GoArm.md

# Introduction

Go is fully supported on Linux and Darwin. Any Go program that you can compile for x86/x86\_64 should work on Arm. Besides Linux and Darwin, Go is also experimentally supported on FreeBSD, and NetBSD.

# Supported architectures

Go supports the following ARM architectural families.

| **Architecture** | **Status** | **GOARM value** |
|:-----------------|:-----------|:----------------|
| ARMv4 and below  | sorry, not supported | n/a   |
| ARMv5            | supported  | GOARM=5         |
| ARMv6            | supported  | GOARM=6         |
| ARMv7            | supported  | GOARM=7         |
| ARMv8            | supported  | GOARCH=arm64    |

Starting from Go 1.1, the appropriate GOARM value will be chosen if you compile the program from source on the target machine. In cross compilation situations, it is recommended that you always set an appropriate GOARM value.

# Supported operating systems

* ARM on Linux. You must run an [EABI](http://wiki.debian.org/ArmEabiPort) kernel. These are generally known as `armel` for softfloat (compatible with ARMv5) or `armhf` for hardware floating point (ARMv6 and above).
* ARM on Darwin.
* ARM on FreeBSD and OpenBSD.

# Recommended Go version

The recommended minimum version for running Go on arm systems is Go 1.1.

# Tips and tricks

## /tmp and tmpfs
The ` go ` build tool uses ` /tmp ` when compiling and testing, this can cause heavy wear and tear if ` /tmp ` lives on your SD card. To minimise this effect, either ` export TMPDIR ` to somewhere that lives on another filesystem. Alternatively if you have lots of physical memory you can mount a swap backed tmpfs filesystem on /tmp by adding this line to ` /etc/fstab `

```
tmpfs /tmp tmpfs nodev,nosuid,mode=1777 0 0
```

## Swap
Building Go from source requires at least 256mb of RAM. Running the tests requires at least 256mb of memory and at least 512mb of swap space.

## Build failures due to lack of memory
The Go tool will try to keep all your cpu cores busy when installing packages (during make.bash),
this is normally preferable on PCs where memory is abundant.
However, some powerful multicore ARM machines don't have enough memory to support parallel
builds utilizing all available cores, and you can work around that by using the ` taskset(1) ` utility
to limit Go to only use one core without resorting to swaps.
```
taskset 1 ./make.bash # use 3 if you want to use two cores
```
Note: the 1 here is a bitmask for cpu affinity and it's not the number of cpu cores you're
willing to use, please refer to ` taskset(1) ` manual for details.

# Known issues

## Lack of floating point hardware on ARMv5
The major issue with ARMv5 is the lack of floating point support in common ARMv5 harware<sup>†</sup>. When compiled with the GOARM=5 environment variable, the 5l linker will insert a call to ` _sfloat ` before any block of floating point instructions to branch into the floating point emulator. This means that binaries produced with a Go installation that was compiled with soft float support will work on all supported architectures, but builds compiled without soft floating point support will not work on ARMv5.

<sup>†</sup> This isn't strictly true, there exist ARMv5 implementations which have VFP1 floating point. However the compiler doesn't support VFP1 yet.

## html/template and test/nilptr.go test fail on HTC Android
html/template test and test/nilptr.go is known to fail on HTC's Android kernels ([ref](http://www.mail-archive.com/android-developers@googlegroups.com/msg153389.html)), because the kernel will kill  the application after 10 segfaults.

## Potential kernel bug in 2.6.32-5-kirkwood on QNAP 219P
See [Issue 5466](https://github.com/golang/go/issues/5466) for details. Updating to 3.2.0-4-kirkwood solved the issue.

# Success stories

ARM hardware comes in a myriad of shapes and sizes. If you've had a success story building and running Go on your Arm system, please detail your results here.

## Netgear Stora

Architecture: ARMv5

Operating System: Debian Sid

The Netgear Stora is an ARMv5 (Marvell Kirkwood) platform. I flashed mine with a Debian Sid distribution and it was, until Go1, a solid platform for Go development. The main drawback is the Stora only has 128mb of ram, which is not quite enough to run ./all.bash as 5l can use more than 100mb of ram when linking some commands.

Instructions for installing Debian on your Stora can be found on the OpenStora website, http://www.openstora.com/wiki/index.php?title=How_to_install_Debian_Linux_on_NETGEAR_Stora.

> _-- dave cheney_

## Qnap TS-119P II

Architecture: ARMv5

Operating System: Debian Squeeze

The Qnap TS series of NASs are excellent hackable little linux hosts. The TS-11P9 II is a 2Ghz Marvell Kirkwood ARMv5 processor with 512mb of ram and a single SATA drive bay.

The kirkwood platform is supported by the native debian installer. http://www.cyrius.com/debian/kirkwood/qnap/ts-119/install.html

> _-- dave cheney_

## Pandaboard

Architecture: ARMv7

Operating System: Ubuntu 12.04LTS (armhf)

The Pandaboard is a dual core ARMv7 development board based on the Texas Instruments OMAP4 SoC platform. I run ubuntu 12.04 LTS server on mine, which is an excellent distribution for Arm development. The Pandaboard has a gig of ram which makes it excellent for development and benchmarking.

Instructions and SD card image can be found on on the Ubuntu wiki, https://wiki.ubuntu.com/ARM/Server/Install#Installing_pre-installed_OMAP4_Precise_.2812.04.29_Server_Images.

