Moving An Embedded Project From x86 to PowerPC

An anonymous reader writes "This series on embedded development shows you how to migrate a project prototype from x86 to PowerPC. This initial installment explains the realities and rationale of the project: it introduces the robotic submarines that were the start of the project (and where they came from), and describes the Linux/GCC development environment and the bare-bones Kuro Box PowerPC development board."

Comments

You mean...

[2nd Post!]

Develop on PowerPC and then migrate to the x86?

But I quote from the article:

These processors are large and extremely energy-hungry; active cooling is almost universally required in x86 designs, and mains power is preferable. The dominant design factor steering x86-based designs is the baggage required by backwards compatibility (both in the CPU core and other support circuitry on the motherboard), and many people are doubtless aware of the history behind this. Vast effort has been invested to modernize the CPU and overall system architecture, but even the current 64-bit architectures are constrained to some degree by legacy considerations. There are relatively few true SoC offerings based around an x86-compatible core, and thus significant external circuitry is always required in x86 systems. It should also be noted that, unlike the vast majority of embedded devices, x86 chips lack on-chip JTAG or other hardware debugging interface support.

The problem is how to hook up mains, active cooling (liquid maybe?) and designing the external support circuitry for x86.

The PowerPC doesn't have that problem because:

one tends to find ARM in low-system-cost, high-volume applications, particularly where power consumption is the prime criterion; x86 is typically found in applications where PC-compatibility is the prime selection criterion, and PPC is often found in applications where performance is the prime criterion. The specific advantages I was hoping to realize in moving to PPC were reduced power consumption, elimination of active cooling (required in my Geode design because of the combined power dissipation of the CPU and its mandatory companion IC), and enhanced performance in some digital image processing (machine vision) code.

So the answer? PPC has lower thermal constraints, higher performance given fixed energy requirements, and lower part count.

Re:insane really use a Mips or ARM SOC

[2nd Post!]

Sure, but these guys went from x86->PPC successfully, so should and did are two different things.

I'm sure there are reasons for all these architectures. The PPC has the benefit of being reasonably scalable too: There are PPC cores from 200MHz up to 2.5GHz so you can develop on one and deploy on another.