Updates in June 2019

This post gives an overview of the recent updates to the Writing an OS in Rust blog and the used libraries and tools.

My focus this month was to finish the Heap Allocation post, on which I had been working since March. I originally wanted to include a section about different allocator designs (bump, linked list, slab, …) and how to implement them, but I decided to split it out into a separate post because it became much too long. I try to release this half-done post soon.

Apart from the new post, there were some minor updates to the x86_64, bootloader and cargo-xbuild crates. The following gives a short overview of notable changes to the different projects.

blog_os

• Use misspell tool to look for common typos
• New post about heap allocation

x86_64

• Add ring-3 flag to GDT descriptor by @mark-i-m (released as version 0.7.1)
• Add bochs magic breakpoint, read instruction pointer, inline instructions by @64

bootloader

• Make the physical memory offset configurable through a BOOTLOADER_PHYSICAL_MEMORY_OFFSET environment variable
• Use a stripped copy of the kernel binary (debug info removed) to reduce load times (released as version 0.6.1)

cargo-xbuild

• Document the XBUILD_SYSROOT_PATH environment variable
• Fix incorrect joining of paths that caused some problems on Windows