piCorePlayer6.1.0-Xenomai-44.1-48KHz雙機入門簡易安裝教學

[seeteeyou]

感謝 tetsuka 兄的回覆，看來日本網友的文采真不錯。

另外小弟給 Higuma 兄的回覆已搬到另一邊了，謝謝：

https://www.my-hiend.com/vbb/showthr...373#post243373

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Qualcomm Acquires NUVIA For $1.4 Billion To Take Apple, Intel And AMD Head-On
https://www.forbes.com/sites/davealt...nd-amd-head-on

Upcoming ARM Chip That's Faster Than Apple Silicon M1
https://singhkays.com/blog/arm-cpu-f...than-apple-m1/

How We Ported Linux to the M1
https://corellium.com/blog/linux-m1


單核速度超快的 Apple M1 也可以跑 Ubuntu 了，但是跑 ARM64 版的 piCorePlayer 該是比較困難吧？

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另外把 RPi4 的 BCM2711 超頻到 2.205GHz 的時候好像是聲音會更好，如果這電競手機的 Snapdragon 865 Plus 能夠跑 Linux 的話也許會很棒？

Snapdragon 865 Plus Can Reach 3.40GHz on Its Prime Core, up From 3.10GHz While Running Very Cool in the ROG Phone 3
https://wccftech.com/snapdragon-865-...n-rog-phone-3/

How to Root Asus ROG Phone 3 in 5 Minutes
https://magiskupdate.com/root-asus-rog-phone-3/

How to Root Asus ROG Phone 3 with Magisk (Updated Guide)
https://magiskapp.com/root-asus-rog-...3-with-magisk/

這個 RB5 開發板的 QRB5165（工業版 Snapdragon 865）主核速度只是比 Plus 版本慢一點，而且 RB5 跑 Kernel 5.10 的 Ubuntu 也沒有問題：

https://www.thundercomm.com/app_en/p...90131656070623
https://releases.linaro.org/96boards...mbedded/20.12/
https://releases.linaro.org/96boards...8133815-v2.zip

Kernel 5.10：

https://git.yoctoproject.org/cgit/cgit.cgi/meta-qcom
https://github.com/ndechesne/meta-qcom
https://github.com/96boards/meta-rpb

Xenomai 這邊的 Kernel 5.4 Device Tree Source 找不到 SD865 的 part number SM8250：

https://gitlab.denx.de/Xenomai/ipipe.../boot/dts/qcom

大概是把比較新的 SM8250 搬到 Kernel 5.10 的 EVL 了：

https://git.evlproject.org/linux-evl...m?h=evl/master
https://www.symphonic-mpd.com/forum/post/1042

RPi4版は、Xenomaiの後継ソフトであるEVLを採用することにしました。

https://evlproject.org/

Xenomaiのメンテナの1人であるPhilippe Gerumさんが開発を進めているソフトです。
PhilippeさんはXenomaiのarm/arm64向けパッチの大半をコミットしてきた方で、メーリングリストで"今後はEVLに注力する"と発言されてらっしゃいました。

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XenomaiカーネルではPi4でUSB利用時にハングアップする現象を回避することができませんでしたが、EVLではカーネルにパッチを当てることでUSBも動作するようになりました。（あくまで応急処置に過ぎず、安定動作とまではいきませんが、、、外付けSSDが実用レベルになりましたので開発が捗ります）

年末年始に、aplay-rt/rtalsa/xsinkをEVLに移植する作業に取り掛かりたいと思います。

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RPi4版のスペックは

• Linuxカーネル 5.x系を採用
• リアルタイムカーネルにEVLを採用
• カーネル/アプリケーションは全て64bitでビルド
• RPi4専用のビルドオプションを使用
• コンパイラにgcc9.2 (またはgcc10)を採用
• EVL向けにデバイスドライバを新規開発

となりそうです。

https://gitlab.denx.de/Xenomai/xenomai/-/wikis/home

We are also paving the way to Xenomai 4, which is going to be based on the next generation real-time core developed by the EVL project, with the intent to preserve the user investment in Xenomai 3.x. To this end, the specification process of a Common Xenomai Platform has started. By this process, we define a set of common features and interfaces future Xenomai releases will share, starting from Xenomai 3.3.

https://xenomai.org/pipermail/xenoma...er/043931.html

Xenomai 3.x and earlier have long promoted the RTDM interface for implementing drivers, which encourages a separated driver model by design. Instead, the EVL core which is going to be the cornerstone of Xenomai 4 promotes an integrated approach to developing real-time drivers when possible, by adding so-called "out of band" capabilities directly to the implementation of existing mainline drivers [1][2]. A custom EVL driver which has no counterpart in the mainline kernel tree is still a regular character device driver, although it must use the real-time services brought by the EVL core for its time-critical operations [3].

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或許寬溫的工業版比較佔優？

https://www.androidauthority.com/qua...world-1129615/

The Robotics RB5 uses the QRB5165 processor with the same CPU, GPU, ISP, and DSP as the Snapdragon 865, but this time with support for industrial-grade temperate ranges from -40°C to 105°C, plus some nice enhancements around computer vision.

畢竟 JPLAY 的作者 Marcin 兄也是選擇寬溫的工業版 CF／RAM／SSD，聲音會比較好？

http://jplay.eu/forum/index.php?/top...-81#entry41546

- 2x4GB Apacer ECC DDR4 UDIMM RAM - industrial grade, extended temp. range (-40 - +85)
- OCXO CF-SATA adapter /w 32GB Apacer SLC CF card for OS - industrial grade, extended temp. range (-40 - +85)

http://jplay.eu/forum/index.php?/top...to/#entry52374

2x 4GB ECC RAM Apacer DDR4 ECC UDIMM (industrial extended temp. range RAM)
Apacer SLC SSD for OS (industrial extended temp. range) 64GB
APRO pSLC SSD for music (industrial extended temp. range)

http://jplay.eu/forum/index.php?/top...e-2#entry49239

Just arrived and installed in my PC: https://industrial.apacer.com/en-ww/...emp.-ECC-UDIMM

It replaces the previous generation of Apacer (75.B93H0.G000B). Amazing improvement over the predecessor

另一高手 Nenon 兄：

https://audiophilestyle.com/forums/t...omment-1005952

My guess is that the component quality matters as well as the execution, quality of service, etc. Apacer is doing a good job with their industrial wide range temperature RAM, and it is a no brainer to me.

RPi4 的 RAM 則全屬 Wireless Temperature：

https://www.raspberrypi.org/forums/v...c.php?t=277251

2GiB date: 9LD77 part#: D9WHZ
4GiB date: 9FD77 part#: D9WHV
8GiB date: OAA47 part#: D9ZCL

https://www.micron.com/support/tools...=D9WHZ#pnlFBGA

MT53D512M32D2DS-053 WT:D

https://www.micron.com/support/tools...=D9WHV#pnlFBGA

MT53D1024M32D4DT-053 WT:D

https://www.micron.com/support/tools...=D9ZCL#pnlFBGA

MT53E2G32D4NQ-046 WT:A

https://www.micron.com/-/media/clien...de/numdram.pdf

WT = Wireless temperature
XT = Wide temperature

https://media.digikey.com/PDF/Data%2...5W8MW16BGX.pdf

– Wireless (–30°C to +85°C) WT
– Industrial (–40°C to +85°C) IT