> _-- dave cheney_

## BeagleBone

Architecture: ARMv7 single core, Cortex-A8, 256MB RAM, 720 MHz

Operating System: Angstrom Linux

BeagleBone is similar to Beagleboard, but without the video components. Angstrom is a very small Linux distribution for ARM based systems. It is built on top of Yocto and OpenEmbedded with additional tools and recipes to make it even easier to build a distribution. You can think of Angstrom as Ubuntu and OpenEmbedded/Yocto as Debian. Angstrom is very light weight and fast compared to Ubuntu. It uses systemd instead of the sys5 scripts which help give you a very fast boot time of a few seconds.

BeagleBone is probably faster than a RasberryPI because of it's newer Cortex-A8 dual-issue superscalar architecture, but the PI has the GPU which theoretically could be used with something like OpenCL to really run circles around the BeagleBone. However, for embedded applications the BeagleBone is easier to work with because it is ready out of the box with GPIO connections.

I've cross compiled for ARM with 5g from a Mac and so far I haven't run into any problems. You can build on the BeagleBone, but cross compiling with Go is so easy that it is better to save wear and tear on the flash drive and just compile somewhere else.

> _-- hans stimer_

### Zyxel NSA 310

Architecture: ARM5
Platform: Debian Wheeze

Successfuly built default branch, going to write fan control daemon for this device in golang.

### Raspberry Pi

* [Building Go 1.5 on the Raspberry Pi - Dave Cheney](http://dave.cheney.net/2015/09/04/building-go-1-5-on-the-raspberry-pi)

Architecture: ARM1176JZFS, with floating point, running at 700Mhz

Operating System: Debian Wheezy beta distribution (http://www.raspberrypi.org/archives/1435) reported as:

` Linux raspberrypi 3.1.9+ #125 PREEMPT Sun Jun 17 16:09:36 BST 2012 armv6l GNU/Linux `

**Memory Split**: the Pi shares its 256mb of memory between the CPU and the GPU. You should allocate as much memory as possible to the CPU for a successful compilation. The configuration for the memory split is stored on your SD card. This link has a script to adjust the configuration, http://sirlagz.net/?p=445.

Go version weekly.2012-03-27 +645947213cac, with timeout and GOARM 7 patches http://codereview.appspot.com/5987063/) builds with 2 test failures: encoding/gob fails with out of memory, and fmt fails the NaN test.

Successfully installed and run SVGo via go get github.com/ajstarks/svgo, tested with goplay:

![http://farm8.staticflickr.com/7139/7451061716_fbb585c55f.jpg](http://farm8.staticflickr.com/7139/7451061716_fbb585c55f.jpg)

Division benchmark via http://codereview.appspot.com/6258067:


```
$ cd $GOROOT/src/pkg/runtime
$ go test -test.bench=BenchmarkUint


BenchmarkUint32Div7	 5000000	       547 ns/op
BenchmarkUint32Div37	 5000000	       547 ns/op
BenchmarkUint32Div123	 5000000	       547 ns/op
BenchmarkUint32Div763	 5000000	       547 ns/op
BenchmarkUint32Div1247	 5000000	       547 ns/op
BenchmarkUint32Div9305	 5000000	       547 ns/op
BenchmarkUint32Div13307	 5000000	       547 ns/op
BenchmarkUint32Div52513	 5000000	       547 ns/op
BenchmarkUint32Div60978747	 5000000	       547 ns/op
BenchmarkUint32Div106956295	 5000000	       547 ns/op
BenchmarkUint32Mod7	 5000000	       547 ns/op
BenchmarkUint32Mod37	 5000000	       547 ns/op
BenchmarkUint32Mod123	 5000000	       547 ns/op
BenchmarkUint32Mod763	 5000000	       547 ns/op
BenchmarkUint32Mod1247	 5000000	       547 ns/op
BenchmarkUint32Mod9305	 5000000	       547 ns/op
BenchmarkUint32Mod13307	 5000000	       547 ns/op
BenchmarkUint32Mod52513	 5000000	       547 ns/op
BenchmarkUint32Mod60978747	 5000000	       547 ns/op
BenchmarkUint32Mod106956295	 5000000	       547 ns/op
```

