The variable 'KERNEL_ARCH' is actually a normalized version of
'ARCH'/'BR2_ARCH'. For example, 'arcle' and 'arceb' both become 'arc', just
as all powerpc variants become 'powerpc'.
It is presumably called 'KERNEL_ARCH' because the Linux kernel is typically
the first place where support for a new architecture is added, and thus is
the entity that defines the normalized name.
However, the term 'KERNEL_ARCH' can also be interpreted as 'the architecture
used by the kernel', which need not be exactly the same as 'the normalized
name for a certain arch'. In particular, for cases where a 64-bit
architecture is running a 64-bit kernel but 32-bit userspace. Examples
include:
* aarch64 architecture, with aarch64 kernel and 32-bit (ARM) userspace
* x86_64 architecture, with x86_64 kernel and 32-bit (i386) userspace
In such cases, the 'architecture used by the kernel' needs to refer to the
64-bit name (aarch64, x86_64), whereas all userspace applications need to
refer the, potentially normalized, 32-bit name.
This means that there need to be two different variables:
KERNEL_ARCH: the architecture used by the kernel
NORMALIZED_ARCH: the normalized name for the current userspace architecture
At this moment, both will actually have the same content. But a subsequent
patch will add basic support for situations described above, in which
KERNEL_ARCH may become overwritten to the 64-bit architecture, while
NORMALIZED_ARCH needs to remain the same (32-bit) case.
This commit replaces use of KERNEL_ARCH where actually the userspace arch is
needed. Places that use KERNEL_ARCH in combination with building of kernel
modules are not touched.
There may be cases where a package builds both a kernel module as userspace,
in which case it may need to know about both KERNEL_ARCH and
NORMALIZED_ARCH, for the case where they differ. But this is to be fixed on
a per-need basis.
Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Reviewed-by: Romain Naour <romain.naour@gmail.com>
[Arnout: Also rename BR2_KERNEL_ARCH to BR2_NORMALIZED_ARCH]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Similar to other arch-specific strings, the 'KERNEL_ARCH' variable can be
determined from Config.in.<arch> files.
Besides aligning with similar strings, this also means simplification: the
big 'sed' covers several architectures not even supported by Buildroot.
Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Reviewed-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
It is too sad when an editor picks up the wrong syntax...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
This config option corresponds to the string returned by readelf for
the "Machine" field of the ELF header. It will be used to check if the
architecture of binaries built by Buildroot match the target
architecture.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Now that BR2_ARCH_HAS_ATOMICS is no longer used anywhere, we can
remove it from arch/Config.in*, as well as from the documentation.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Buildroot toolchain creates big endian binaries instead of little endian
ones for microblaze architecture. The reason is wrong BR2_ARCH string.
KERNEL_ARCH must contain microblaze in both cases.
Signed-off-by: Jan Drazil <xdrazi00@stud.fit.vutbr.cz>
Signed-off-by: Jan Viktorin <xvikto03@stud.fit.vutbr.cz>
Acked-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Tested-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
As suggested by Yann E. Morin, there is a better way than our current
big Config.in.common to define the gcc mtune, mcpu, march,
etc. values. We can split the setting of those values in each
architecture file, which makes a lot more sense.
Therefore, the Config.in file now creates empty kconfig variables
BR2_ARCH, BR2_ENDIAN, BR2_GCC_TARGET_TUNE, BR2_GCC_TARGET_ARCH,
BR2_GCC_TARGET_ABI and BR2_GCC_TARGET_CPU. The values of those
variables are set by the individual Config.in.<arch> files. This is
possible because such files are now only conditionally included
depending on the top-level architecture that has been selected.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
