Cross compile go apps on Windows 10

I wanted to try cross-compiling gotop for the Raspberry Pi 4 using my Windows 10 Laptop. It threw me an error (Yikes!):

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logging_other.go:11:2: undefined: syscall.Dup2

It was getting late, and I needed to get some grilling done. So I decided instead (for now) to go get it, build it, and install it on my Pi 4 and play with a simpler task: cross-compiling for the ARM processor.

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# go get gotop locally on my Pi 4

go get github.com/cjbassi/gotop

go build

go install

# See it running below

Here's gotop, showing load across 4 CPU Cores, memory, and process utilization. If you type the "?" operator it will show you the key bindings, and if you know vim, most of them will be familiar to you.

Now that I have gotop up and running (I hope to use it to see how loaded it gets using picamara in a VNC session), I'll show the important parts of cross-compiling from Windows 10 to the Pi 4.

You may also like: Cross-Compilation With Buildroot.

Here's a simple hello world that we'll cross-compile. I'll call the file howdy.go:

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package main

import "fmt"

func main() {

    fmt.Println("Howdy do")

}

The Pi 4 uses an ARM 7 processor, but you can check this by running the uname command.

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uname -a

Linux my-host 4.19.75-v7l+ #1270 SMP Tue Sep 24 18:51:41 BST 2019 armv7l GNU/Linux

Compile the sample howdy.go for Linux, specifying the ARM 7 processor:

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REM Compile for ARM 7 processor

c:> env GOOS=linux GOARCH=arm GOARM=7 go build

REM copy to Pi4

scp howdy pi@my-host:~/

Run it on your Pi 4, making sure the permissions are good to run it.

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chmod 755 howdy

./howdy

I hope you found this post both practical and interesting!

Further Reading

• An ARM Image With Buildroot.
• Be Aware: Floating Point Operations on ARM Cortex-M4F.
• Windows 10 Will Ship With a Full Linux Kernel.