Running the hardware floating point distribution, Raspbian "pisces" (http://www.raspbian.org/PiscesImages) and applying the patches in https://gist.github.com/3116118, here are the results of the Eleanor McHugh gospeed benchmark:

```
raspbian@pisces:~/gowork/src/github.com/feyeleanor/gospeed$ uname -a
Linux pisces 3.1.9+ #171 PREEMPT Tue Jul 17 01:08:22 BST 2012 armv6l GNU/Linux
raspbian@pisces:~/gowork/src/github.com/feyeleanor/gospeed$ go test -test.bench=".*"
PASS
BenchmarkBaselineCastInt32ToInt	100000000	        13.5 ns/op
BenchmarkBaselineCastIntToInt32	100000000	        13.5 ns/op
BenchmarkBaselineCastInt64ToUint64	100000000	        17.8 ns/op
BenchmarkBaselineCastUint64ToInt64	100000000	        17.2 ns/op
BenchmarkBaselineVariableGet	100000000	        13.4 ns/op
BenchmarkBaselineVariableSet	100000000	        22.4 ns/op
BenchmarkBaselineVariableGetInterface	100000000	        13.5 ns/op
BenchmarkBaselineVariableSetInterface	50000000	        31.3 ns/op
BenchmarkBaselineVariableIncrement	100000000	        23.9 ns/op
BenchmarkBaselineVariableDecrement	100000000	        23.9 ns/op
BenchmarkBaselineFieldGet	100000000	        13.5 ns/op
BenchmarkBaselineFieldSet	100000000	        20.9 ns/op
BenchmarkBaselineSliceGet	50000000	        32.9 ns/op
BenchmarkBaselineSliceSet	50000000	        34.5 ns/op
BenchmarkBaselineMapIntGet	 1000000	      1448 ns/op
BenchmarkBaselineMapIntSet	 1000000	      1968 ns/op
BenchmarkBaselineMapStringGet	 1000000	      1119 ns/op
BenchmarkBaselineMapStringSet	 1000000	      1675 ns/op
BenchmarkBaselineIf	100000000	        15.0 ns/op
BenchmarkBaselineIfElse	100000000	        15.0 ns/op
BenchmarkBaselineSwitchDefault	100000000	        13.5 ns/op
BenchmarkBaselineSwitchOneCase	100000000	        15.0 ns/op
BenchmarkBaselineSwitchTwoCases	100000000	        18.0 ns/op
BenchmarkBaselineSwitchTwoCasesFallthrough	100000000	        18.0 ns/op
BenchmarkBaselineForLoopIteration	50000000	        42.0 ns/op
BenchmarkBaselineForReverseLoopIteration	50000000	        36.0 ns/op
BenchmarkBaselineForRange	20000000	        80.9 ns/op
BenchmarkBaselineForSliceLength	50000000	        39.0 ns/op
BenchmarkBaselineForReverseSliceLength	50000000	        36.0 ns/op
BenchmarkBaselineForLoopIteration10	20000000	       119 ns/op
BenchmarkBaselineForReverseLoopIteration10	20000000	        92.9 ns/op
BenchmarkBaselineForRange10	10000000	       215 ns/op
BenchmarkBaselineForSliceLength10	20000000	       109 ns/op
BenchmarkBaselineForReverseSliceLength10	20000000	        92.9 ns/op
BenchmarkBaselineForLoopIteration100	 2000000	       929 ns/op
BenchmarkBaselineForReverseLoopIteration100	 5000000	       700 ns/op
BenchmarkBaselineForRange100	 1000000	      1567 ns/op
BenchmarkBaselineForSliceLength100	 2000000	       853 ns/op
BenchmarkBaselineForReverseSliceLength100	 5000000	       700 ns/op
BenchmarkBaselineForLoopIteration10000	   10000	    106006 ns/op
BenchmarkBaselineForReverseLoopIteration10000	   50000	     67480 ns/op
BenchmarkBaselineForRange10000	   10000	    153841 ns/op
BenchmarkBaselineForSliceLength10000	   20000	     85735 ns/op
BenchmarkBaselineForReverseSliceLength10000	   50000	     69461 ns/op
BenchmarkBaselineMakeChannelBoolUnbuffered	  200000	     10162 ns/op
BenchmarkBaselineMakeChannelBool1	  200000	     12517 ns/op
BenchmarkBaselineMakeChannelBool10	  200000	     12521 ns/op
BenchmarkBaselineMakeChannelStringUnbuffered	  500000	     10369 ns/op
BenchmarkBaselineMakeChannelString1	  200000	     12576 ns/op
BenchmarkBaselineMakeChannelString10	  100000	     22358 ns/op
BenchmarkBaselineGo	   50000	    367593 ns/op
BenchmarkBaselineFunctionCall	50000000	        57.0 ns/op
BenchmarkBaselineFunctionCallArg	20000000	        81.0 ns/op
BenchmarkBaselineFunctionCall5VarArgs	  500000	      6852 ns/op
BenchmarkBaselineFunctionCallInt	50000000	        60.3 ns/op
BenchmarkBaselineFunctionCall5VarInts	 1000000	      3185 ns/op
BenchmarkBaselineFunctionCallWithDefer	 1000000	      2330 ns/op
BenchmarkBaselineFunctionCallPanicRecover	  500000	      6222 ns/op
BenchmarkBaselineMethodCallDirect	20000000	        83.8 ns/op
BenchmarkBaselineMethodCallDirect1Arg	20000000	       106 ns/op
BenchmarkBaselineMethodCallDirect1Int	20000000	        85.2 ns/op
BenchmarkBaselineMethodCallDirect5Args	 5000000	       368 ns/op
BenchmarkBaselineMethodCallDirect5Ints	10000000	       233 ns/op
BenchmarkBaselineMethodCallIndirect	100000000	        18.0 ns/op
BenchmarkBaselineMethodCallIndirect1Arg	50000000	        42.0 ns/op
BenchmarkBaselineMethodCallIndirect1Int	100000000	        19.5 ns/op
BenchmarkBaselineMethodCallIndirect5Args	 5000000	       309 ns/op
BenchmarkBaselineMethodCallIndirect5Ints	10000000	       168 ns/op
BenchmarkBaselineTypeAssertion	10000000	       218 ns/op
BenchmarkBaselineTypeAssertionEmptyInterface	20000000	       106 ns/op
BenchmarkBaselineTypeAssertionInterface1	 5000000	       576 ns/op
BenchmarkBaselineTypeAssertionInterface2	 5000000	       579 ns/op
BenchmarkBaselineTypeReflectPrimitiveToValue	 5000000	       425 ns/op
BenchmarkBaselineTypeReflectSliceToValue	 1000000	      3218 ns/op
BenchmarkBaselineTypeReflectStructToValue	  500000	      4760 ns/op
BenchmarkBaselineTypeCheck	10000000	       189 ns/op
BenchmarkBaselineTypeCheckEmptyInterface	20000000	        93.1 ns/op
BenchmarkBaselineTypeCheckInterface1	 5000000	       511 ns/op
BenchmarkBaselineTypeCheckInterface2	 5000000	       516 ns/op
BenchmarkBaselineTypeSwitchOneCase	10000000	       262 ns/op
BenchmarkBaselineTypeSwitchBasicTypesCase	10000000	       295 ns/op
BenchmarkBaselineTypeSwitchEmptyInterface	10000000	       163 ns/op
BenchmarkBaselineTypeSwitchInterface1	 5000000	       588 ns/op
BenchmarkBaselineTypeSwitchInterface2	 5000000	       602 ns/op
BenchmarkBaselineNewStructureLiteral	20000000	        84.0 ns/op
BenchmarkBaselineNewStructure	20000000	       127 ns/op
BenchmarkBaselineNewSliceLiteral	50000000	        54.2 ns/op
BenchmarkBaselineNewSlice	 1000000	      3124 ns/op
BenchmarkBaselineNewMapLiteralIntToInt	  500000	      9083 ns/op
BenchmarkBaselineNewMapLiteralIntToInterface	  500000	      9807 ns/op
BenchmarkBaselineNewMapLiteralStringToInt	  500000	      9792 ns/op
BenchmarkBaselineNewMapLiteralStringToInterface	  500000	     10595 ns/op
BenchmarkBaselineNewMapLiteralIntToInt2Item	  200000	     14265 ns/op
BenchmarkBaselineNewMapLiteralIntToInterface2Item	  200000	     14669 ns/op
BenchmarkBaselineNewMapLiteralStringToInt2Item	  200000	     14025 ns/op
BenchmarkBaselineNewMapLiteralStringToInterface2Item	  200000	     15086 ns/op
BenchmarkBaselineNewMapIntToInt	  500000	      9025 ns/op
BenchmarkBaselineNewMapIntToInterface	  500000	      9753 ns/op
BenchmarkBaselineNewMapStringToInt	  500000	      9740 ns/op
BenchmarkBaselineNewMapStringToInterface	  500000	     10486 ns/op
BenchmarkBaselineSliceCopy	 5000000	       300 ns/op
BenchmarkBaselineNewSliceAppendElement1	 1000000	      3318 ns/op
BenchmarkBaselineNewSliceAppendElement10	 1000000	      5174 ns/op
ok  	github.com/feyeleanor/gospeed	417.296s
```

