mirror of
https://github.com/ukui/kernel.git
synced 2026-03-09 10:07:04 -07:00
Nathan Chancellor
fd9d0ca2cc
This was all done to work around a GCC bug that has been fixed after 4.2. The kernel requires GCC 4.6 or newer so remove all of these hacks and just use the traditional flags. $ mips64-linux-gcc --version | head -n1 mips64-linux-gcc (GCC) 4.6.3 $ mips64-linux-gcc -EB -dM -E -C -x c /dev/null | grep MIPSE #define MIPSEB 1 #define __MIPSEB__ 1 #define _MIPSEB 1 #define __MIPSEB 1 $ mips64-linux-gcc -EL -dM -E -C -x c /dev/null | grep MIPSE #define __MIPSEL__ 1 #define MIPSEL 1 #define _MIPSEL 1 #define __MIPSEL 1 This is necessary when converting the MIPS VDSO to use $(LD) instead of $(CC) to link because the OUTPUT_FORMAT is defaulted to little endian and only flips to big endian when '-EB' is set on the command line. There is no issue currently because the compiler explicitly passes '-EB' or '-EL' to the linker regardless of whether or not it was provided by the user. Passing '-v' to VDSO_LDFLAGS shows: <gcc_prefix>/libexec/gcc/mips64-linux/9.3.0/collect2 ... -EB ... even though '-EB' is nowhere to be found in KBUILD_CFLAGS. The VDSO Makefile already supports getting '-EB' or '-EL' from KBUILD_CFLAGS through a filter directive but '-EB' or '-EL' is not always present. If we do not do this, we will see the following error when compiling for big endian: $ make -j$(nproc) ARCH=mips CROSS_COMPILE=mips64-linux- \ 64r2el_defconfig arch/mips/vdso/ ... mips64-linux-ld: arch/mips/vdso/elf.o: compiled for a big endian system and target is little endian mips64-linux-ld: arch/mips/vdso/elf.o: endianness incompatible with that of the selected emulation mips64-linux-ld: failed to merge target specific data of file arch/mips/vdso/elf.o ... Remove this legacy hack and just use '-EB' and '-EL' unconditionally. Reported-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.