doc/install-source.html: recent ARM and 386 updates

R=golang-dev, dave, adg, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6845083

doc/install-source.html

@@ -57,7 +57,7 @@ architectures.
 	<code>arm</code> (a.k.a. <code>ARM</code>); <code>5g,5l,5c,5a</code>
 </dt>
 <dd>
-	Supports only Linux binaries. Less widely used than the other ports and therefore not as thoroughly tested.
+	Supports Linux, FreeBSD and NetBSD binaries. Less widely used than the other ports.
 </dd>
 </dl>
 
@@ -69,7 +69,7 @@ goroutines, such as stacks that grow and shrink on demand.
 </p>
 
 <p>
-The compilers can target the FreeBSD, Linux, NetBSD, OpenBSD, OS X (Darwin),
+The compilers can target the FreeBSD, Linux, NetBSD, OpenBSD, OS X (Darwin), Plan 9,
 and Windows operating systems.
 The full set of supported combinations is listed in the discussion of
 <a href="#environment">environment variables</a> below.
@@ -273,9 +273,8 @@ The Go compilation environment can be customized by environment variables.
 to override the defaults.
 </p>
 
-<blockquote>
-
-<p><code>$GOROOT</code></p>
+<ul>
+<li><code>$GOROOT</code>
 <p>
 The root of the Go tree, often <code>$HOME/go</code>.
 Its value is built into the tree when it is compiled, and
@@ -284,7 +283,7 @@ There is no need to set this unless you want to switch between multiple
 local copies of the repository.
 </p>
 
-<p><code>$GOROOT_FINAL</code></p>
+<li><code>$GOROOT_FINAL</code>
 <p>
 The value assumed by installed binaries and scripts when
 <code>$GOROOT</code> is not set explicitly.
@@ -294,7 +293,7 @@ but move it elsewhere after the build, set
 <code>$GOROOT_FINAL</code> to the eventual location.
 </p>
 
-<p><code>$GOOS</code> and <code>$GOARCH</code></p>
+<li><code>$GOOS</code> and <code>$GOARCH</code>
 <p>
 The name of the target operating system and compilation architecture.
 These default to the values of <code>$GOHOSTOS</code> and
@@ -311,7 +310,7 @@ Choices for <code>$GOARCH</code> are
 The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 <table cellpadding="0">
 <tr>
-<th width="50"><th align="left" width="100"><code>$GOOS</code></th> <th align="left" width="100"><code>$GOARCH</code></th> <th align="left"></th>
+<th width="50"></th><th align="left" width="100"><code>$GOOS</code></th> <th align="left" width="100"><code>$GOARCH</code></th>
 </tr>
 <tr>
 <td></td><td><code>darwin</code></td> <td><code>386</code></td>
@@ -326,6 +325,9 @@ The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 <td></td><td><code>freebsd</code></td> <td><code>amd64</code></td>
 </tr>
 <tr>
+<td></td><td><code>freebsd</code></td> <td><code>arm</code></td>
+</tr>
+<tr>
 <td></td><td><code>linux</code></td> <td><code>386</code></td>
 </tr>
 <tr>
@@ -341,6 +343,9 @@ The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 <td></td><td><code>netbsd</code></td> <td><code>amd64</code></td>
 </tr>
 <tr>
+<td></td><td><code>netbsd</code></td> <td><code>arm</code></td>
+</tr>
+<tr>
 <td></td><td><code>openbsd</code></td> <td><code>386</code></td>
 </tr>
 <tr>
@@ -350,6 +355,9 @@ The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 <td></td><td><code>plan9</code></td> <td><code>386</code></td>
 </tr>
 <tr>
+<td></td><td><code>plan9</code></td> <td><code>amd64</code></td>
+</tr>
+<tr>
 <td></td><td><code>windows</code></td> <td><code>386</code></td>
 </tr>
 <tr>
@@ -357,7 +365,7 @@ The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 </tr>
 </table>
 
-<p><code>$GOHOSTOS</code> and <code>$GOHOSTARCH</code></p>
+<li><code>$GOHOSTOS</code> and <code>$GOHOSTARCH</code>
 <p>
 The name of the host operating system and compilation architecture.
 These default to the local system's operating system and
@@ -372,7 +380,7 @@ For example, you should not set <code>$GOHOSTARCH</code> to
 <code>arm</code> on an x86 system.
 </p>
 
-<p><code>$GOBIN</code>
+<li><code>$GOBIN</code>
 <p>
 The location where Go binaries will be installed.
 The default is <code>$GOROOT/bin</code>.
@@ -382,15 +390,38 @@ If <code>$GOBIN</code> is set, the <a href="/cmd/go">go command</a>
 installs all commands there.
 </p>
 
-<p><code>$GOARM</code> (arm, default=6)</p>
+<li><code>$GO386</code> (for <code>386</code> only, default is auto-detected
+if built natively, <code>387</code> if not)
+<p>
+This controls the code generated by 8g to use either the 387 floating-point unit
+(set to <code>387</code>) or SSE2 instructions (set to <code>sse2</code>) for
+floating point computations.
+</p>
+<ul>
+	<li><code>GO386=387</code>: use x87 for floating point operations; should support all x86 chips (Pentium MMX or later).
+	<li><code>GO386=sse2</code>: use SSE2 for floating point operations; has better performance than 387, but only available on Pentium 4/Opteron/Athlon 64 or later.
+</ul>
+
+<li><code>$GOARM</code> (for <code>arm</code> only; default is auto-detected if building
+on the target processor, 6 if not)
+<p>
+This sets the ARM floating point co-processor architecture version the run-time
+should target. If you are compiling on the target system, its value will be auto-detected.
+</p>
+<ul>
+	<li><code>GOARM=5</code>: use software floating point; when CPU doesn't have VFP co-processor
+	<li><code>GOARM=6</code>: use VFPv1 only; default if cross compiling; usually ARM11 or better cores (VFPv2 or better is also supported)
+	<li><code>GOARM=7</code>: use VFPv3; usually Cortex-A cores
+</ul>
 <p>
-The ARM architecture version the run-time libraries should target.
-Setting <code>$GOARM</code> to 5 causes the linker to emit calls
-to a software floating point implementation instead of using
-hardware floating point support.
+If in doubt, leave this variable unset, and adjust it if required
+when you first run the Go executable.
+The <a href="http://code.google.com/p/go-wiki/wiki/GoArm">GoARM</a> page
+on the <a href="http://code.google.com/p/go-wiki/w/list">Go community wiki</a>
+contains further details regarding Go's ARM support.
 </p>
 
-</blockquote>
+</ul>
 
 <p>
 Note that <code>$GOARCH</code> and <code>$GOOS</code> identify the