_-- anthony starks_

## Raspberry Pi Zero

Architecture: 1 GHz ARM1176JZF-S, running at 700Mhz; 512MB RAM

Operating System: Raspbian Jessie

```
$ go version
go version devel +5c24832 Sat Dec 5 00:10:40 2015 +0000 linux/arm

$ go test -timeout 20m -v -bench=Benchmark -run=X
PASS
BenchmarkAppend                        3000000         518 ns/op
BenchmarkAppendGrowByte                     20    95720661 ns/op
BenchmarkAppendGrowString                    1  2232033275 ns/op
BenchmarkAppend1Byte                  20000000          99.0 ns/op
BenchmarkAppend4Bytes                 10000000         120 ns/op
BenchmarkAppend7Bytes                 10000000         155 ns/op
BenchmarkAppend8Bytes                 10000000         132 ns/op
BenchmarkAppend15Bytes                10000000         162 ns/op
BenchmarkAppend16Bytes                10000000         134 ns/op
BenchmarkAppend32Bytes                10000000         121 ns/op
BenchmarkAppendStr1Byte               20000000          97.0 ns/op
BenchmarkAppendStr4Bytes              10000000         118 ns/op
BenchmarkAppendStr8Bytes              10000000         129 ns/op
BenchmarkAppendStr16Bytes             10000000         132 ns/op
BenchmarkAppendStr32Bytes             10000000         121 ns/op
BenchmarkAppendSpecialCase             2000000         791 ns/op
BenchmarkCopy1Byte                    10000000         132 ns/op     7.54 MB/s
BenchmarkCopy2Byte                    10000000         144 ns/op    13.81 MB/s
BenchmarkCopy4Byte                    10000000         153 ns/op    26.12 MB/s
BenchmarkCopy8Byte                    10000000         164 ns/op    48.51 MB/s
BenchmarkCopy12Byte                   10000000         162 ns/op    74.03 MB/s
BenchmarkCopy16Byte                   10000000         167 ns/op    95.63 MB/s
BenchmarkCopy32Byte                   10000000         155 ns/op   205.20 MB/s
BenchmarkCopy128Byte                  10000000         192 ns/op   664.06 MB/s
BenchmarkCopy1024Byte                  2000000         689 ns/op  1484.28 MB/s
BenchmarkCopy1String                  10000000         120 ns/op     8.27 MB/s
BenchmarkCopy2String                  10000000         134 ns/op    14.85 MB/s
BenchmarkCopy4String                  10000000         142 ns/op    28.01 MB/s
BenchmarkCopy8String                  10000000         154 ns/op    51.81 MB/s
BenchmarkCopy12String                 10000000         151 ns/op    79.01 MB/s
BenchmarkCopy16String                 10000000         157 ns/op   101.82 MB/s
BenchmarkCopy32String                 10000000         145 ns/op   219.52 MB/s
BenchmarkCopy128String                10000000         182 ns/op   700.88 MB/s
BenchmarkCopy1024String                2000000         976 ns/op  1048.87 MB/s
BenchmarkChanNonblocking               5000000         246 ns/op
BenchmarkSelectUncontended              500000        3610 ns/op
BenchmarkSelectSyncContended            100000       18957 ns/op
BenchmarkSelectAsyncContended           500000        3614 ns/op
BenchmarkSelectNonblock                2000000         814 ns/op
BenchmarkChanUncontended                 10000      135820 ns/op
BenchmarkChanContended                   10000      133122 ns/op
BenchmarkChanSync                       200000        5870 ns/op
BenchmarkChanProdCons0                  200000        5899 ns/op
BenchmarkChanProdCons10                 500000        2138 ns/op
BenchmarkChanProdCons100               1000000        1557 ns/op
BenchmarkChanProdConsWork0              200000        8948 ns/op
BenchmarkChanProdConsWork10             300000        5043 ns/op
BenchmarkChanProdConsWork100            300000        4498 ns/op
BenchmarkSelectProdCons                 200000       10818 ns/op
BenchmarkChanCreation                   500000        3187 ns/op
BenchmarkChanSem                       1000000        1266 ns/op
BenchmarkChanPopular                       100    14315946 ns/op
BenchmarkCallClosure                  30000000          50.0 ns/op
BenchmarkCallClosure1                 30000000          56.3 ns/op
BenchmarkCallClosure2                  3000000         512 ns/op
BenchmarkCallClosure3                  3000000         503 ns/op
BenchmarkCallClosure4                  3000000         512 ns/op
BenchmarkComplex128DivNormal           2000000         735 ns/op
BenchmarkComplex128DivNisNaN            200000        6001 ns/op
BenchmarkComplex128DivDisNaN            200000        5992 ns/op
BenchmarkComplex128DivNisInf           5000000         390 ns/op
BenchmarkComplex128DivDisInf           5000000         375 ns/op
BenchmarkSetTypePtr                   10000000         119 ns/op    33.43 MB/s
BenchmarkSetTypePtr8                  10000000         227 ns/op   140.89 MB/s
BenchmarkSetTypePtr16                  5000000         285 ns/op   224.30 MB/s
BenchmarkSetTypePtr32                  5000000         388 ns/op   329.65 MB/s
BenchmarkSetTypePtr64                  3000000         591 ns/op   432.77 MB/s
BenchmarkSetTypePtr126                 1000000        1021 ns/op   493.46 MB/s
BenchmarkSetTypePtr128                 1000000        1003 ns/op   510.46 MB/s
BenchmarkSetTypePtrSlice                200000        7427 ns/op   551.43 MB/s
BenchmarkSetTypeNode1                 10000000         217 ns/op    55.20 MB/s
