutkhs — 3 days ago
What do you think about this command prompt app design for my os
I’ve live streamed the making of it, so I dare anyone to say it’s AI ;) haha
Here is the link : https://twitch.tv/devcmar
Though the output does not probably show up on the livestream because it is running in another tty
u/devcmar — 3 days ago
▲ 15 r/osdev
How do I start on OS develpment?
Hi there! For the past year, I've been wondering how computers work, and I wanted to get started with OS development. However, I'm feeling quite lost—I don't really know where to start or what I should learn first. If you could give me some advice on how to get started, I'd really appreciate it!
I have experience with C and C++, as well as a general understanding of how low-level computing works.
u/Bastartd — 2 days ago
Submit your projects to be shown off in my weekly OSDev newsletter (RSS + website exists)
I decided to start a small news site dedicated to stories about OSDev published every friday, starting next week. Please submit your projects!
SUBMIT: https://forms.gle/7ZRNJ9RGSjnp3rx5A
RSS: https://news.thatosdeveloper.us/feed.xml
Website: https://news.thatosdeveloper.us
NOTE: The base site is still being revamped as its based on an old jekyll theme and of course many things are subject to change. Also for now comments use Disqus though this may be changed at some point in time.
EDIT: Though a mailing list will be setup to send out emails every Sunday at 0900 (9AM). And posts will happen at least once a week though more may happen over time.
u/TheNullDeref — 3 days ago
▲ 7 r/osdev
What're some good tutorials or websites to learn how to build an OS in UEFI?
I learnt how to create a BIOS OS using the osdev website. Are there any good sources or something to learn how to build a UEFI kernel?
Edit: thx guys, I learnt a lot
u/Fun-Entertainer-1053 — 3 days ago
▲ 29 r/osdev
I'm creating my own operating system because I still haven't finished it
I recently added a background, even though it's not a pure VGA textmode, but it's okay, I'm constantly developing it and I see flaws, I see a lot of placeholders that are still there. And I would like to ask you to give a star in the repository because it motivates us to continue working intensively with it, and at the moment the main development is on the unstable branch.
https://github.com/CTRL-F-0rg3/TrangorgeOS
I know the flaws of what we have now, so I will fix them as they come, but I would also be happy to receive help with developing the system in various areas, as we still have a lot of work to do.
u/CtrlF0rge — 4 days ago
What I've learned the last few weeks
Sorry about my abscense, I've been on my vacation/holiday.
I've done a lot of learning the last few weeks. Here are the highlights
- I'm completely redoing my memory management. I'm working on a Physical Memory Manager (PMM), AND a virtual memory manager (VMM). Completely redoing how I deal with paging. I came to realize that except for reserved and my video physical memory, I really don't care where it gets assigned. Also, again except for video and reserved physical memory, it can all be swapable.
My PMM keeps track of the following items: a) does the memory exist; b) is it available, for example I define my video memory as not available, it is allocated early on, and I don't want the PMM deallocating it; c) Is it allocated to a virtual address yet; d) in concert with c, is it sharable (multi-allocated); e) is it swappable, I don't want to swap video and reserved memory for example.
My VMM keeps track of the following: a) is it swapped out (future); b) is it read only, such as my kernel code and .rodata; c) is it kernel memory, not sure if I really need this, but I had spare bits, I might want to use this in my swapping algorithm; d) is it shared.
Much of what I had in my paging .c file, has moved to my PMM and VMM. I'm hoping to finish this this week.
Once I have those three areas done, I will redo my heap and then make my github code public.
I'd also like some advice, I have two things I'm thinking about doing next: 1) adding threading, I'm not actually sure what I'd do with it right now as I don't really have a block device to save swapped blocks to; 2) adding support for user space, this would allow me to put things like most of my video and my shell into user space, this would also justify doing threading next; or 3) adding support for SATA, this would justify threading (for swap), but I might want to put it in user space then it would be restartable.
As always your opinions are always welcome.
Hopefully this will be useful for the people searching after me.
Thanks for reading!
u/compgeek38400 — 3 days ago
Darwin raspberry pi3 now runs many basic system commands
Progress on the pi3 port of Darwin continues. Libc, pthread , libdispatch are built. User accounts properly work. While dylib isn't ready yet but statically linked simple utilities now run off of the SD card.
u/anurodhp — 4 days ago
Custom OS made from Scratch in C
Hi there , I recently made a 32-bit x86 operating system built from scratch in freestanding C and NASM.
It includes:
graphical desktop
window manager
networking stack
e1000 and RTL8139 drivers
TLS 1.3 client
HTTP/HTTPS
web browser
HTML rendering
desktop applications
games
If you want to check it out, it’s here: github.com/pefia/PefiaOS
u/IndependenceNew6308 — 4 days ago