add cross compilation docs for english

2 files changed, 191 insertions, 7 deletions

diff --git a/docs/README.md b/docs/README.md
index 29738c7a1..d235a93a9 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -137,6 +137,16 @@ hello`main:
 
 ## Configuration
 
+Set compilation configuration before building project with command `xmake f|config`.
+And if you want to known more options, please run: `xmake f --help`。
+
+<p class="tip">
+    You can use short or long command option, for exmaple: <br>
+    `xmake f` or `xmake config`.<br>
+    `xmake f -p linux` or `xmake config --plat=linux`.<br>
+    `xmake f -p linux -a i386` or `xmake config --plat=linux --arch=i386`.
+</p>
+
 #### Target Platforms
 
 ##### Current Host
@@ -163,6 +173,20 @@ $ xmake f -p android --ndk=~/files/android-ndk-r10e/ [-a armv5te|armv6|armv7-a|a
 $ xmake
 ```
 
+If you want to set the other android toolchains, you can use [--toolchains](#-toolchains) option.
+
+For example:
+
+```bash
+$ xmake f -p android --ndk=~/files/android-ndk-r10e/ -a arm64-v8a --toolchains=~/files/android-ndk-r10e/toolchains/aarch64-linux-android-4.9/prebuilt/darwin-x86_64/bin
+```
+
+The [--toolchains](#-toolchains) option is used to set `bin` directory of toolchains.
+    
+<p class="tip">
+Please attempt to set `--arch=` option if it had failed to check compiler.
+</p>
+
 ##### iPhoneOS
 
