| Sean Liao | 3c9c9e1 | 2022-01-22 17:27:16 +0100 | [diff] [blame] | 1 | **Note: NaCl support [was dropped in Go 1.14](https://go.dev/doc/go1.14#nacl).** |
| Filippo Valsorda | 19c265c | 2021-02-16 12:33:07 -0500 | [diff] [blame] | 2 | |
| Andrew Gerrand | 5bc444d | 2014-12-10 11:35:11 +1100 | [diff] [blame] | 3 | Go 1.3 includes support for generating x86-32 and x86-64 binaries for Google Native Client (NaCl). |
| 4 | |
| 5 | NaCl is a collection of related technologies. |
| 6 | |
| 7 | 1. NaCl defines a collection of binary formats with specific code layout requirements. There are definitions for 32- and 64-bit x86 and 32-bit ARM. |
| 8 | 1. NaCl provides a mechanism for running those binaries in a sandboxed execution environment with a restricted syscall-like interface. That syscall-like interface is not guaranteed to be stable from release to release. |
| 9 | 1. To abstract away the syscall-like interface, NaCl defines a stable runtime API called the integrated runtime (IRT). |
| 10 | 1. Using the IRT, Google Chrome defines an API called Pepper (aka PPAPI) that NaCl-based plugins use to interact with the browser. |
| 11 | 1. To abstract away the machine-specific binary formats, NaCl defines an LLVM-based architecture-independent format called PNaCl. |
| 12 | 1. NaCl provides translators from PNaCl format to the architecture-specific formats, invoked automatically, so that you can distribute just a PNaCl binary and execute on all three supported platforms. |
| 13 | |
| 14 | Go 1.3 provides support for generating the architecture-specific binaries and using the raw syscall interface (1 and 2 in the list above), and only for the x86 platforms (not for ARM). |
| 15 | |
| 16 | There is ongoing work exploring support for the IRT and PPAPI (3 and 4 in the list) but no definite release target. Perhaps they will be in Go 1.4 but perhaps not. |
| 17 | |
| 18 | There are no concrete plans to support PNaCl (5 and 6 in the list). |
| 19 | |
| Sean Liao | 3c9c9e1 | 2022-01-22 17:27:16 +0100 | [diff] [blame] | 20 | The Go 1.3-generated NaCl binaries can be run using the NaCl SDK sel\_ldr\_x86\_32 and sel\_ldr\_x86\_64 programs. They cannot be run directly in Google Chrome. As such, the NaCl support in Go 1.3 is useful only for running sandboxed environments like the [Go Playground](https://go.dev/play/). The file [misc/nacl/README](http://golang.org/misc/nacl/README) in the Go distribution explains how to configure your machine so that you can run and NaCl-sandboxed binaries using the go command. |
