xous-core/RELEASE-v0.9.md

Relase 0.9 notes

This release signals the stabilization of most Xous APIs; however, we reserve the right to make breaking changes, but with some justification. You could call this a "beta" release.

Notably, in 0.9, we have libstd integrated into Xous, and solidly intergated into several servers; thus this release is not backward compatible with 0.8 (and was never intended to be).

Aside from the introduction of libstd, few other breaking changes were implemented in the APIs. Thus, we refer you to the 0.8 release notes for examples of idiomatic ways to write code for Xous.

Major new features of 0.9

• Xous now targets riscv32-imac-uknown-xous-elf instead of riscv32-imac-unknown-none-elf.
  • cargo xtask, when run interactively, will offer to install the xous target.
  • Kernel debug primitives are accessible via the kernel console
  • GDB improvements
  • Improved MemoryRange API
  • Various stability improvements and major bug fixes (ELF loader bugs, stack pointer alignment, etc.)
  • Elimination of heapless crate
  • Transition from master->main for the default branch
• All hardware drivers are available in some form:
  • AES (using VexRiscV CPU extensions)
  • Audio Codec (low-level interface only, 8kHz rec/playback)
  • Curve25519 accelerator
  • SHA512 (based on Google's OpenTitan core)
  • JTAG self-introspection drivers
  • Real time Clock
  • FLASH memory writing
  • Suspend/Resume
  • Clock throttling when idle
  • TRNG upgraded with health monitoring and CSPRNG whitener
  • Upgrades to previous drivers (keyboard, graphics, etc.)
  • Wifi enhancements including SSID scanning and AP join commands
• Secured boot flow:
  • Signed gateware, loader and kernel
  • Compatible with BBRAM and eFuse keyed gateware images
  • Semi-automated BBRAM key burning
  • Self-provisioning of root keys (update and boot unlock keys)
  • Local re-encryption of gateware updates to a secret key known only to your device
  • Re-signing of loader/OS updates to protect code-at-rest
  • Detection of image "downgrade" attacks that use developer keys
  • Indication of downgrade through hardware-enforced hash marks on the status bar
• Enhanced graphical user interface primitives:
  • Modal dialog boxes
  • Menus
  • Progress bars
  • Text and password entry forms with input validators
  • Radio buttons
  • Check boxes
  • Notifications
  • Defacement of less secure items: random hashes on background areas; complicates phishing attacks that present fake UI elements
• Enforcement of delimited attack surfaces
  • xous-names can optionally enforce a fixed number of connections to a server
    • Once all the connections are occupied after boot, new connections are no longer possible
    • Developers must increment the connection count, specified inside the target server itself, when adding new resources that require server access
  • gam enforces a registry of all UX elements
    • Rogue processes cannot create new trusted UX resources
    • Developers must register their UX tokens in the gam inside tokens.rs
• Extended simulation support
  • Hosted mode performance improvements
  • Hosted mode now supports thread creation with std::thread::spawn()
• Improved emulation in Renode
  • Full emulation of ENGINE
  • Full emulation of SHA512 block
  • Initial support of emulation of EC
    • No COM-based inter-chip communication yet

New in 0.9.1

• modals server for a simple "Pure Rust" API for creating dialog boxes and getting user input. See the tests.rs file for some examples how to use the applcation calls.

Roadmap to 1.0

The items that are still missing before we can hit a 1.0 release include:

• PDDB (plausibly deniable database): a key/value store that is the equivalent of a "filesystem" for Xous
• Networking capabilities: a simple (think UDP-only) network stack
• Password changes in the rootkey context
• Post-boot loadable applications (currently we have a kernel, there is no notion of a separate "application" file from the kernel code base; although this might be a 1.1-release feature as it depends on the PDDB, which is a major item in and of itself)
• Lots of testing and bug fixes