RISC OS 5 TiBox

An emulator for the RISC OS Dual Core A15 OMAP5 machine, based on the Texas Instruments AM5728 SoC (dual Cortex-A15).

Status: Work in progress. See Roadmap below.

RISC OS booted to the colour desktop on the emulated AM5728, with the Task Manager and iconbar.

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Overview

This project emulates the hardware of the Dual Core A15 OMAP5 motherboard sufficiently to boot and run RISC OS. It models the AM5728 SoC peripherals, memory map, and core behaviour as a software target.

The AM5728 is a publicly documented part. All hardware facts used in this emulator — register addresses, bit-field layouts, memory maps, reset values, and peripheral behaviour — are derived from publicly available Texas Instruments sources and from observation of real hardware behaviour.

Hardware target

Item	Detail
SoC	Texas Instruments AM5728 (Sitara)
CPU	2× ARM Cortex-A15
Machine	Dual Core A15 OMAP5 (RISC OS)
References	TI public AM5728 datasheet & Technical Reference Manual

Building

# TODO: fill in your build steps

Running

# TODO: fill in invocation + ROM image instructions

You must supply your own RISC OS ROM image. None is distributed with this project.

Roadmap

RISC OS boots all the way to the colour desktop and is interactive. Status of the emulated subsystems:

Working

• CPU cores — 2× Cortex-A15
• Memory map & DDR
• Interrupt controller (GIC)
• Clocks / PRCM (DPLL/APLL lock)
• UART (OMAP 16550)
• Timers (DMTIMER) & OS tick
• CMOS / RTC over I2C
• Display / framebuffer — colour desktop, hardware mouse pointer, idle dirty-skip
• Storage — SATA (AHCI) and SD/MMC
• USB / input — xHCI keyboard and mouse
• Networking — CPSW Ethernet over SLIRP user-mode NAT
• HostFS — host ↔ RISC OS file bridge
• GC320 — 2D graphics acceleration
• Boots to the RISC OS desktop

In progress / experimental

• [~] Audio — McASP3 + TLV320 codec (opt-in via TITANIUM_SOUND=1)
• [~] Second core (SMP/AMP) — secondary A15 released via PSCI CPU_ON; RISC OS SMP HAL entries and ROM build in progress

Planned

• AUX_CORE_BOOT secondary-core release for SMP on real AM5728 silicon
• Promote audio to on-by-default once the model is fully stable

Documentation & provenance

This emulator is an independent, clean-code-style implementation. It is written from an understanding of how the AM5728 hardware behaves, not by transcribing any third-party document. No Copyrighted Documentation or Diagrams was Uploaded or Included during this work.

• Register and peripheral definitions are annotated, where practical, with citations to TI's publicly available AM5728 datasheet and Technical Reference Manual.
• No proprietary or licence-restricted documentation is reproduced, redistributed, or included in this repository — neither the documents themselves nor their text, diagrams, or tables.
• No RISC OS ROM, firmware, or other copyrighted binary is distributed here.

If you believe any content in this repository infringes your rights, please open an issue and it will be addressed promptly.

Legal

• "RISC OS" is the property of its respective owner. This project is not affiliated with or endorsed by them.
• "Sitara" and "AM5728" are trademarks of Texas Instruments. This project is not affiliated with or endorsed by Texas Instruments.
• This is a hobby / interoperability project. Emulation of hardware for the purpose of running otherwise-licensed software is the user's responsibility. Emulation is not bound by the same rights as distrubuted documentation or an Actual Hardware Product

License

This emulator's source code is licensed under the MIT License

Note: this licence applies only to the original source code in this repository. It does not grant rights to any third-party documentation, ROM images, or firmware, which are not included here.