Why X86 Needs To Die

As I’m sure many of you know, x86 architecture has been around for quite some time. It has its roots in Intel’s early 8086 processor, the first in the family. Indeed, even the original 8086 inherits a small amount of architectural structure from Intel’s 8-bit predecessors, dating all the way back to the 8008. But the 8086 evolved into the 186, 286, 386, 486, and then they got names: Pentium would have been the 586.

Along the way, new instructions were added, but the core of the x86 instruction set was retained. And a lot of effort was spent making the same instructions faster and faster. This has become so extreme that, even though the 8086 and modern Xeon processors can both run a common subset of code, the two CPUs architecturally look about as far apart as they possibly could.

So here we are today, with even the highest-end x86 CPUs still supporting the archaic 8086 real mode, where the CPU can address memory directly, without any redirection. Having this level of backwards compatibility can cause problems, especially with respect to multitasking and memory protection, but it was a feature of previous chips, so it’s a feature of current x86 designs. And there’s more!

I think it’s time to put a lot of the legacy of the 8086 to rest, and let the modern processors run free. Continue reading “Why X86 Needs To Die”

a CH32V003 Linux-bearing PCB, single-sided, hand-etched, lovely

Bring Linux To CH32V003 Through, Yes, RISC-V Emulation

Like playing around with Linux on low-power devices? You’d be hard pressed to find a better example than the [tvlad1234]’s linux-ch32v003 project. It’s not just a one-off — it’s something you could build right now, since it requires hardly any extra parts.

With help of a 8 MB PSRAM chip for RAM supplementation purposes and an SD card, plus some careful tailoring of the Linux .config parameters, you get Linux on a chip never meant to even come close to handling this much power. The five minutes it takes to boot up to a prompt is part of the experience.

As usual with [tvlad1234]’s projects, there’s a fun twist to it! Running Linux on this chip is only possible thanks to [chlohr]’s mini-rv32ima project, which, as you might remember, is a RISC-V emulator. Yes, this runs Linux by running a RISC-V emulator on a RISC-V chip. The main reason for that is because the MCU can’t map the PSRAM chip into RAM, but if you use an emulator, memory mapping is only a matter of software. Having applied a fair amount of elbow grease, [tvlad1234] brings us buildroot and mainline Linux kernel configs you can compile to play with this — as well as a single-layer-ready KiCad board project on GitHub. Yep, you could literally etch a PCB for this project from single-sided copper-clad FR4 with a bit of FeCl3.

While the CH32V003 is undoubtedly a more impressive target for Linux, the RP2040 Linux project might be more approachable in terms of having most of the parts in your parts box. At least, up until we start valuing the CH32V003 for all the cool stuff it can do!

Compute The Mandelbrot Set With A Custom RISC-V CPU

When faced with an FPGA, some people might use it to visualize the Mandelbrot set. Others might use it to make CPUs. But what happens if you combine the two? [Michael Kohn] shows us what happens with his RISC-V CPU with an instruction specially made for computing the Mandelbrot set.

[Michael] takes us through the unusual process of turning his 8008 into a RISC-V CPU. Re-using bits of logic here and replacing other logic there leaves him with a functional RISC-V core. Not finished, [Michael] takes it upon himself to also create a custom instruction just for computing a point for the Mandelbrot set, accelerating the demo from twenty-three seconds to merely one!

Still not finished, [Michael] also creates an implementation of the long gone F100-L CPU, once again with added Mandelbrot set flair, simultaneously with the RISC-V project. Finally, he ports his “Java Grinder” Java bytecode compiler to both RISC-V and the F100-L, because Java runs on 1 Billion devicesTM.

Continue reading “Compute The Mandelbrot Set With A Custom RISC-V CPU”

CH32 RISC-V MCUs Get Official Arduino Support

Like many of you, we’ve been keeping a close eye on the CH32 family of RISC-V microcontrollers from WCH Electronics. You can get the CH32V003, featuring 2 kB RAM and 16 kB of flash for under fifteen cents, and the higher-end models include impressive features like onboard Ethernet. But while the hardware is definitely interesting, the software side of things has been a little rocky compared to what we’ve come to expect from modern MCUs.

