Day 6 was about Exceptions and handling those Exceptions in the kernel. In RISC-V the CPU first checks `medeleg` register to determine which operation mode should handle the exception. In our case `U-mode/S-mode` is already handled by `OpenSBI`. Then, the CPU saves states into various `CSRs`. `stvec` register is set to `pc` then the exception is handled using the handler. Then `sret` is called to resume execution from the point where exception occurred. The `handle_trap` function reads why the exception occurred and triggers the kernel panic. Which was implemented yesterday.

Perfect topic for today because early morning I was shown why It was a stupid decision to do something, then at afternoon I got into a bike accident. Though it was minor with no injuries to both parties except some scratches on the bikes. It could have caused huge consequences. Then I did another mistake and then another. PANIC! It is day 5. Implementing panic was very easy, it is implemented as a macro because if we defined it as a function it would have printed the `__LINE__` and `__FILE__` where `PANIC` is defined and not where it is called. And to halt the kernel it uses a `while true` loop which goes on infinitely.

To make a useful kernel we require it to perform tasks like setting a memory chunk to zero, or copying the memory from a source address to destination address. It may have to understand what a boolean is or what NULL is. So, for that we require the "C Standard Library" and hence we need to implement it (or the functions it contains as abstractions to commonly used functions). For this, in day 4 I utilized `clang`'s internal C library as well as resorted to writing the functions all by myself.

As the days progress the journey is getting more fun and interesting. It was the part where actual text was going to be printed. It was a kernel `hello-world`. Day 3 focused on printing characters on the console by talking to SBI finally implementing `putchar` and eventually `printf`.

The actual development of OS started with making the build script `run.sh` in bash to setup and launch a `qemu` RISC-V virtual machine with `OpenSBI` as bios for QEMU. Then a linker script `kernel.ld` was made and a basic kernel process `kernel.c` was written. Finally, the build script was updated to include compiler and execution commands and flags to properly boot the kernel. Day 2 focused on writing a basic starting process of a kernel and running it in a virtual machine.

I have set up the environment required to run RISC-V 64 toolchain using `QEMU`. Installed a `debian` RISC-V 64 `iso` and set it up to my liking with `autologin` and proper terminal emulation and `sudo`. I then installed `gcc`, `gdb` and `neovim` for writing and compiling programs. Details of what happened on Day 1 is tracked using `git` with `codeberg` as a remote. I have decided to use Operating System in 1000 Lines as the learning material because it was featured as a beginner level learning material in github:riscv/learn.

I want to learn systems programming and I thought why not go with the open source one which is currency in development. So, I chose the RISC-V architecture. That way if I decide to keep pursuing it, I can grow along with the ISA slowly catching up to it. I want to keep a streak by posting here every day about what I learn. Let's hope it goes well.

_Don't rely on anyone to do what you can do for yourself._ `Angela Del Toro, Daredevil: Born Again, 2025` I don't mean it in a dangerous sense, like how she does in the series. But think it in a more general sense. It's a good advice.

I have tears in my eyes, hearing that ingenuity is dead, but not fully dead. First she just shocks everyone by living more than we anticipated her to, and now she is dead because she can no longer do what she went there to do. But, still alive that she's doing work that she wasn't even assigned to do, with broken wings and muddy eyes.

So, Scar was suffering from depression, after all he had the pressure of becoming a king, and yet he wasn't trained, cared, taught, loved....(As described in the story.). Why did Mufasa not understand and forgive him and let him be the part of the family (While he was once lost and alone too.)? Spoiler Alert: He wanted the villain to its sequel.

Until next time, _Hate is when you are hurt seeing them happy._ `The Adventures of Scientiac, 2025`

Using linux coming from windows is like, talking in a different language. You try to use your grammar with their words (making it an accent) and you feel difficult communicating. And saying linux is harder to use than windows is like speaking is harder than speaking . Live in the place for some time and instead of worrying about the language, you think about the services, products and lifestyle the place offers. * * * ## Webmentions Have you written a response to this? Let me know the URL, Or, you can send your response via mail:`[email protected]` Send Webmention Mastodon scientiac A Computer Engineering student who loves FOSS and is learning about privacy, the Internet and languages writing about the things he does. I can't think of things to write on a footer. So, just imagine something yourself. RSS | research::map | Source Code All articles are usable under CC BY-SA 4.0.

I once called myself an optimist. But since negativity has started seeping in, it has become very difficult to focus on the positives, not even for people who ( is, are ) would have been loved if it wasn't for that negativity ( pride, ego, narcisicim, misogeny, misandry, .... ). I won't trust me for how I describe people, and won't trust anyone but myself to really know one. And neither should you. I suggest you create a picture of a person on your own and not from someone else's description or bias. This won't change the people who I say are are bad to not be bad, but verifying it is essential. Thank you.

How are people supposed to trust you when all you give are excuses. When are you gonna learn that your actions have consequences, consequences that affect other people.

Charlie Puth remains my favourite.

Indieweb is such a cool place. And the fact that you have webrings and webmentions makes it the most open and custom social media. The possibility of interactions and replies adds beauty with convenience to this unique form of communication. I just love it. Thanks @aaronpk for the tests.