The current Buildroot works just well with sysrootable glibc
toolchains, using the external toolchain feature. The only thing that
needs to be customized is the set of libraries that must be compiled
to the target.
The following patch takes a simple approach to making it easier for
users to use glibc toolchains. It just adds a uClibc/glibc choice in
the external toolchain menu. Then, depending on that selection, the
configuration system will choose a sane default value for the library
files list.
The other advantage of having a uClibc/glibc choice is that in the
future, we'll be able to add checks verifying that the external
toolchain configuration matches the features selected in Buildroot (in
terms of IPv6, RPC, locales or large file support).
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
We used to use different gdb configs for internal and external toolchains
because mconf won't source the same file twice. This works, but is kind of
sub optimal, as people forget to keep them in sync.
Fix it to use the same file for both situations by shuffling around the
config options a bit. Should work identical to before (except for the newer
gdb versions available for ext).
External toolchain C++ cross-compiler fix
package/Makefile.in resets CXX to "" in TARGET_CONFIGURE_OPTS if
BR2_GCC_CROSS_CXX is not set to 'y'. However, when using an external
toolchain, BR2_GCC_CROSS_CXX is not set even if the toolchain has a
C++ cross-compiler.
This patch adds a new BR2_GCC_CROSS_CXX option in the external
toolchain configuration menu, so that just like BR2_INET_RPC,
BR2_INET_IPV6 and the others, it can be set according to the external
toolchain configuration.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Improve external toolchain support
* Do not put kernel-headers in the dependencies of BASE_TARGETS in
the case where BR2_TOOLCHAIN_SOURCE is not y. The kernel headers
are already supposed to be part of the external toolchain, so
there's no need to download, extract and install them.
* In the configuration system, don't display the kernel headers
version selection list when an external toolchain is selected. This
is implemented by moving the source
"toolchain/kernel-headers/Config.in" inside the if
BR2_TOOLCHAIN_SOURCE in toolchain/Config.in.2.
* Change the description and help message of the BR2_LARGEFILE,
BR2_INET_IPV6, BR2_INET_RPC, and BR2_SOFT_FLOAT option in
toolchain/external-toolchain/Config.in. In the case of an external
toolchain, the semantic of these options is not to enable large
file support, IPV6 or RPC (since the toolchain is already compiled,
it has been decided previously). Their semantic is to let Buildroot
know about the characteristics of the external toolchain being
used.
As an improvement, we could guess these values automatically:
- for BR2_LARGEFILE, look at the value of __UCLIBC_HAS_LFS__ in
bits/uClibc_config.h in the libc headers directory.
- for BR2_INET_RPC, look at the value of __UCLIBC_HAS_RPC__ in the
same file
- for BR2_INET_IPV6, look at the value of __UCLIBC_HAS_IPV6__ in
the same file
- for BR2_SOFT_FLOAT, look at the output of $(CC) -v 2>&1 | grep
-- "--with-float=soft"
But I'm not sure how this would be possible, since these values are
used at configuration-time by other configuration options, not only
at build time.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