 ```bash
@@ -198,15 +222,175 @@ $ xmake f -p linux --sdk=/usr/local/arm-linux-gcc/ [--toolchains=/sdk/bin] [--cr
 $ xmake
 ``` 
 
+| Configuration Option         | Description                                  |
+| ---------------------------- | -------------------------------------------- |
+| [--sdk](#-sdk)               | Set the sdk root directory of toolchains     |
+| [--toolchains](#-toolchains) | Set the `bin` directory of toolchains        |
+| [--cross](#-cross)           | Set the prefix of compilation tools          |
+| [--as](#-as)                 | Set `asm` assembler                          |
+| [--cc](#-cc)                 | Set `c` compiler                             |
+| [--cxx](#-cxx)               | Set `c++` compiler                           |
+| [--mm](#-mm)                 | Set `objc` compiler                          |
+| [--mxx](#-mxx)               | Set `objc++` compiler                        |
+| [--sc](#-sc)                 | Set `swift` compiler                         |
+| [--gc](#-gc)                 | Set `golang` compiler                        |
+| [--dc](#-dc)                 | Set `dlang` compiler                         |
+| [--rc](#-rc)                 | Set `rust` compiler                          |
+| [--ld](#-ld)                 | Set `c/c++/objc/asm` linker                  |
+| [--sh](#-sh)                 | Set `c/c++/objc/asm` shared library linker   |
+| [--ar](#-ar)                 | Set `c/c++/objc/asm` static library archiver |
+| [--sc-ld](#-sc-ld)           | Set `swift` linker                           |
+| [--sc-sh](#-sc-sh)           | Set `swift` shared library linker            |
+| [--gc-ld](#-gc-ld)           | Set `golang` linker                          |
+| [--gc-ar](#-gc-ar)           | Set `golang` static library archiver         |
+| [--dc-ld](#-dc-ld)           | Set `dlang` linker                           |
+| [--dc-sh](#-dc-sh)           | Set `dlang` shared library linker            |
+| [--dc-ar](#-dc-ar)           | Set `dlang` static library archiver          |
+| [--rc-ld](#-rc-ld)           | Set `rust` linker                            |
+| [--rc-sh](#-rc-sh)           | Set `rust` shared library linker             |
+| [--rc-ar](#-rc-ar)           | Set `rust` static library archiver           |
+| [--asflags](#-asflags)       | Set `asm`汇编 compiler option                |
+| [--cflags](#-cflags)         | Set `c` compiler option                      |
+| [--cxflags](#-cxflags)       | Set `c/c++` compiler option                  |
+| [--cxxflags](#-cxxflags)     | Set `c++` compiler option                    |
+| [--mflags](#-mflags)         | Set `objc` compiler option                   |
+| [--mxflags](#-mxflags)       | Set `objc/c++` compiler option               |
+| [--mxxflags](#-mxxflags)     | Set `objc++` compiler option                 |
+| [--scflags](#-scflags)       | Set `swift` compiler option                  |
+| [--gcflags](#-gcflags)       | Set `golang` compiler option                 |
+| [--dcflags](#-dcflags)       | Set `dlang` compiler option                  |
+| [--rcflags](#-rcflags)       | Set `rust` compiler option                   |
+| [--ldflags](#-ldflags)       | Set  linker option                           |
+| [--shflags](#-shflags)       | Set  shared library linker option            |
+| [--arflags](#-arflags)       | Set  static library archiver option          |
+
 <p class="tip">
-    You can use short or long command option, for exmaple: <br>
-    `xmake f` or `xmake config`.<br>
-    `xmake f -p linux` or `xmake config --plat=linux`.<br>
-    `xmake f -p linux -a i386` or `xmake config --plat=linux --arch=i386`.<br>
-    <br>
-    And if you want to known more options, please run: `xmake f --help`
+if you want to known more options, please run: `xmake f --help`。
 </p>
 
+###### --sdk
+
+- Set the sdk root directory of toolchains
+
+xmake provides a convenient and flexible cross-compiling support.
+In most cases, we need not to configure complex toolchains prefix, for example: `arm-linux-`
+
+As long as this toolchains meet the following directory structure:
+
+```
+/home/toolchains_sdkdir
+   - bin
+       - arm-linux-gcc
+       - arm-linux-ld
+       - ...
+   - lib
+       - libxxx.a
+   - include
+       - xxx.h
+```
+
+Then，we can only configure the sdk directory and build it.
+
+```bash
+$ xmake f -p linux --sdk=/home/toolchains_sdkdir
+$ xmake
+```
+
+xmake will detect the prefix: arm-linux- and add the include and library search directory automatically.
+
+```
+-I/home/toolchains_sdkdir/include -L/home/toolchains_sdkdir/lib
+```
+
+###### --toolchains
+
+- Set the `bin` directory of toolchains
+
+We need set it manually if the toolchains /bin directory is in other places, for example:
+
+```bash
+$ xmake f -p linux --sdk=/home/toolchains_sdkdir --toolchains=/usr/opt/bin
+$ xmake
+```
+
+###### --cross
+
+- Set the prefix of compilation tools
+
+For example, under the same toolchains directory at the same time, there are two different compilers:
+
+```
+/opt/bin
+ - armv7-linux-gcc
+ - aarch64-linux-gcc
+```
+
+If we want to use the `armv7-linux-gcc` compiler, we can run the following command:
+
+```bash
+$ xmake f -p linux --sdk=/usr/toolsdk --toolchains=/opt/bin --cross=armv7-linux-
+```
+
+###### --as
+
+- Set `asm` assembler
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --as=armv7-linux-as
+```
+
+If the 'AS' environment variable exists, it will use the values specified in the current environment variables.
+
+###### --cc
+
+- Set c compiler
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --cc=armv7-linux-clang
+```
+
+If the 'CC' environment variable exists, it will use the values specified in the current environment variables.
+
+###### --cxx
+
+- Set `c++` compiler
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --cxx=armv7-linux-clang++
+```
+
+If the 'CXX' environment variable exists, it will use the values specified in the current environment variables.
+
+###### --ld
+
+- Set `c/c++/objc/asm` linker
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --ld=armv7-linux-clang++
+```
+
+If the 'LD' environment variable exists, it will use the values specified in the current environment variables.
+
+###### --sh
+
+- Set `c/c++/objc/asm` shared library linker
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --sh=armv7-linux-clang++
+```
+
+If the 'SH' environment variable exists, it will use the values specified in the current environment variables.
+
+###### --ar
+
+- Set `c/c++/objc/asm` static library archiver
+
+```bash
+$ xmake f -p linux --sdk=/user/toolsdk --ar=armv7-linux-ar
+```
+
+If the 'AR' environment variable exists, it will use the values specified in the current environment variables.
+
 #### Global Configuration
 
 You can save to the global configuration for simplfying operation.
diff --git a/docs/zh/README.md b/docs/zh/README.md
index 86908ff64..03455e8d3 100755
--- a/docs/zh/README.md
+++ b/docs/zh/README.md
@@ -231,7 +231,7 @@ $ xmake
 | 参数名                       | 描述                             |
 | ---------------------------- | -------------------------------- |
 | [--sdk](#-sdk)               | 设置交叉工具链的sdk根目录        |
-| [--toolchains](#-toolchains) | 设置工具链bin目录录              |
+| [--toolchains](#-toolchains) | 设置工具链bin目录                |
 | [--cross](#-cross)           | 设置交叉工具链工具前缀           |
 | [--as](#-as)                 | 设置`asm`汇编器                  |
 | [--cc](#-cc)                 | 设置`c`编译器                    |