BenchmarkSetTypeNode1Slice             1000000        1284 ns/op   299.03 MB/s
BenchmarkSetTypeNode8                  5000000         277 ns/op   144.17 MB/s
BenchmarkSetTypeNode8Slice              500000        2825 ns/op   453.02 MB/s
BenchmarkSetTypeNode64                 2000000         661 ns/op   398.89 MB/s
BenchmarkSetTypeNode64Slice             100000       15531 ns/op   543.92 MB/s
BenchmarkSetTypeNode64Dead             5000000         382 ns/op   689.66 MB/s
BenchmarkSetTypeNode64DeadSlice         100000       13252 ns/op   637.46 MB/s
BenchmarkSetTypeNode124                1000000        1017 ns/op   495.27 MB/s
BenchmarkSetTypeNode124Slice             50000       28139 ns/op   573.14 MB/s
BenchmarkSetTypeNode126                2000000        1001 ns/op   511.10 MB/s
BenchmarkSetTypeNode126Slice             50000       26535 ns/op   617.43 MB/s
BenchmarkSetTypeNode128                1000000        1087 ns/op   478.22 MB/s
BenchmarkSetTypeNode128Slice             50000       29166 ns/op   570.52 MB/s
BenchmarkSetTypeNode130                1000000        1067 ns/op   494.83 MB/s
BenchmarkSetTypeNode130Slice             50000       29691 ns/op   569.04 MB/s
BenchmarkSetTypeNode1024                200000        7155 ns/op   573.51 MB/s
BenchmarkSetTypeNode1024Slice             5000      224292 ns/op   585.52 MB/s
BenchmarkAllocation                       2000      957094 ns/op
BenchmarkHash5                         5000000         349 ns/op    14.29 MB/s
BenchmarkHash16                        3000000         436 ns/op    36.66 MB/s
BenchmarkHash64                        1000000        1007 ns/op    63.49 MB/s
BenchmarkHash1024                       200000       11267 ns/op    90.88 MB/s
BenchmarkHash65536                        2000      797741 ns/op    82.15 MB/s
BenchmarkEqEfaceConcrete              20000000         111 ns/op
BenchmarkEqIfaceConcrete              20000000         106 ns/op
BenchmarkNeEfaceConcrete              20000000         111 ns/op
BenchmarkNeIfaceConcrete              20000000         106 ns/op
BenchmarkConvT2ESmall                  3000000         561 ns/op
BenchmarkConvT2EUintptr                2000000         599 ns/op
BenchmarkConvT2ELarge                  2000000         767 ns/op
BenchmarkConvT2ISmall                  2000000         724 ns/op
BenchmarkConvT2IUintptr                2000000         750 ns/op
BenchmarkConvT2ILarge                  2000000         907 ns/op
BenchmarkConvI2E                      20000000          76.7 ns/op
BenchmarkConvI2I                       3000000         425 ns/op
BenchmarkAssertE2T                    10000000         176 ns/op
BenchmarkAssertE2TLarge               10000000         189 ns/op
BenchmarkAssertE2I                     3000000         455 ns/op
BenchmarkAssertI2T                    10000000         176 ns/op
BenchmarkAssertI2I                     3000000         451 ns/op
BenchmarkAssertI2E                    20000000         109 ns/op
BenchmarkAssertE2E                    30000000          40.7 ns/op
BenchmarkAssertE2T2                   10000000         180 ns/op
BenchmarkAssertE2T2Blank              50000000          22.8 ns/op
BenchmarkAssertI2E2                   20000000         117 ns/op
BenchmarkAssertI2E2Blank              100000000         21.7 ns/op
BenchmarkAssertE2E2                   10000000         231 ns/op
BenchmarkAssertE2E2Blank              100000000         21.8 ns/op
BenchmarkMalloc8                       3000000         507 ns/op
BenchmarkMalloc16                      2000000         848 ns/op
BenchmarkMallocTypeInfo8               2000000        1012 ns/op
BenchmarkMallocTypeInfo16              1000000        1168 ns/op
BenchmarkMallocLargeStruct              500000        4823 ns/op
BenchmarkGoroutineSelect                    20    76172338 ns/op
BenchmarkGoroutineBlocking                  20    63469806 ns/op
BenchmarkGoroutineForRange                  20    64107650 ns/op
BenchmarkGoroutineIdle                      20    60844381 ns/op
BenchmarkMapPop100                        3000      409498 ns/op
BenchmarkMapPop1000                        200     7783817 ns/op
BenchmarkMapPop10000                        10   170736704 ns/op
BenchmarkHashStringSpeed               3000000         541 ns/op
BenchmarkHashBytesSpeed                1000000        1157 ns/op
BenchmarkHashInt32Speed                5000000         371 ns/op
BenchmarkHashInt64Speed                3000000         427 ns/op
BenchmarkHashStringArraySpeed          1000000        1417 ns/op
BenchmarkMegMap                        3000000         404 ns/op
BenchmarkMegOneMap                     5000000         346 ns/op
BenchmarkMegEqMap                          100    16663414 ns/op
BenchmarkMegEmptyMap                  10000000         160 ns/op
BenchmarkSmallStrMap                   3000000         415 ns/op
BenchmarkMapStringKeysEight_16         3000000         417 ns/op
BenchmarkMapStringKeysEight_32         3000000         420 ns/op
BenchmarkMapStringKeysEight_64         3000000         420 ns/op
BenchmarkMapStringKeysEight_1M         3000000         419 ns/op
BenchmarkIntMap                       10000000         220 ns/op
BenchmarkRepeatedLookupStrMapKey32     1000000        1015 ns/op
