Rust Userland Systems Sandbox

Purpose: Learn ownership, memory, and invariants in userland before writing a kernel.

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Wiki

Where most of the rust thoughts go Wiki

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What I Do

Follow Brown Rust Book: https://rust-book.cs.brown.edu/ch04-02-references-and-borrowing.html

Rust for rustasceans: rust for rustasceans

For each concept:

read → implement → test → fix → repeat

Also play Turing Complete for hardware intuition.

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Projects (Order Matters)

1. Memory map iterator
2. ELF header parser
3. Page table entry (bitflags)
4. Bump allocator
5. Slab allocator
6. Packet parser (Ethernet/IP)
7. Virtual file table (inode style)

If I can write these confidently → I’m ready for kernel subsystems.

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Testing Rule (Most Important Part)

Testing is the real skill I’m learning.

Kernel developers debug with invariants, not print statements.

Always keep a watcher running:

cargo install cargo-watch
cargo watch -x test

Workflow:

save file → tests run → fix immediately

Never continue while tests are red.

Run a single test:

cargo watch -x "test <name>"

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Commands I’ll Forget

Run all tests:

just test

Run one:

just t read_one

Auto-test on save:

just watch

Fast checks:

just check
just clippy

Deep debugging:

just miri

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What This Actually Teaches

• memory layout
• aliasing
• lifetimes
• binary parsing
• allocators
• resource tracking