+Only the MdePkg and EdkModulePkg are currently supported by gcc builds. Other\r
+builds, such as the EdkNt32Pkg, will not compile with gcc. By default, the edk2\r
+will try to build the NT32.fpd, which is not supported by gcc. So, you need to\r
+change the Tools/Conf/target.txt.\r
+\r
+The platform to be built is identified by the Tools/Conf/target.txt file:\r
+\r
+#\r
+# PROPERTY Type Use Description\r
+# ---------------- -------- -------- -----------------------------------------------------------\r
+# ACTIVE_PLATFORM Filename Recommended Specify the WORKSPACE relative Path and Filename \r
+# of the platform FPD file that will be used for the build\r
+# This line is required if and only if the current working\r
+# directory does not contain one or more FPD files.\r
+\r
+ACTIVE_PLATFORM =\r
+ \r
+You can leave it black, as above, or set it to any .fpd file in the workspace.\r
+If you leave it blank, then you just cd to the dir that contains the .fpd that\r
+you would like to build (MdePkg/ or EdkModulePkg/) and then type build.\r
+\r
+----------------------------\r
+A Word on compiling on Linux\r
+----------------------------\r
+\r
+In order to compile on Linux, you will need to have the e2fsprogs-dev package\r
+installed. Check your distribution for the rpm, deb or other package format.\r
+This package contains the uuid library and header that are used by some of the\r
+host tools.\r
+\r
+If you are running on x86_64 Linux, then you should install a 64 bit version of\r
+the Java JDK. The version that was used was jdk-1_5_0_07-linux-amd64-rpm.bin.\r
+It may be downloaded from sun.com.\r
+\r
+-----------------------------------------\r
+A Word on compiling under Cygwin with gcc\r
+-----------------------------------------\r
+\r
+Cygwin is a POSIX style operating environment for Windows. It is possible to\r
+compile the EDK 2 using gcc and cygwin. Compiling under cygwin is slow, because \r
+the underlying file accesses are slow in cygwin. For this reason, we do not \r
+encourage the use of cygwin. A true unix system will be a superior choice for \r
+those wishing to compile with gcc.\r
+\r
+Make sure that you select the e2fsprogs development package when you install\r
+cygwin. It is necessary for the GenFvImage tool.\r
+\r
+----------------------------------------\r
+A Word on gcc for Processor Architectures\r
+----------------------------------------\r
+\r
+Currently gcc support is limited to IA-32 builds, generating IA-32 PE32 images. \r
+\r
+The X64 bit (Intel 64, etc.) support under the gcc compiler does not support the EFIAPI \r
+calling convention (as defined in the UEFI 2.0 specification Chapter 2), so it is not \r
+possible to build a working EFI image for an X64 environment. Since the x64 gcc does \r
+not support the EFIAPI calling convention the x64 tools do not support generating a \r
+PE32+ image. The EFIAPI calling convention is very similar to the Microsoft x64 \r
+calling convention.\r
+\r
+On ItaniumĀ® Processors the gcc compiler does not support generating a PE32+ image.\r