BenchmarkRepeatedLookupStrMapKey1M         100    15652033 ns/op
BenchmarkNewEmptyMap                   1000000        1395 ns/op         0 B/op        0 allocs/op
BenchmarkNewSmallMap                    300000        3368 ns/op         0 B/op        0 allocs/op
BenchmarkMapIter                        500000        2947 ns/op
BenchmarkMapIterEmpty                 20000000         163 ns/op
BenchmarkSameLengthMap                10000000         133 ns/op
BenchmarkBigKeyMap                     2000000         899 ns/op
BenchmarkBigValMap                     2000000         922 ns/op
BenchmarkSmallKeyMap                   3000000         402 ns/op
BenchmarkComplexAlgMap                 1000000        2003 ns/op
BenchmarkMemmove0                     20000000          61.4 ns/op
BenchmarkMemmove1                     20000000          76.6 ns/op    13.05 MB/s
BenchmarkMemmove2                     20000000          86.3 ns/op    23.18 MB/s
BenchmarkMemmove3                     20000000          83.7 ns/op    35.83 MB/s
BenchmarkMemmove4                     20000000          88.0 ns/op    45.48 MB/s
BenchmarkMemmove5                     20000000         110 ns/op    45.37 MB/s
BenchmarkMemmove6                     20000000         115 ns/op    51.99 MB/s
BenchmarkMemmove7                     10000000         123 ns/op    56.89 MB/s
BenchmarkMemmove8                     20000000          99.5 ns/op    80.44 MB/s
BenchmarkMemmove9                     20000000         112 ns/op    79.76 MB/s
BenchmarkMemmove10                    10000000         125 ns/op    79.48 MB/s
BenchmarkMemmove11                    10000000         125 ns/op    87.84 MB/s
BenchmarkMemmove12                    20000000          96.9 ns/op   123.87 MB/s
BenchmarkMemmove13                    20000000         110 ns/op   117.83 MB/s
BenchmarkMemmove14                    10000000         123 ns/op   113.65 MB/s
BenchmarkMemmove15                    10000000         122 ns/op   122.30 MB/s
BenchmarkMemmove16                    20000000         101 ns/op   156.89 MB/s
BenchmarkMemmove32                    20000000          90.8 ns/op   352.44 MB/s
BenchmarkMemmove64                    20000000         108 ns/op   588.34 MB/s
BenchmarkMemmove128                   10000000         127 ns/op  1001.83 MB/s
BenchmarkMemmove256                   10000000         178 ns/op  1436.19 MB/s
BenchmarkMemmove512                    5000000         326 ns/op  1569.07 MB/s
BenchmarkMemmove1024                   2000000         631 ns/op  1620.84 MB/s
BenchmarkMemmove2048                   1000000        1251 ns/op  1636.60 MB/s
BenchmarkMemmove4096                    500000        2499 ns/op  1638.97 MB/s
BenchmarkMemmoveUnaligned0            20000000          72.5 ns/op
BenchmarkMemmoveUnaligned1            20000000          87.8 ns/op    11.39 MB/s
BenchmarkMemmoveUnaligned2            20000000          99.4 ns/op    20.12 MB/s
BenchmarkMemmoveUnaligned3            20000000          96.9 ns/op    30.96 MB/s
BenchmarkMemmoveUnaligned4            10000000         135 ns/op    29.44 MB/s
BenchmarkMemmoveUnaligned5            10000000         147 ns/op    33.90 MB/s
BenchmarkMemmoveUnaligned6            10000000         146 ns/op    41.09 MB/s
BenchmarkMemmoveUnaligned7            10000000         151 ns/op    46.27 MB/s
BenchmarkMemmoveUnaligned8            10000000         156 ns/op    51.22 MB/s
BenchmarkMemmoveUnaligned9            10000000         161 ns/op    55.82 MB/s
BenchmarkMemmoveUnaligned10           10000000         166 ns/op    60.09 MB/s
BenchmarkMemmoveUnaligned11           10000000         171 ns/op    64.17 MB/s
BenchmarkMemmoveUnaligned12           10000000         177 ns/op    67.79 MB/s
BenchmarkMemmoveUnaligned13           10000000         181 ns/op    71.60 MB/s
BenchmarkMemmoveUnaligned14           10000000         189 ns/op    74.03 MB/s
BenchmarkMemmoveUnaligned15           10000000         196 ns/op    76.30 MB/s
BenchmarkMemmoveUnaligned16           10000000         200 ns/op    79.91 MB/s
BenchmarkMemmoveUnaligned32           10000000         221 ns/op   144.64 MB/s
BenchmarkMemmoveUnaligned64            5000000         290 ns/op   220.16 MB/s
BenchmarkMemmoveUnaligned128           3000000         413 ns/op   309.84 MB/s
BenchmarkMemmoveUnaligned256           2000000         766 ns/op   334.16 MB/s
BenchmarkMemmoveUnaligned512           2000000         925 ns/op   553.13 MB/s
BenchmarkMemmoveUnaligned1024           500000        2747 ns/op   372.66 MB/s
BenchmarkMemmoveUnaligned2048           500000        3180 ns/op   643.85 MB/s
BenchmarkMemmoveUnaligned4096           200000        6206 ns/op   659.99 MB/s
BenchmarkMemclr5                      20000000         105 ns/op    47.53 MB/s
BenchmarkMemclr16                     20000000         110 ns/op   144.77 MB/s
BenchmarkMemclr64                     10000000         125 ns/op   511.58 MB/s
BenchmarkMemclr256                    10000000         182 ns/op  1402.34 MB/s
BenchmarkMemclr4096                     500000        2489 ns/op  1645.22 MB/s
BenchmarkMemclr65536                     50000       39883 ns/op  1643.18 MB/s
BenchmarkMemclr1M                         2000      636812 ns/op  1646.60 MB/s
BenchmarkMemclr4M                          500     2549362 ns/op  1645.24 MB/s
