mirror of https://github.com/acidanthera/audk.git
70bd69912a
In GCC 4.7, a feature was added to the ARM backend that allows unaligned loads and stores to be emitted. Since it is enabled by default on ARMv6 and later CPUs, and since such code is not suitable in our case (i.e., bare metal code), we must disable it by passing the -mno-unaligned-access option if we are using GCC 4.7 or later. However, this particular feature and its enabling by default have been backported to version 4.6 by Linaro. Since the Linaro toolchains are widely used for ARM development, and also shipped by distros such as Ubuntu, we should disable the feature on version 4.6 as well. Unfortunately, since the upstream version does not support the feature, it also does not understand the -mno-unaligned-access option. Since GCC sets the builtin #define __ARM_FEATURE_UNALIGNED to 1 when -munaligned-access is in effect, we can force the build to fail in this case by passing -D__ARM_FEATURE_UNALIGNED=0 on the GCC command line. This will produce the following error message: <command-line>:0:0: error: "__ARM_FEATURE_UNALIGNED" redefined [-Werror] <built-in>:0:0: note: this is the location of the previous definition and terminate the build. This patch may cause some existing builds to fail, but they will be builds that were previously at risk of unexpected runtime exceptions. Those builds can also easily be switched to the GCC47 profile instead, generating safe binaries. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18228 6f19259b-4bc3-4df7-8a09-765794883524 |
||
|---|---|---|
| .. | ||
| Bin | ||
| BinWrappers/PosixLike | ||
| Conf | ||
| Scripts | ||
| Source | ||
| Tests | ||
| UserManuals | ||
| gcc | ||
| .gitignore | ||
| BuildEnv | ||
| BuildNotes.txt | ||
| Contributions.txt | ||
| GNUmakefile | ||
| License.txt | ||
| Makefile | ||
| ReadMe.txt | ||
| building-gcc.txt | ||
| get_vsvars.bat | ||
| toolsetup.bat | ||
ReadMe.txt
This directory contains the next generation of EDK II build tools and template files. Templates are located in the Conf directory, while the tools executables for Microsoft Windows 32-bit Operating Systems are located in the Bin\Win32 directory, other directory contatins tools source. 1. Build step to generate the binary tools. === Windows/Visual Studio Notes === To build the BaseTools, you should run the standard vsvars32.bat script. In addition to this, you should set the following environment variables: * EDK_TOOLS_PATH - Path to the BaseTools sub directory under the edk2 tree * BASE_TOOLS_PATH - The directory where the BaseTools source is located. (It is the same directory where this README.txt is located.) * PYTHON_FREEZER_PATH - Path to where the python freezer tool is installed After this, you can run the toolsetup.bat file, which is in the same directory as this file. It should setup the remainder of the environment, and build the tools if necessary. Please also refer to the 'BuildNotes.txt' file for more information on building under Windows. === Unix-like operating systems === To build on Unix-like operating systems, you only need to type 'make' in the base directory of the project. === Ubuntu Notes === On Ubuntu, the following command should install all the necessary build packages to build all the C BaseTools: sudo apt-get install build-essential uuid-dev === Python sqlite3 module === On Windows, the cx_freeze will not copy the sqlite3.dll to the frozen binary directory (the same directory as build.exe and GenFds.exe). Please copy it manually from <PythonHome>\DLLs. The Python distributed with most recent Linux will have sqlite3 module built in. If not, please install sqlit3 package separately. 26-OCT-2011