Christer Solskogen kirjoitti 23.9.2018 klo 0.56:
On 9/22/2018 10:23 PM, Juan Pablo Garibotti Arias wrote:
I'm trying to build a cross compiler for UEFI, and having difficulties
building libgcc after having built the compilers themselves. I've
already
built a cross compiler and libgcc (with and without red-zone) for
freestanding x86_64-elf in the same machine, so not sure what the
issue is.
The source for gcc was downloaded to ~/src/gcc. After that, I did:
export PREFIX="$HOME/opt/cross"
export TARGET=x86_64-w64-mingw32
export PATH="$PREFIX/bin:$PATH"
mkdir ~/src/gcc-build-$TARGET
cd ~/src/gcc-build-$TARGET
../gcc/configure --target=$TARGET --prefix="$PREFIX" --disable-nls
--enable-languages=c,c++ --without-headers
The build order I use is something like this:
binutils
gcc (all-gcc && install-gcc)
mingw-headers
mingw-crt
full gcc
With an already existing target which has an already built and tested
target C libraries
like 'x86_64-w64-mingw32' and 'x86_64-redhat-linux' (CentOS, Fedora) it
is quite vain
and even questionable (will the result really be the same?) to try to
rebuild this already
existing target C library stuff. One could ask oneself whether one
really would rebuild
the target C library stuff in the native GCC case. If not, why on earth
in the cross GCC
case? (A resurrection of the native GCC for the target on another host
with only new
executables for the new cross host)
So just choosing a SYSROOT to keep the already existing target stuff (in
this case as
downloaded mingw-packages from the MinGW site) and using the
'--with-sysroot=$SYSROOT'
to point to them when configuring GNU binutils and GCC, would be the
recommendation
from me. If one chooses PREFIX="$HOME/opt/cross" (for keeping all the
crosstools) then
a quite obvious choose for the TARGET stuff would be to use
SYSROOT=$PREFIX/host-$TARGET,
in this case it would lead using
'$HOME/opt/cross/host-x86_64-w64-mingw32' as the SYSROOT
for the MinGW stuff. When making more crosstoolchains one then uses
the same standard,
for instance with a crosstoolchain for 'x86_64-centos7-linux' one would
use the
'$HOME/opt/cross/host-x86_64-centos7-linux' as the SYSROOT for the
CentOS7 stuff and
the '$HOME/opt/cross/bin' for the 'x86_64-centos7-linux-*' named
executables.
With the "embedded targets" like 'x86_64-elf' one doesn't use any
SYSROOT because there
aren't any "existing target standard C libraries" but one usually
compiles them from the newlib
sources at the same time with the GCC sources. The resulting standard C
libraries will go into
the default '$PREFIX/$TARGET/include' and '$PREFIX/$TARGET/lib', in the
previous "standard"
into the '$HOME/opt/cross/x86_64-elf/include' and
'$HOME/opt/cross/x86_64-elf/lib' in the
'x86_64-elf' target case. Whether newlib now supports the 'x86_64-elf'
target I have no clue,
the 'i386-elf' has been there from the very beginning and I remember
toying with it to make
a crosscompiler which could make simple executables for both DJGPP2 on
MS-DOS and Unix
SVR4.2 (UnixWare and Linux with ibcs2).
