mirror of
https://github.com/golang/go
synced 2024-11-05 11:36:10 -07:00
64 lines
2.9 KiB
Plaintext
64 lines
2.9 KiB
Plaintext
Native Client
|
|
=============
|
|
|
|
This document outlines the basics of building and developing the Go runtime and programs in the Native Client (NaCl) environment.
|
|
|
|
Go 1.3 supports two architectures
|
|
|
|
* nacl/386 which is standard 386.
|
|
* nacl/amd64p32 which is a 64 bit architecture, where the address space is limited to a 4gb window.
|
|
|
|
For background it is recommended that you read http://golang.org/s/go13nacl.
|
|
|
|
Prerequisites
|
|
-------------
|
|
|
|
Native Client programs are executed inside a sandbox, the NaCl runtime. This runtime must be installed before you can use NaCl programs.
|
|
|
|
The NaCl distribution comes with an installer which ensures you have access to the latest version of the runtime. The version tracks the Chrome numbering scheme.
|
|
|
|
# Download NaCl
|
|
|
|
Download nacl_sdk.zip file from https://developers.google.com/native-client/dev/sdk/download, and unpack it. I chose /opt/nacl_sdk
|
|
|
|
# Update
|
|
|
|
The zip file contains a small skeleton that can be used to download the correct sdk. These are released every 6-8 weeks, in line with Chrome releases.
|
|
|
|
% cd /opt/nacl_sdk
|
|
% ./naclsdk update
|
|
|
|
At this time pepper_33 is the stable version. If naclsdk downloads a later version, please adjust accordingly.
|
|
|
|
The cmd/go helper scripts expect that the runtime loaders, sel_ldr_x86_{32,64} are in your path. I find it easiest to make a symlink from the NaCl distribution to my $GOPATH/bin directory.
|
|
|
|
% ln -nfs /opt/nacl_sdk/pepper_33/tools/sel_ldr_x86_32 $GOPATH/bin/sel_ldr_x86_32
|
|
% ln -nfs /opt/nacl_sdk/pepper_33/tools/sel_ldr_x86_64 $GOPATH/bin/sel_ldr_x86_64
|
|
|
|
Support scripts
|
|
---------------
|
|
|
|
Symlink the two scripts in this directory into your $PATH, just as you did with NaCl sdk above.
|
|
|
|
% ln -nfs $GOROOT/go/misc/nacl/go_nacl_amd64p32_exec $GOPATH/bin/go_nacl_amd64p32_exec
|
|
% ln -nfs $GOROOT/go/misc/nacl/go_nacl_386_exec $GOPATH/bin/go_nacl_386_exec
|
|
|
|
Building and testing
|
|
--------------------
|
|
|
|
Building for NaCl is similar to cross compiling for other platforms. However, as it is not possible to ever build in a `native` NaCl environment, the cmd/go tool has been enhanced to allow the full build, all.bash, to be executed, rather than just the compile stage, make.bash.
|
|
|
|
The cmd/go tool knows that if GOOS is set to `nacl` it should not try to execute any binaries itself. Instead it passes their execution to a support script which sets up a Native Client environment and invokes the NaCl sandbox.
|
|
|
|
The script's name has a special format, go_$GOOS_$GOARCH_exec, so cmd/go can find it.
|
|
|
|
In short, if the support scripts are in place, the cmd/go tool can be used as per normal.
|
|
|
|
# Build and test Go for NaCl
|
|
|
|
NaCl does not permit direct file system access. Instead, package syscall provides a simulated file system served by in-memory data. The script nacltest.bash is the NaCl equivalent of all.bash. It builds NaCl with an in-memory file system containing files needed for tests, and then it runs the tests.
|
|
|
|
% cd go/src
|
|
% env GOARCH=amd64p32 ./nacltest.bash
|
|
|