在 x86-64 上跑 Raspberry Pi 的 OS

看到「dockerpi」這個專案,讓你可以在 x86-64 上模擬 Raspberry Pi 環境跑 Raspbian

然後整包是先透過 Docker 產出一個獨立環境,然後裡面跑 QEMU 模擬 ARM 的環境,接下來再跑 Raspbian:

A full ARM environment is created by using Docker to bootstrap a QEMU virtual machine. The Docker QEMU process virtualises a machine with a single core ARM11 CPU and 256MB RAM, just like the Raspberry Pi. The official Raspbian image is mounted and booted along with a modified QEMU compatible kernel.

這馬上讓人想到 Inception 啊 XDDD


Raspberry Pi 4 的 Type C 無法使用 Macbook Charger 供電的問題

Raspberry Pi 4 出來後有些災情 (畢竟又加了不少東西近去),在 Hacker News 上看到的 Type C 介面的充電問題:「Raspberry Pi 4 not working with some chargers (scorpia.co.uk)」,引用的原文可以在「Pi4 not working with some chargers (or why you need two cc resistors)」這邊看到,裡面提到了新的 Type C 供電介面在接某些充電器時不會供電 (包括了 Macbook 的充電器):

The new pi has been released and it has a USB Type-C connector for power however people are finding some chargers are not working with it (notably macbook chargers). Some have speculated that this is due to a manufacturer limitation on the power supplies however it is actually due to the incorrect detection circuitry on the Pi end of the USB connection.

這樣說有點偏頗,但是 Macbook 的充電器一向是 Type C 裡的指標,如果這顆充電器跟其他裝置配合上有問題,通常都是代表其他裝置的實作有問題... (噗)

這次發現的電阻問題看起來有點苦 (看起來需要改版子),目前文章作者建議的 workaround 主要就是「不要用那麼好的設備」,比較簡單的包括了 Type C 的線不要那麼好 (像是找充手機用的線就好,不要找拿可以跑 5A 的線),或是透過 Type A 轉 Type C 的線也應該可以避開這個問題,最差的情況應該是找其他的充電器:

Now onto some solutions. Assuming the issue you are having is caused by the problem discussed above, using a non e-marked cable (most USB-C phone charger cables are likely this type) rather than an e-marked cable (many laptop charger/thunderbolt cables and any 5A capable cable will be in this category) will allow for the pi to be powered. In addition using older chargers with A-C cables or micro B to C adaptors will also work if they provide enough power as these don’t require CC detection to provide power. Ultimately though the best solution in the long run will be for there to be a board revision for the pi 4 which adds the 2nd CC resistor and fixes the problem.

對於已經入手的人,如果真的中獎,workaround cost 應該還在可以控制的範圍...

Raspberry Pi 4 開賣,USD$35

Raspberry Pi 4 開賣,目前推出的是 Model B,最低規格的 1GB RAM 版本與之前 RPi 3 相同都是 USD$35,另外這次提供了以前沒有的 2GB 與 4GB 版本,分別是 USD$45 與 USD$55:「Raspberry Pi 4 on sale now from $35」。

有兩個比較大而且要注意的改變,第一個是電源接頭變成 Type-C 了:

We’ve moved from USB micro-B to USB-C for our power connector. This supports an extra 500mA of current, ensuring we have a full 1.2A for downstream USB devices, even under heavy CPU load.

另外一個是 HDMI 接頭換成 D Type:

To accommodate dual display output within the existing board footprint, we’ve replaced the type-A (full-size) HDMI connector with a pair of type-D (micro) HDMI connectors.


這次改版最明顯的是效能的增加,官方宣稱 CPU 速度是前一代的三倍:

A 1.5GHz quad-core 64-bit ARM Cortex-A72 CPU (~3× performance)

而在 GPU 相關的則是對 H.265 的 4Kp60 硬體解壓縮:

4Kp60 hardware decode of HEVC video

先前用 RPi 3 放客廳還是覺得不太夠,也許可以考慮看看這個...

在 Raspberry Pi 上面設定 Fixed IP (Static IP)

家裡本來是用 Raspberry Pi (第一代) 跑 SmokePing 觀察有線電視提供的網路 (看品質狀況),但前陣子 SD card 掛掉了... 只好網路上找一張新的 SD card 重新裝一套系統。

在拿到卡後去 Raspberry Pi 的官網上下載最新版的 Raspbian,發現版本變新後,裡面有不少東西不一樣了 :o

固定 IP address 以前都是改 /etc/network/interfaces,但裡面可以看到還蠻有趣的警告,我就是要設定 Static IP:

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

這邊說明了如果要設定固定 IP 的話不要改這個檔案,而是修改 /etc/dhcpcd.confdhcpcd 處理。


interface eth0
static ip_address=
static routers=
static domain_name_servers=


擋廣告的 Pi-hole

Pi-hole 最近愈來愈紅的一個計畫,技術上是透過 DNS 把不想要的網域名稱擋掉,通常就是擋掉各種 tracking 與廣告系統。

因為是透過 DNS 擋,當然沒有像 uBlock Origin 直接 parse 網頁內容來的有效,但對於方便性來說則是大勝,只需要在網路設備上設一次,所有的裝置都可以用到。

剛剛看到「How a Single Raspberry Pi made my Home Network Faster」這篇,可以看到 Pi-hole 有不錯的介面可以看 (讓你自我感覺良好?XD):


Review after 1 month in operation
The Pi-Hole has been running for 1 month now on my home network. I have had to whitelist 1 or 2 URLs which was blocking a reset of an Alexa which had an issue, and a video conferencing system had all sorts of tracking and metrics built in which were causing some havoc until I whitelisted them. Otherwise, the Pi has been chugging along at 8% memory utilization, and the network is considerably faster when surfing the web.

