Update description related to ARM rootfs (#8962)

Update description in script and documentation related to ARM rootfs.

1. Change arm-softfp to armel to apply recent changes.

2. Change UbuntuCodeName to LinuxCodeName
For arm and armel, rootfs are available from three different Linux distro.
    For arm, Ubuntu is available.
    For armel, Debian and Tizen are available.

Signed-off-by: Hyung-Kyu Choi <hk0110.choi@samsung.com>

2 files changed, 34 insertions, 21 deletions

diff --git a/Documentation/building/cross-building.md b/Documentation/building/cross-building.md
index ab5897a24a..30c7aca741 100644
--- a/Documentation/building/cross-building.md
+++ b/Documentation/building/cross-building.md
@@ -21,11 +21,12 @@ and conversely for arm64:
 
 Generating the rootfs
 ---------------------
-The `cross\build-rootfs.sh` script can be used to download the files needed for cross compilation. It will generate an Ubuntu 14.04 rootfs as this is what CoreCLR targets.
+The `cross\build-rootfs.sh` script can be used to download the files needed for cross compilation. It will generate an rootfs as this is what CoreCLR targets.
 
-    Usage: build-rootfs.sh [BuildArch] [UbuntuCodeName]
-    BuildArch can be: arm, arm-softfp, arm64
-    UbuntuCodeName - optional, Code name for Ubuntu, can be: trusty(default), vivid, wily
+    Usage: ./cross/build-rootfs.sh [BuildArch] [LinuxCodeName] [lldbx.y] [--skipunmount]
+    BuildArch can be: arm(default), armel, arm64, x86
+    LinuxCodeName - optional, Code name for Linux, can be: trusty(default), vivid, wily, xenial. If BuildArch is armel, LinuxCodeName is jessie(default) or tizen.
+    lldbx.y - optional, LLDB version, can be: lldb3.6(default), lldb3.8
 
 The `build-rootfs.sh` script must be run as root as it has to make some symlinks to the system, it will by default generate the rootfs in `cross\rootfs\<BuildArch>` however this can be changed by setting the `ROOTFS_DIR` environment variable.
 
@@ -33,7 +34,7 @@ For example, to generate an arm rootfs:
 
     ben@ubuntu ~/git/coreclr/ $ sudo ./cross/build-rootfs.sh arm
 
-You can choose Ubuntu code name to match your target, give `vivid` for `15.04`, `wily` for `15.10`. Default is `trusty`, version `14.04`.
+You can choose Linux code name to match your target, give `vivid` for `Ubuntu 15.04`, `wily` for `Ubuntu 15.10`. Default is `trusty`, version `Ubuntu 14.04`.
 
     ben@ubuntu ~/git/coreclr/ $ sudo ./cross/build-rootfs.sh arm wily
 
@@ -41,6 +42,18 @@ and if you wanted to generate the rootfs elsewhere:
 
     ben@ubuntu ~/git/coreclr/ $ sudo ROOTFS_DIR=/home/ben/coreclr-cross/arm ./cross/build-rootfs.sh arm
 
+For example, to generate an armel rootfs:
+
+    hqu@ubuntu ~/git/coreclr/ $ sudo ./cross/build-rootfs.sh armel
+
+You can choose code name to match your target, give `jessie` for `Debian`, `tizen` for `Tizen`. Default is `jessie`.
+
+    hque@ubuntu ~/git/coreclr/ $ sudo ./cross/build-rootfs.sh armel tizen
+
+and if you wanted to generate the rootfs elsewhere:
+
+    hque@ubuntu ~/git/coreclr/ $ sudo ROOTFS_DIR=/home/ben/coreclr-cross/armel ./cross/build-rootfs.sh armel tizen
+
 
