buildroot/arch
Thomas De Schampheleire dd8a410eaf core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH
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>
2022-02-08 21:20:23 +01:00
..
arch.mk arch: drop BR2_GCC_TARGET_CPU_REVISION option 2018-10-01 14:52:32 +02:00
arch.mk.arc arch/arc: explicitly set "max-page-size" for GNU LD 2019-12-25 22:09:52 +01:00
arch.mk.csky arch/csky: add support for the ck860 core 2019-05-31 22:59:57 +02:00
arch.mk.riscv arch: add support for RISC-V 32-bit (riscv32) architecture 2019-01-06 14:09:31 +01:00
arch.mk.xtensa arc/xtensa: store the Xtensa overlay in the per-package DL_DIR 2018-04-02 15:59:30 +02:00
Config.in core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.arc core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.arm core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.csky core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.m68k core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.microblaze core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.mips core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.nds32 core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.nios2 core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.or1k core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.powerpc core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.riscv core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.s390x core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.sh core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.sparc core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.x86 core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00
Config.in.xtensa core: introduce NORMALIZED_ARCH as non-kernel replacement for KERNEL_ARCH 2022-02-08 21:20:23 +01:00