Connor Wood
f79424aeac
- Implemented a global variable, ACPI_TABLE, behind a mutex, which contains the ACPI information pertinent to the rest of the kernel, currently solely containing a pointer to the FADT. - Split device initialization into two categories - "core" devices, such as the PIC and local APIC, necessary for initializing the rest of the kernel, and "non-core" devices such as serial and RTC, which are to be initialized last. - Checked for the presence of the century register, and consequentially read from, in the RTC code, now factored into the date calculation. The location of the register is pulled from the "century" field in the FADT. - Modified page unmapping in the ACPI code, such that any tables to be stored globally (currently only the FADT) are not unmapped after reading, such that they can be stored in globally accessible pointers without causing page faults.
kernel
A collaborative effort to rewrite the kernel with focus on correctness and code quality.
Why?
The kernel code was getting increasingly messy to the point where only the original writer would be able to find and fix bugs. Fortunately, the kernel of Redox is relatively small and such a project is estimated to take only a few months.
What?
The aims of the new kernel should be clear in their order:
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Correctness: Above anything else, the kernel should be correct. No hacks, despite how the tiny cool shortcuts might seem, it gives severe backslash later on. Keep it correct and well-written.
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Readability and documentation: The code quality should be high, with that follows a detailed documentation, including both API docs (on every item!) and careful comments for anything non-trivial.
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Performance: If you can, go for it.
Guidelines
A rotten house is built on a rotten fundament.
Don't fool yourself. You are likely not getting back to the ugly code. Write it the right way first time, and make sure you only move on when it's done right.
Comments
Do not hesitate to put comments all over the place.
Documentation
Every public item should contain API documentation.
Debug assertions
Abusing debug assertions is a wonderful way to catch bugs, and it is very much encouraged.
Statical checking
Rust provides a lot of type-system features which can be used to create wonderful safe abstractions, and you should use them whenever you get the chance.
Unsafety should be avoided, and if it is triggered only under some addition insert an assertion. Despite this being a kernel, we prefer kernel panics over security vulnerabilities.
If the condition is (or should be) unreachable, but if not upheld, leading to UB, put an assertion in the start of the function.
Be gentle
Don't just write as much code as you can as quick as possible. Take your time and be careful.
Commits
Use descriptive commits. One way to force yourself to do that is to not pass the
-m flag, which will make your editor pop up, so that you can conviniently
write long commit messages.