 Cross compiling CoreCLR
 -----------------------
@@ -117,7 +130,7 @@ prajwal@ubuntu ~/coreclr $ ./tests/scripts/arm32_ci_script.sh \
     --skipTests
 ```
 
-The Linux ARM Emulator is based on soft floating point and thus the native binaries in coreclr are built for the arm-softfp architecture. The coreclr binaries generated by the above command (native and mscorlib) can be found at `~/coreclr/bin/Product/Linux.arm-softfp.Release`.
+The Linux ARM Emulator is based on soft floating point and thus the native binaries in coreclr are built for the armel architecture. The coreclr binaries generated by the above command (native and mscorlib) can be found at `~/coreclr/bin/Product/Linux.armel.Release`.
 
 To build libcoreclr and mscorlib, and run selected coreclr unit tests on the emulator, do the following:
 * Download the latest Coreclr unit test binaries (or build on Windows) from here: [Debug](http://dotnet-ci.cloudapp.net/job/dotnet_coreclr/job/master/job/debug_windows_nt_bld/lastSuccessfulBuild/artifact/bin/tests/tests.zip) and [Release](http://dotnet-ci.cloudapp.net/job/dotnet_coreclr/job/master/job/release_windows_nt_bld/lastSuccessfulBuild/artifact/bin/tests/tests.zip).  
diff --git a/cross/build-rootfs.sh b/cross/build-rootfs.sh
index aa154f7b2b..72ccc569a0 100755
--- a/cross/build-rootfs.sh
+++ b/cross/build-rootfs.sh
@@ -2,16 +2,16 @@
 
 usage()
 {
-    echo "Usage: $0 [BuildArch] [UbuntuCodeName] [lldbx.y] [--skipunmount]"
+    echo "Usage: $0 [BuildArch] [LinuxCodeName] [lldbx.y] [--skipunmount]"
     echo "BuildArch can be: arm(default), armel, arm64, x86"
-    echo "UbuntuCodeName - optional, Code name for Ubuntu, can be: trusty(default), vivid, wily, xenial. If BuildArch is armel, UbuntuCodeName is jessie(default) or tizen."
+    echo "LinuxCodeName - optional, Code name for Linux, can be: trusty(default), vivid, wily, xenial. If BuildArch is armel, LinuxCodeName is jessie(default) or tizen."
     echo "lldbx.y - optional, LLDB version, can be: lldb3.6(default), lldb3.8"
     echo "--skipunmount - optional, will skip the unmount of rootfs folder."
 
     exit 1
 }
 
-__UbuntuCodeName=trusty
+__LinuxCodeName=trusty
 
 __CrossDir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 __InitialDir=$PWD
@@ -43,7 +43,7 @@ for i in "$@"
             __BuildArch=armel
             __UbuntuArch=armel
             __UbuntuRepo="http://ftp.debian.org/debian/"
-            __UbuntuCodeName=jessie
+            __LinuxCodeName=jessie
             ;;
         x86)
             __BuildArch=x86
@@ -57,22 +57,22 @@ for i in "$@"
             __LLDB_Package="lldb-3.8-dev"
             ;;
         vivid)
-            if [ "$__UbuntuCodeName" != "jessie" ]; then
-                __UbuntuCodeName=vivid
+            if [ "$__LinuxCodeName" != "jessie" ]; then
+                __LinuxCodeName=vivid
             fi
             ;;
         wily)
-            if [ "$__UbuntuCodeName" != "jessie" ]; then
-                __UbuntuCodeName=wily
+            if [ "$__LinuxCodeName" != "jessie" ]; then
+                __LinuxCodeName=wily
             fi
             ;;
         xenial)
-            if [ "$__UbuntuCodeName" != "jessie" ]; then
-                __UbuntuCodeName=xenial
+            if [ "$__LinuxCodeName" != "jessie" ]; then
+                __LinuxCodeName=xenial
             fi
             ;;
         jessie)
-            __UbuntuCodeName=jessie
+            __LinuxCodeName=jessie
             __UbuntuRepo="http://ftp.debian.org/debian/"
             ;;
         tizen)
@@ -81,7 +81,7 @@ for i in "$@"
                 usage;
                 exit 1;
             fi
-            __UbuntuCodeName=
+            __LinuxCodeName=
             __UbuntuRepo=
             __Tizen=tizen
             ;;
@@ -112,9 +112,9 @@ if [ -d "$__RootfsDir" ]; then
     rm -rf $__RootfsDir
 fi
 
-if [[ -n $__UbuntuCodeName ]]; then
-    qemu-debootstrap --arch $__UbuntuArch $__UbuntuCodeName $__RootfsDir $__UbuntuRepo
-    cp $__CrossDir/$__BuildArch/sources.list.$__UbuntuCodeName $__RootfsDir/etc/apt/sources.list
+if [[ -n $__LinuxCodeName ]]; then
+    qemu-debootstrap --arch $__UbuntuArch $__LinuxCodeName $__RootfsDir $__UbuntuRepo
+    cp $__CrossDir/$__BuildArch/sources.list.$__LinuxCodeName $__RootfsDir/etc/apt/sources.list
     chroot $__RootfsDir apt-get update
     chroot $__RootfsDir apt-get -f -y install
     chroot $__RootfsDir apt-get -y install $__UbuntuPackages