BenchmarkMemclr8M                          300     5162451 ns/op  1624.93 MB/s
BenchmarkMemclr16M                         200    10300878 ns/op  1628.72 MB/s
BenchmarkMemclr64M                          30    42801198 ns/op  1567.92 MB/s
BenchmarkGoMemclr5                    20000000          73.5 ns/op    67.99 MB/s
BenchmarkGoMemclr16                   20000000          85.9 ns/op   186.24 MB/s
BenchmarkGoMemclr64                   20000000          87.8 ns/op   729.24 MB/s
BenchmarkGoMemclr256                  10000000         160 ns/op  1591.97 MB/s
BenchmarkClearFat8                    100000000         15.6 ns/op
BenchmarkClearFat12                   100000000         27.5 ns/op
BenchmarkClearFat16                   100000000         32.4 ns/op
BenchmarkClearFat24                   50000000          57.0 ns/op
BenchmarkClearFat32                   50000000          80.5 ns/op
BenchmarkClearFat40                   30000000          77.5 ns/op
BenchmarkClearFat48                   30000000         105 ns/op
BenchmarkClearFat56                   20000000          87.1 ns/op
BenchmarkClearFat64                   20000000         137 ns/op
BenchmarkClearFat128                  20000000         278 ns/op
BenchmarkClearFat256                   5000000         537 ns/op
BenchmarkClearFat512                   2000000        1293 ns/op
BenchmarkClearFat1024                  1000000        2545 ns/op
BenchmarkCopyFat8                     100000000         12.2 ns/op
BenchmarkCopyFat12                    100000000         20.3 ns/op
BenchmarkCopyFat16                    100000000         34.3 ns/op
BenchmarkCopyFat24                    50000000          27.7 ns/op
BenchmarkCopyFat32                    50000000          25.4 ns/op
BenchmarkCopyFat64                    20000000         135 ns/op
BenchmarkCopyFat128                   10000000         299 ns/op
BenchmarkCopyFat256                    2000000         571 ns/op
BenchmarkCopyFat512                    1000000        1218 ns/op
BenchmarkCopyFat1024                    500000        2665 ns/op
BenchmarkFinalizer                          50    20313669 ns/op
BenchmarkFinalizerRun                    30000       49987 ns/op
BenchmarkSyscall                       1000000        1625 ns/op
BenchmarkSyscallWork                    500000        2668 ns/op
BenchmarkSyscallExcess                 1000000        1613 ns/op
BenchmarkSyscallExcessWork              500000        2658 ns/op
BenchmarkPingPongHog                    100000       20539 ns/op
BenchmarkStackGrowth                     50000       28473 ns/op
BenchmarkStackGrowthDeep                   500     2845263 ns/op
BenchmarkCreateGoroutines               300000        4297 ns/op
BenchmarkCreateGoroutinesParallel       300000        4300 ns/op
BenchmarkCreateGoroutinesCapture         50000       33218 ns/op        16 B/op        1 allocs/op
BenchmarkClosureCall                  30000000          55.1 ns/op
BenchmarkMatmult                      10000000         196 ns/op
BenchmarkIfaceCmp100                    500000        2672 ns/op
BenchmarkIfaceCmpNil100                 500000        2982 ns/op
BenchmarkDefer                         1000000        1819 ns/op
BenchmarkDefer10                       1000000        1478 ns/op
BenchmarkDeferMany                      500000        3464 ns/op
BenchmarkStackCopy                           1  3714828065 ns/op
BenchmarkCompareStringEqual           10000000         160 ns/op
BenchmarkCompareStringIdentical       30000000          54.1 ns/op
BenchmarkCompareStringSameLength      20000000         111 ns/op
BenchmarkCompareStringDifferentLength 100000000         16.3 ns/op
BenchmarkCompareStringBigUnaligned         100    16695582 ns/op    62.81 MB/s
BenchmarkCompareStringBig                  100    17208318 ns/op    60.93 MB/s
BenchmarkRuneIterate                    300000        5159 ns/op
BenchmarkRuneIterate2                   300000        5158 ns/op
BenchmarkUint32Div7                   10000000         144 ns/op
BenchmarkUint32Div37                  10000000         144 ns/op
BenchmarkUint32Div123                 10000000         144 ns/op
BenchmarkUint32Div763                 10000000         148 ns/op
BenchmarkUint32Div1247                10000000         144 ns/op
BenchmarkUint32Div9305                10000000         144 ns/op
BenchmarkUint32Div13307               10000000         144 ns/op
BenchmarkUint32Div52513               10000000         144 ns/op
BenchmarkUint32Div60978747            10000000         131 ns/op
BenchmarkUint32Div106956295           10000000         131 ns/op
BenchmarkUint32Mod7                   10000000         144 ns/op
BenchmarkUint32Mod37                  10000000         144 ns/op
BenchmarkUint32Mod123                 10000000         144 ns/op
BenchmarkUint32Mod763                 10000000         144 ns/op
BenchmarkUint32Mod1247                10000000         144 ns/op
BenchmarkUint32Mod9305                10000000         144 ns/op
BenchmarkUint32Mod13307               10000000         144 ns/op
BenchmarkUint32Mod52513               10000000         144 ns/op
BenchmarkUint32Mod60978747            10000000         131 ns/op
BenchmarkUint32Mod106956295           10000000         131 ns/op
ok    runtime 566.969s
```

