Compile 32 bit binary on 64 bit system

I've coded a Go program in a 64 bit system but I want to compile a 32 bit binary!

The 64 bit binary is working just great but I have no idea how to create a 32 bit binary.

How can I do it?

If you built your Go from source, then you can build any additional compilers and libraries for any CPU and OS. If you are on windows/amd64 and want to build for windows/386, then this will build everything you need to compile for windows/386:

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set GOARCH=386  
cd %GOROOT%\src  
make.bat --no-clean  

Once you have done that, you can build your windows/386 executable with:

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set GOARCH=386  
cd %YOUR_PROG_DIR%  
go build  

Since you are on windows/amd64, you should be able to even run / test your windows/386 programs too. Just make sure to set GOARCH=386 before you invoke any commands for windows/386.

One caveat: this does not support cgo, so you cannot use any packages that use cgo.

The way I have achieved this (without any compiling of the compiler) on my Windows 7 64 bit PC was first having the windows amd64 installed, then download 32bit zip and unpack to a second folder:

\go\go32
\go\go64

By then adjusting the PATH and the GOROOT inside my command prompt window as follows:

set PATH=\go\go32;%PATH%
set GOROOT=\go\go32\

Then I went back and recompiled my app that was previously compiling using the 64 bit. All this can be setup in a batch if you want to switch between regularly.

Ok, I've finally solved the problem! Here it is how I did it(I was miserably failing actually!).

• The first thing I did was to download GCC from http://www.mingw.org/.

• Next I added C:\MinGW\bin to the PATH environment variable(I'm assuming that MinGW is installed in C:\MinGw)

• Next thing before running go build/go install is to set the enviroment variables.

• Open the command prompt and cd to C:\Go\src and run all.bat from the command line.

• Set GOOS, GOARCH and CGO_ENABLED to windows, 386 and 0 respectively! (you should also set GOPATH to the path where your current Go project is).

• Next run make.bat and make.bat --no-clean
  After that you can build your project for 32 bit systems! I hope this is helpful!

My Go version is 1.14 ,I change make.bat as follow:

:: if "x%GOROOT_BOOTSTRAP%"=="x" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\Go1.4

Change GOROOT_BOOTSTRAP to my Go's root:

if "x%GOROOT_BOOTSTRAP%"=="x" set  GOROOT_BOOTSTRAP=D:\Go

after that I got this error

go tool dist: unknown $goarch 386

then I set GOOS and GOARCH

setlocal
set GOROOT=%GOROOT_BOOTSTRAP%
set GOOS=
set GOARCH=
set GOBIN=
set GO111MODULE=off
"%GOROOT_BOOTSTRAP%\bin\go.exe" build -o cmd\dist\dist.exe .\cmd\dist
endlocal

set GOOS AND GOARCH as follow

setlocal
set GOROOT=%GOROOT_BOOTSTRAP%
set GOOS=windows
set GOARCH=386
set GOBIN=
set GO111MODULE=off
"%GOROOT_BOOTSTRAP%\bin\go.exe" build -o cmd\dist\dist.exe .\cmd\dist
endlocal

But I got error this is not a 32bit program.