Baochip-1x: What It Is, Why I'm Doing It Now, and How It Came About
10 hours ago
- #MemoryManagement
- #OpenSourceHardware
- #RISC-V
- The Baochip-1x includes a Memory Management Unit (MMU), a feature not commonly found in microcontrollers of its class, enabling secure, loadable apps with virtual memory space.
- MMUs, dating back to the 1960s, are a proven technology for memory protection and are essential for modern operating systems like Linux, BSD, or Mach.
- Despite newer memory protection technologies like CHERI, PMPs, and MPUs, the MMU remains a pragmatic choice due to its composability and benefits like swap memory.
- The absence of MMUs in embedded SoCs traces back to the ARM7TDMI core's efficiency in the 1990s, a convention that persists despite advancements in transistor density.
- ARM's strategy to exclude MMUs from low-cost M-series cores to protect high-end A-series sales has led to the use of proprietary MPUs, limiting innovation.
- Open architecture specifications like RISC-V and implementations such as Vexriscv allow for the inclusion of MMUs in SoCs, challenging proprietary conventions.
- The Baochip-1x is part of a partially-open RTL SoC, with closed-source components limited to non-computational parts like AXI bus frameworks and USB PHYs.
- A partnership with Crossbar, Inc. enabled the Baochip-1x's development by utilizing unused space on a 22 nm chip, avoiding venture capital or personal wealth funding.
- The Baochip-1x aims to foster an open-source community, supporting a Rust-based OS called Xous and encouraging the development of secure, trustable open-source futures.
- Production of Baochip-1x is underway, with initial chips available through a pre-order campaign, aiming to build a community around open-source hardware security.