Things should start looking up a bit though with the release of an Arduino core for the CH32 direct from WCH themselves. It’s been tested on Windows, Linux, and Mac, and supports the CH32V00x, CH32V10x, CH32V20x, CH32V30x, and CH32X035 chips. Getting it installed is as easy as adding the URL to the Arduino IDE’s Boards Manager interface, though as the video below shows, running it on Linux does require an extra step or two.

So far, we’ve seen several projects, like this temperature sensor or this holiday gizmo that use [cnlohr]’s open-source toolchain. But there’s no question that plenty of hobbyists out there feel more comfortable in the Arduino environment, and if those folks are now able to pick up a CH32 and do something cool, that means more people jumping on board, more libraries developed, more demo code written…you get the idea.

Just like the ESP8266’s popularity exploded when it was added to the Arduino IDE, we’ve got high hopes for the CH32 family in the coming months.

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How IBM Stumbled Onto RISC

There are a ton of inventions out in the world that are almost complete accidents, but are still ubiquitous in our day-to-day lives. Things like bubble wrap which was originally intended to be wallpaper, or even superglue, a plastic compound whose sticky properties were only discovered later on. IBM found themselves in a similar predicament in the 1970s after working on a type of mainframe computer made to be a phone switch. Eventually the phone switch was abandoned in favor of a general-purpose processor but not before they stumbled onto the RISC processor which eventually became the IBM 801.

As [Paul] explains, the major design philosophy at the time was to use a large amount of instructions to do specific tasks within the processor. When designing the special-purpose phone switch processor, IBM removed many of these instructions and then, after the project was cancelled, performed some testing on the incomplete platform to see how it performed as a general-purpose computer. They found that by eliminating all but a few instructions and running those without a microcode layer, the processor performance gains were much more than they would have expected at up to three times as fast for comparable hardware.

These first forays into the world of simplified processor architecture both paved the way for the RISC platforms we know today such as ARM and RISC-V, but also helped CISC platforms make tremendous performance gains as well. In fact, RISC-V is a direct descendant from these early RISC processors, with three intermediate designs between then and now. If you want to play with RISC-V yourself, our own [Jonathan Bennett] took a look at a recent RISC-V SBC and its software this past March.

Thanks to [Stephen] for the tip!

Photo via Wikimedia Commons

A RISC-V Security Key

The TKey is a RISC-V-based security key that plugs into a USB port. The device has a number of features, including a device-specific serial number, RAM scrambling, and a monitor that kills the CPU in the event of access to protected memory. There is also an FPGA that, on the end-user version, is locked down. This prevents you from changing the core features and the unique ID number for the device.

As part of the start-up code, the device calculates a hash of the application and merges it with the device ID and, potentially, a user-defined secret. If this number matches a previous calculation, it is reasonably certain that nothing has changed between the times of the calculations.

Continue reading “A RISC-V Security Key”

Increase Your Blinkenlights With This Silicon Wafer Necklace

Necklaces aren’t often very high-tech, mostly because of the abuse they have to go through being worn. This was obviously a problem that needed solving, so [Matt Venn] decided to change that by making a necklace out of ASICs just in time for Supercon.

Although this isn’t the first time [Matt] made such a necklace, he though his previous one was “too hip-hop” and not enough “15 million dollar Nikon Lithography Stepper”. Obviously, this means designing the whole chain, art included, from scratch with the blinkenlights to match. Together with [Pat Deegan] and [Adam Zeloof], the team created a beautiful technopunk necklace with art on every chain link and of course a real silicon wafer with a RISC-V tapeout from 2022 on it.

With [Adam] doing modeling for the chain links, and [Pat] and [Matt] designing the electronics required for the mandatory blinkenlights, and some last-minute soldering and assembling the project was finished just in time for Supercon, where it fit right in with all the other blinkenlights. It even runs on one of the RISC-V cores from the same tapeout as the central wafer!