Andrew Huang (), a well-known free hardware activist and award-winning , an open platform", designed to create concepts for new mobile devices. Similar to how the Raspberry Pi and Arduino allow you to create devices for the Internet of things, Precursor aims to provide the ability to design and build various mobile devices with your own hands to solve your problems.
Unlike other projects, Precursor offers enthusiasts not just a board, but a ready-made prototype of a portable device with an aluminum case measuring 69 x 138 x 7.2 mm, an LCD screen (336 × 536), a battery (1100 mAh Li-Ion), a miniature keyboard, loudspeaker, vibration motor, accelerometer and gyroscope. The compute module does not come with a ready-made processor, but with a software-defined SoC based on the Xilinx XC7S50 FPGA, on the basis of which emulation of a 32-bit RISC-V CPU operating at 100MHz is organized. At the same time, there are no restrictions on emulation of other hardware components, for example, the operation of various processors, from 6502 and Z-80 to AVR and ARM, as well as sound chips and various controllers, can be emulated. The board includes 16 MB SRAM, 128 MB Flash, Wi-Fi Silicon Labs WF200C, USB type C, SPI, I²C, GPIO.
Of the security-related features, the presence of two hardware pseudo-random number generators is noted. Interestingly, the device basically comes without a built-in microphone - it is understood that sound reception is possible only if the headset is explicitly connected, and if the headset is turned off, it is physically impossible to organize eavesdropping, even if the device software has been compromised.
The chip for wireless communication (Wi-Fi) is hardware isolated from the rest of the platform and operates in a separate environment. A lockable case, separate RTC for integrity tracking, standby motion monitoring (always on accelerometer and gyroscope) are also used to protect against unauthorized access. There is also a chain of self-destruction and instant clearing of all data, activated using an AES key.
FHDL is used to describe hardware components (Fragmented Hardware Description Language) based on Python. Migen is part of the framework , which provides the infrastructure for creating electronic circuits. Precursor based reference SoC prepared with FPGA and LiteX , including 100 MHz CPU VexRISC-V RV32IMAC, as well as an embedded controller
Betrusted-EC with 18 MHz LiteX VexRISC-V RV32I core.
The Betrusted SoC provides a built-in set of cryptographic primitives such as a pseudo-random number generator, AES-128, -192, -256 with ECB, CBC and CTR modes, SHA-2 and SHA-512, based on elliptic curves Curve25519. The crypto engine is written in SystemVerilog and is based on crypto cores from the project .
Precursor is positioned as a prototyping and verification platform, while Betrusted is one of the off-the-shelf mobile devices based on Precursor. Since traditional enclaves used for isolated storage of crypto keys do not protect against high-level attacks, such as collecting passwords using keyloggers or accessing messages through screenshots, Betrusted adds user interaction elements to the enclave implementation (, Human-Computer Interaction) to ensure that human-readable sensitive data is never stored, shown, or transmitted outside of a secure device.
Betrusted does not try to replace the mobile phone, but only forms a secure enclave with auditable input and output. For example, an external smartphone can be used over Wi-Fi as an untrusted data link, but the transmitted encrypted messages are typed only on the built-in keyboard of the Betrusted device, and the received messages are displayed only on the built-in screen.
All Precursor and Betrusted components are open source and available for modification and experimentation under license requiring all derivative works to be opened under the same license. including open and full project documentation , finished implementation и (). Models available for 3D printing of the body. Also developing in the form of open projects and specialized Xous is based on a microkernel.
Source: opennet.ru