對於手癢自己玩應該還可以,拿到辦公室的話應該會有不少東西掛掉... (不過文章作者好像想這樣做)


看到「The curious case of the Raspberry Pi in the network closet」這篇有趣的過程,先從開頭與最後面開始看。首先是他們在辦公室裡面發現有個奇怪的設備:


I checked the DNS logs and found the exact date and time when the Pi was first seen in the network. I checked the RADIUS logs to see which employee was at the premises at that time and I saw multiple error messages that a deactivated account tried to connect to wifi.

That deactivated account belongs to an ex employee who (for some reason) made a deal with management that he could still have a key for a few months until he moved all his stuff out of the building (don't ask..).

中間的過程還蠻有趣的,包括研究是什麼擴充卡 (以及用途),然後從 SD card 上面挖資料,配合 Google 找線索,還有透過 WiGLE 定位,以及透過內部系統交叉比對,最後找到兇手...

然後發現是離職員工以搬東西當作理由,讓他在離職後還有辦公室鑰匙而導致的 XDDD

24 Core 的 ARM Server...

在「Banana Pi to Launch a 24-Core Arm Server」這邊看到 Banana Pi 打算推出 24 core 的 ARM server...


We have 24-core Arm Cortex A53 processor with 32GB RAM (29.4GB seen by the OS) running Ubuntu 18.04.1 LTS with MATE desktop. There aren’t that many 24-core Arm Cortex A53 processors, so unless the company is using an announced processor, it has to be SocioNext SC2A11 processor also found in Linaro Developer Box.

拿來當 desktop 好像也不錯,不知道最終的定價會是多少...

幫 Raspberry Pi 加風扇...

先前 Raspberry Pi 上只有貼小顆散熱片,當時測試如果是不裝殼的話效果還不錯,但為了保護的原因,決定在透明壓克力殼上打兩個洞後裝上去,結果效果沒有很好...

昨天去光華弄了兩顆吃 GPIO 電的 Raspberry Pi 小風扇 (5V 0.2A),把一顆丟進殼裡,也沒固定 (放在散熱片的位置上),就算有透明殼的阻擋,效果也很明顯,看起來熱都透過之前的兩個洞散出來了:

效果比室內開冷氣時還好,這樣可以比較安心的加壓 + overclock 了。


Raspberry Pi 3 的新版本 Model B+

Raspberry Pi 3 推出了 Model B+ 的新版本:「Raspberry Pi 3 Model B+ on sale now at $35」。

除了 CPU 速度稍微快一些以外,另外支援了 802.11ac/5Ghz 的無線網路 (官方宣稱可以跑到 ~102Mbps,相較於先前在 2.4Ghz 只能跑到 ~35Mbps),以及更快的有線網路 (官方宣稱可以跑到 ~315Mbps,相較於先前的 ~95Mbps)。

然後是支援 PXE

Raspberry Pi 3B was our first product to support PXE Ethernet boot. Testing it in the wild shook out a number of compatibility issues with particular switches and traffic environments. Gordon has rolled up fixes for all known issues into the BCM2837B0 boot ROM, and PXE boot is now enabled by default.

以及支援 PoE 直接推動整台機器:

We use a magjack that supports Power over Ethernet (PoE), and bring the relevant signals to a new 4-pin header. We will shortly launch a PoE HAT which can generate the 5V necessary to power the Raspberry Pi from the 48V PoE supply.

或是吃更多電 XDDD

Note that Raspberry Pi 3B+ does consume substantially more power than its predecessor. We strongly encourage you to use a high-quality 2.5A power supply, such as the official Raspberry Pi Universal Power Supply.

所以看到這張圖時就不意外了 XDDD (風扇!)


Update:風扇那張圖的產品頁看起來在「Raspberry Pi PoE HAT」這頁 (參考下面的 comment)。

微軟的 Time Service 回應錯誤的時間...

看起來會有不少災情 (像是 SQL Server 遇到使用 server side 的時間的 SQL query):「Windows Time Service is sending out wrong times and that’s a big problem」,報導裡引用了 Reddit 上「PSA: time.windows.com NTP server seems to be sending out wrong time」這邊的討論串。

為了避免這種情況,不同單位會用不同方法解決。像是財力充足的 Google 就自己搞了原子鐘,然後還放 Google Public NTP 出來給大家用。可以不倚靠外部裝置確保自家時間的正確性。

另外是有人用 Raspberry Pi 收 GPS 訊號轉成 NTP service (像是「The Raspberry Pi as a Stratum-1 NTP Server」這邊介紹的方式),不過之前有發生過 GPS 送出來的時間差了 13ms 的事情,也不是完全可靠 (不過相較起來應該還是可以接受):「GPS error caused '12 hours of problems' for companies」。另外可能的方案有 GLONASS (俄羅斯的系統)。