[Arm-netbook] Somewhat off-topic updates about Ryzen, PolarFire, HiFive and Elbrus (was Re: Current status)

[Paul Boddie]

On Tuesday, 21 July 2020 23:36:28 CET Paul Boddie wrote:
> 
> So, upcoming AMD products could be decent, but I would be wary about
> stability for a while after their release. Following the Linux kernel bug
> tracker can be informative:
> 
> https://bugzilla.kernel.org/
> 
> Searching for "amdgpu" is probably what you want to do. For quite some time,
> people were having problems with the 3200G, and that made me worried about
> the 3400G, but it seems that even within product families there might be
> some parts that are better supported than others.

Since then, my Ryzen system has worked better than my work laptop that has an 
Intel Core 7 CPU with integrated graphics that aren't used because there is 
also an Nvidia video card which occasionally does some very weird display 
memory "picture interference" thing.

(I thought that might be the HDMI output playing up, having had to mess with 
Synopsys HDMI on the Ingenic JZ4780 and seeing the many weird things that have 
to be set up to enable the peripheral, but is probably some dodgy interaction 
between the binary firmware blobs and the baroque "Linux plus GNOME plus 
whatever is in-between" graphics stack.)

The only weird thing I have seen with the Ryzen 3400G is this kind of message 
(with dmesg prefixes removed):

Corrected error, no action required.
CPU:7 (17:18:1) MC3_STATUS[-|CE|MiscV|-|-|-|SyndV|-|-|-]: 0x9820000000000150
IPID: 0x000300b000000000, Syndrome: 0x000000002a000503
Decode Unit Ext. Error Code: 0, Micro-op cache tag parity error.
cache level: RESV, tx: INSN, mem-tx: IRD

I have no idea whether this is really bad or not.

[...]

> "A low-cost dev kit for Microchip's PolarFire SoC, a low-power FPGA
> integrated with a hardened quad core 64-bit RISC-V microprocessor
> subsystem"
> 
> https://www.crowdsupply.com/microchip/polarfire-soc-icicle-kit
> 
> That is from the Microsemi part of Microchip's business, however, meaning
> that it is another recent acquisition: Microchip presumably buying in new
> technology to remain competitive.

Since that campaign, they've started another:

"PolarBerry is a System-on-Module (SoM) SBC utilizing the Microchip PolarFire 
SoC, which integrates a low-power FPGA with a highly secure, four-application-
core, 64-bit, Linux-capable RISC-V subsystem."

https://www.crowdsupply.com/sundance-dsp/polarberry

They go on about how it has "defense-level security". And again, it relies on 
Microsemi's proprietary toolchain.

Meanwhile, this one slipped below the radar given that SiFive already 
crowdfunded a similar kind of board successfully a while back:

"Powered by the SiFive Freedom U740 RISC-V SoC and targeted for creating RISC-
V applications, the platform features 8 GB of 64-bit DDR4 memory operating at 
2400 MT/s, high-speed interconnects with PCIe Gen 3 x8 operating at 7.8 GB/s, 
Gigabit Ethernet, and USB 3.2 Gen 1."

https://www.crowdsupply.com/sifive/hifive-unmatched

However, I think this one might appeal to Luke a bit more:

"Elbrus is a mini-ITX security-oriented motherboard for mobile/embedded usage 
based on the MCST Elbrus-8CB 8-core @ 1.5 GHz VLIW CPU on ELBRUS 
architecture."

https://www.crowdsupply.com/sra-centr8/icepeakitx-elbrus-8cb

In case OpenPOWER isn't exciting enough.

Paul