## ODROID-X

Architecture: ARMv7 quad-core Cortex-A9 (Samsung Exynos 4412 1.4GHz), 1GB RAM, Mali graphics (untested).

Operating System: [Archlinux ARM](http://archlinuxarm.org/)

Go pre-1.1 compiles out of the box. The four cores make it particularly suited to Go multi-threaded programs. An ODROID-X2 is coming (Nov 2012) with more RAM.

_-- Rémy Oudompheng_

## BananaPi

[BananaPi](http://bananapi.org) has a few enhanced hardware components compare with Raspberry Pi.

| **Architecture** | **Comments** |
|:-----------------|:-------------|
| [Allwinner A20(ARM Cortex-A7 Dual-core, 1GHz, Mali400MP2 GPU)](http://www.allwinnertech.com/en/clq/processora/A20.html) | tbc          |
| eSATA            | No worry to wear out your root SD Card|
| Onboard Microphone | tbc          |
| 1G Etherenet     | tbc          |
| 1G RAM           | tbc          |
| Reset Switch     | To reset the board ?|
| Power Switch     | To power cycle the board ?|

```
root@bpi01:/data/go13/src# cat ./buildgo.bash
#!/bin/bash
# use 1 CPU to avoid out of memory compilation issue.
time taskset 2 ./make.bash

root@bpi01:/data/go13/src# ./buildgo.bash

<snipped>

Installed Go for linux/arm in /data/go1.3
Installed commands in /data/go1.3/bin

real    9m9.222s
user    8m18.960s
sys     0m40.920s
root@bpi01:/data/go1.3/src#
```

_--T.J. Yang_

## AppliedMicro X-Gene (ARMv8)

Architecture: ARMv8 (64-bit) 8-core, 2.4GHz, 16GB RAM

Operating Systems: Linux, Fedora 21

You will need to cross-compile a toolchain using bootstrap.bash. After you copy it to the arm64 system and set `GOROOT_BOOTSTRAP`, you can build go natively.

## 96Boards HiKey (ARMv8)

Architecture: ARMv8 (64-bit) 8-core, 1.2GHz, 1GB RAM

Operating System: Linux (Linaro)

Go Version:  1.5Beta1

Special Notes:  Enable a swap partition (<=1GB is fine). Build process is CPU-intensive and may cause the internal 90C temperature threshold to be exceeded - keep the HiKey cool during the build.

As mentioned above, use bootstrap.sh (e.g. on Ubuntu AMD64) for ARM64, then transfer over the bootstrap tbx file, untar it, and use it as GOROOT_BOOTSTRAP.  Check out the Go sources into a separate GOROOT, and build.

_--Andrew Cencini_ (andrew@vapor.io)

## Scaleway C1 Server

Architecture: armv7l

Operating System: Debian 8.2 (armhf)

Go Version: 1.5

The Scaleway C1 Server is a dedicated ARM server with 2GiB RAM using a SAN for storage.

I used the following guide: [Building Go 1.5 on the Raspberry Pi](http://dave.cheney.net/2015/09/04/building-go-1-5-on-the-raspberry-pi)

_--Laurent Debacker