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1. Embed this notice
   Drew DeVault (drewdevault@fosstodon.org)'s status on Tuesday, 23-Apr-2024 18:02:02 JST Drew DeVault

   I needed a break from Real Work, so I'm speedrunning writing a Unix-ish operating system

   Day 3

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Tuesday, 23-Apr-2024 22:24:04 JST Drew DeVault

     in reply to

     • Shraddha

     @ezpy Hare

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     Shraddha (ezpy@fosstodon.org)'s status on Tuesday, 23-Apr-2024 22:24:06 JST Shraddha

     in reply to

     @drewdevault Writing in C?

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Tuesday, 23-Apr-2024 22:59:35 JST Drew DeVault

     in reply to

     The hacking shall continue until we are self hosting

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Tuesday, 23-Apr-2024 22:59:36 JST Drew DeVault

     in reply to

     Further day 3 progress

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 00:16:06 JST Drew DeVault

     in reply to

     Day 4

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 00:16:07 JST Drew DeVault

     in reply to

     End of day 3

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 00:16:07 JST Drew DeVault

     in reply to

     mood

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     R. L. Dane :debian: :openbsd: (rl_dane@fosstodon.org)'s status on Thursday, 25-Apr-2024 00:29:20 JST R. L. Dane :debian: :openbsd:

     in reply to

     @drewdevault

     Lemme guess, "just a little hobby project, won't ever be as big as MINIX, only supports AT harddisks right now because that's all you have?" 😂

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 19:52:44 JST Drew DeVault

     in reply to

     End of day 4: ext4 works but needs to be integrated into the filesystem abstraction (which also needs to be fleshed out)

     Maybe VFS tomorrow?

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 19:52:44 JST Drew DeVault

     in reply to

     Starting to get lwext4 rigged into the Bunnix filesystem abstraction

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 19:52:44 JST Drew DeVault

     in reply to

     Did anyone else think inodes were black magic when they first got into Unix

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 19:52:45 JST Drew DeVault

     in reply to

     It can read files from the Linux install on my laptop :D

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     Haelwenn /элвэн/ :triskell: (lanodan@queer.hacktivis.me)'s status on Thursday, 25-Apr-2024 19:55:36 JST Haelwenn /элвэн/ :triskell:

     in reply to
     @drewdevault Heh, not sure when I learned of inodes existence… definitely was a long time ago like 15+ years.
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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 22:34:14 JST Drew DeVault

     in reply to

     Work progresses on integrating ext4 with the Bunnix filesystem API

     This screenshot brought to you by fs::* rather than lwext4::*

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Thursday, 25-Apr-2024 22:34:14 JST Drew DeVault

     in reply to

     I have a (shitty) VFS

     That's probably it for day 5, I have other things to do today 🙂

     Haelwenn /элвэн/ :triskell: likes this.
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     Drew DeVault (drewdevault@fosstodon.org)'s status on Friday, 26-Apr-2024 16:35:54 JST Drew DeVault

     in reply to

     What's probably next is fleshing out the VFS a bit, then getting to userspace and implementing a few syscalls

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Friday, 26-Apr-2024 16:35:54 JST Drew DeVault

     in reply to

     Day 7, taking a break to hang out with a friend who's in town, more to come tomorrow

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Friday, 26-Apr-2024 20:48:37 JST Drew DeVault

     in reply to

     • BIG KRIMPIN

     @bigkrimpin I ain't no fuckin monarchist

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     BIG KRIMPIN (bigkrimpin@mstdn.party)'s status on Friday, 26-Apr-2024 20:48:45 JST BIG KRIMPIN

     in reply to

     @drewdevault but Drew, tomorrow is kingsday, you can't miss out on kingsday!

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:05 JST Drew DeVault

     in reply to

     Hey my waitqueue implementation worked on the first try

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:06 JST Drew DeVault

     in reply to

     (no, I have not set up kernel preemption yet, there are no locks in the kernel and interrupts are always disabled when the kernel is running; as a consequence of that I can only cooperatively context switch the kernel right now)

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:07 JST Drew DeVault

     in reply to

     So today is refactoring, particularly for scheduling and file management.

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:07 JST Drew DeVault

     in reply to

     Nice, that's the bulk of the scheduler refactoring done. No pretty screenshot since there are no user-visible changes, but the short of it is that we can context switch to and from the kernel rather than only to and from userspace.

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:08 JST Drew DeVault

     in reply to

     Signals are hard. Might do some refactoring instead, particularly with respect to files

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:09 JST Drew DeVault

     in reply to

     ayy

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:09 JST Drew DeVault

     in reply to

     Summary of work up to day 10:

     * AHCI driver
     * MBR and GPT partitions
     * ext4
     * VFS
     * Userspace
     * Preemptive multitasking
     * Syscalls: readv, writev, lseek, close, mmap, munmap, mprotect, fork, execve

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:09 JST Drew DeVault

     in reply to

     Next up is signals and waitpid? Or openat et al. We shall see.

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:10 JST Drew DeVault

     in reply to

     Okay, reorganized the source tree to make a lot more sense before we move any further into userspace. Took some inspiration from the BSD layouts, since I intend to ship kernel and userspace as one cohesive project.

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:10 JST Drew DeVault

     in reply to

     Day 10 is getting fork working (and preemptive multitasking)

     Getting there.

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:10 JST Drew DeVault

     in reply to

     There we go!

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:10 JST Drew DeVault

     in reply to

     exec works, but there's still some kind of bug in fork+exec

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:11 JST Drew DeVault

     in reply to

     Okay, now you don't have to take my word for it

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:11 JST Drew DeVault

     in reply to

     Day 8 was all about getting userspace online. We are loading ELF programs, jumping into userspace, and we have working interrupts and syscalls

     Day 9 will start implementing more useful syscalls and fleshing out I/O

   • Embed this notice
     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:11 JST Drew DeVault

     in reply to

     There we go. That's probably all for today.

   • Embed this notice
     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:11 JST Drew DeVault

     in reply to

     I confess that I rushed into userspace without a plan, so I have a bit of a mess to figure out once I decide how to actually structure the project properly.

     But that aside, I implemented a handful of syscalls today, notably readv, write, and mmap (MAP_ANON only, for allocations)

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:12 JST Drew DeVault

     in reply to

     ✓ ELF loader

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:12 JST Drew DeVault

     in reply to

     ✓ Userspace

     No user I/O yet though so you have to take my word for it

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 21:10:13 JST Drew DeVault

     in reply to

     Day 8: let's write a System-V loader and get to userspace

     also: don't write a USB driver don't write a USB driver don't write a USB driver

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Wednesday, 01-May-2024 22:13:32 JST Drew DeVault

     in reply to

     open syscall works, though it's kind of shitty

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     Drew DeVault (drewdevault@fosstodon.org)'s status on Friday, 03-May-2024 23:03:20 JST Drew DeVault

     in reply to

     End of day 11:

     New syscalls: getpid, getppid, openat

     Scheduler refactored, AHCI driver yields while waiting on I/O and handles errors from the block device properly

     Some filesystem refactoring done: inodes moved around in the codebase, fs::walk can terminate at the last entry (e.g. for creat(2) or mkdir, etc)

     Next up is probably one of the following:

     * Implement console device files
     * finish openat (i.e. flags like O_CREAT, enforce RDONLY etc)
     * inode lifecycle
     * signals/waitpid