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Fix inadvertent branch
author | William Astle <lost@l-w.ca> |
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date | Wed, 14 Oct 2015 19:15:41 -0600 |
parents | d0c0fede5021 |
children | c8ae69cdb5a9 |
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These files are extra utility type scripts that can be used for various purposes. as This is a sort of front-end script that makes lwasm look approximately like gnu as which is useful for using lwasm as a backend to gcc. You may need to edit it to make it work fully. ld Similar to the "as" script above except for lwlink. ar Similar to the "as" script above except for lwar. gcc6809lw-*.patch These are patches to the main gcc source distribution for specific releases. The last number after the dash is a patch level for the specific patch. It is worth noting that a patch for a particular minor version of GCC may work with later minor versions in the same release sequence. That is, a patch for 4.6.1 might work with 4.6.4. These are different to the official gcc6809 releases in the following ways. First, all the source for as-6809 is removed. Also, the special "helper" makefile and directory is removed. Also, as of this writing, the latest "official" release was for gcc 4.3.4 which does not build on 64 bit linux. In the event you have used the "official" gcc6809 with the default as6809 assembler that comes with it, you should be aware that while lwasm is mostly compatible with it syntax wise, there are differences, particularly in pseudo operations and source line syntax (most notably that you must have whitespace preceeding assembler directives and instructions). You will likely not run into these unless you are using inline asm. Refer to the lwtools documentation for the specific line format required by lwasm. It is worth noting that neither gcc6809 nor lwtools comes with a standard C library. It is also worth noting that for many projects, it will be more flexible to invoke lwlink directly rather than using the ld script or gcc as a front end. See the lwtools documentation for details on using lwlink. To use these scripts, you really need to understand how to build a gcc as a cross compiler. The basics are that you put the as, ld, and ar scripts whereever you plan to put your cross-development binaries. Then, when building the cross compiler, you tell it where the scripts are. Please note that the following recipe is an example only. If you are planning to install multiple instances of gcc6809 for different targets, you will most certainly need to modify the steps below. Providing a complete understanding of building a gcc toolchain for cross compilation is well beyond the scope of this document. The following works for a single installation. 1. Install the ar, as, and ld scripts named m6809-unknown-{as,ar,ld} in a directory in your path, say /usr/local/coco/bin/. 2. Make symbolic links to /bin/true for similarly named nm, objdump, ranlib, and strip in the same directory Some of these may not be necessary. 3. Unpack gcc and apply the gcc6809 patch. The gcc6809lw* patch file in this directory is known to work with these instructions. 4. Make sure /usr/local/coco/bin is in your PATH 5. Make sure "." is NOT in your path or is at the END of PATH. If you have gazillions of errors pop up compiling "gemodes.c", this is your problem. 6. In a directory (other than the gcc source, say "gcc-build" at the same level as the main gcc directory, do (assuming gcc 4.3.4): configure --enable-languages=c --target=m6809-unknown \ --program-prefix=m6809-unknown- --enable-obsolete \ --srcdir=../gcc-4.3.4 --disable-threads --disable-nls \ --disable-libssp --prefix=/usr/local/coco \ --with-as=/usr/local/coco/bin/m6809-unknown-as \ --with-ld=/usr/local/coco/bin/m6809-unknown-ld \ --with-ar=/usr/local/coco/bin/m6809-unknown-ar NOTE: the last three are required to prevent selection of the wrong binutils programs at runtime. --with-sysroot might be useful if you have a C library involved. 7. Run "make". If errors appear, troubleshoot. 8. Run "make install". Note that you will have to have your PATH variable for "root" set up correctly if your install prefix requires root privileges. The above is WOMM certified. YMMV. NOTES ABOUT SPECIFIC PATCHES ============================ gcc6809lw-4.6.4-2.patch This patch essentially disables the "soft registers". These were causing problems leading to compiler crashes. Removing the "t" constraint from the instruction patterns allowed various issues to go away. It is not clear if the original reasoning behind these soft registers is even valid any more. Also fixes a clearly incorrect comparision when determining if a constant fits in 16 bits. For clarity, both the 8 bit and 16 bit comparisons are replaced with straight forward range comparisons rather than the excessively clever scheme that was present before.