Add remark about target OS to cross-compilation instructions.

1 files changed, 13 insertions, 5 deletions

diff --git a/doc/install.html b/doc/install.html
index b43c472e..12f28d4f 100644
--- a/doc/install.html
+++ b/doc/install.html
@@ -102,9 +102,9 @@ operating system, CPU and compilers:
 <table class="compat">
 <tr class="compathead">
 <td class="compatcpu">CPU / OS</td>
-<td class="compatos"><a href="#posix">Linux</a><br><a href="#cross">or Android</a></td>
-<td class="compatos"><a href="#posix">OSX<br>10.3-10.6</a></td>
+<td class="compatos"><a href="#posix">Linux</a> or<br><a href="#cross">Android</a></td>
 <td class="compatos"><a href="#posix">*BSD, other</a></td>
+<td class="compatos"><a href="#posix">OSX<br>10.3-10.6</a></td>
 <td class="compatos"><a href="#windows">Windows<br>98/XP/Vista/7</a></td>
 </tr>
 <tr class="odd separate">
@@ -117,21 +117,21 @@ operating system, CPU and compilers:
 <tr class="even">
 <td class="compatcpu">x64 (64 bit)</td>
 <td class="compatos">GCC 4.x</td>
-<td class="compatos">GCC 4.x</td>
 <td class="compatos compatno">&nbsp;</td>
+<td class="compatos">GCC 4.x</td>
 <td class="compatos">MSVC + SDK v7.0<br>WinSDK v7.0</td>
 </tr>
 <tr class="odd">
 <td class="compatcpu">ARM</td>
 <td class="compatos">GCC 4.3+</td>
-<td class="compatos compatno">&nbsp;</td>
+<td class="compatos">GCC 4.3+</td>
 <td class="compatos compatno">&nbsp;</td>
 <td class="compatos compatno">&nbsp;</td>
 </tr>
 <tr class="even">
 <td class="compatcpu">PPC/e500v2</td>
 <td class="compatos">GCC 4.3+</td>
-<td class="compatos compatno">&nbsp;</td>
+<td class="compatos">GCC 4.3+</td>
 <td class="compatos compatno">&nbsp;</td>
 <td class="compatos compatno">&nbsp;</td>
 </tr>
@@ -342,6 +342,14 @@ installing the <tt>mingw32</tt> package and running:
 make HOST_CC="gcc -m32" CROSS=i586-mingw32msvc- TARGET_SYS=Windows
 </pre>
 <p>
+Whenever the <b>host OS and the target OS differ</b>, you need to specify
+<tt>TARGET_SYS</tt> or you'll get assembler or linker errors. E.g. if
+you're compiling on a Windows or OSX host for embedded Linux or Android,
+you need to add <tt>TARGET_SYS=Linux</tt> to the examples below. For a
+minimal target OS, you may need to disable the built-in allocator in
+<tt>src/Makefile</tt> and use <tt>TARGET_SYS=Other</tt>.
+</p>
+<p>
 You can cross-compile for an <b>ARM target</b> on an x86 or x64 host
 system using a standard GNU cross-compile toolchain (Binutils, GCC,
 EGLIBC). The <tt>CROSS</tt> prefix may vary depending on the