Now that all SuperH cores have an MMU, and must use it, move back the
select BR2_ARCH_HAS_MMU_MANDATORY one level up.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Until commit "arch/Config.in.sh: fixup MMU selection" in this series,
SH2A could either be used with BR2_USE_MMU disabled or BR2_USE_MMU
enabled.
The later made absolutely no sense, since SH2A does not have a MMU:
MMU support was introduced starting from SH3 according to
https://en.wikipedia.org/wiki/SuperH#SH-3
Also, since commit 22d5501e03 ("arch:
tidy up binary formats config"), which was merged in Buildroot
2015.05, the architecture tuple used when BR2_sh2a=y and BR2_USE_MMU
disabled is sh2a-buildroot-uclinux-uclibc, and this was already
unsupported back in the days of Buildroot 2015.08 and binutils 2.24,
causing the build to fail with:
*** BFD does not support target sh2a-buildroot-uclinux-uclibc.
just like it fails to build today with recent version of binutils.
So, this has been broken since 2015.08, and nobody complained. SH2A is
seldom used, so it's time to kill it.
It is worth mentioning that there had been an attempt at resurrecting
SH2 support around 2015 (see https://lwn.net/Articles/647636/) as part
of the J2 core. This effort led to the addition of FDPIC support for
SH2A in the musl C library (and therefore proper ELF binaries, with
shared libraries), but that was never supported in Buildroot. Now that
the J2 project is essentially dead, there is no reason to bother with
this.
Fixes:
http://autobuild.buildroot.net/results/63d01d33ae30f86b63b9f42a9fea116f2f3e9005/
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
BR2_sh selects BR2_ARCH_HAS_MMU_OPTIONAL, which means that it's up to
the user to decide whether he wants to use MMU or not on SuperH
platforms.
However:
- On SH2A, there is no MMU at all, so being to select "Use MMU"
doesn't make any sense.
- On SH4, there is no support for *not* using the MMU, so disabling
"Use MMU" will cause the build to fail.
In order to fix this, we move the MMU selection to arch/Config.in.sh:
- BR2_sh2a selects nothing, so that it's always noMMU
- BR2_sh4* select BR2_ARCH_HAS_MMU_MANDATORY so that the MMU is
always used.
Fixes:
http://autobuild.buildroot.net/results/f4d52cabee61ee0f234b03c1ec1bd02e85e7bb20/ (FLAT
selected with sh4aeb)
http://autobuild.buildroot.net/results/d1b1dfe449f82944bd48215da3cdffd05797e2e9/ (FLAT
selected with sh4a)
http://autobuild.buildroot.net/results/45bc90fd2dde7bb201d7f999db1a8024cf889a06/ (FLAT
selected with sh4)
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
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>
... to follow the convention: type, default, depends on, select, help.
Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
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>
It's been deprecated for quite some time now.
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
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>
This patch removes the sh2, sh3 and sh3eb support, because the user
base is inexistent, and the Linux support for these architectures is
poor. The sh2a support is preserved, because at least one user
expressed interest in this architecture, and is actually using it:
http://lists.busybox.net/pipermail/buildroot/2013-April/070399.html
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Probably due to some copy/paste mistake, Config.in.sh was defining
BR2_ENDIAN to "LITTLE" when the architecture is BR2_x86_64. Due to the
fact that Config.in.sh is never included when we are building for
x86_64, this is a no-op, but is certainly good to clean up.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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>
target/Config.in.arch had become too long, and we want to remove the
target/ directory. So let's move it to arch/ and split it this way:
* An initial Config.in that lists the top-level architecture, and
sources the arch-specific Config.in.<arch> files, as well as
Config.in.common (see below)
* One Config.in.<arch> per architecture, listing the CPU families,
ABI choices, etc.
* One Config.in.common that defines the gcc mtune, march, mcpu values
and other hidden options.
[Peter: space->tab fix, mipsel64 little endian, mips3 as noted by Arnout]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
