Currently, the ARM Config.in logic specifies values for
--with-arch/-march and --with-tune/-mtune, but not for
--with-cpu/-mcpu. However, this causes problems on ARMv4, because
specifying --with-arch=armv4t isn't enough to make gcc generate ARMv4
code: one should also pass --with-cpu=<some ARMv4 CPU>.
Moreover, since Buildroot is generally designed to generate code
specifically for the configured target, it makes sense to give our own
--with-cpu/-mcpu value instead of relying on the default value used by
gcc, and only do small optimizations with -mtune.
Reported-by: Adam Hussein <kryme76@yahoo.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Commit 6b3a0417c4 ('arch/arm: arm926 may have VFP') forgot to update
the help text of the VFPv2 option to mention ARMv5. This commit fixes
that.
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>
Until now, we were using the default ARM instruction set, as used by
the toolchain: the 32 bits ARM instruction set for the internal
backend, and for external toolchain, whatever default was chosen when
the toolchain was generated.
This commit adds support for the Thumb2 instruction set. To do so, it:
* provides a menuconfig choice between ARM and Thumb2. The choice is
only shown when Thumb2 is supported, i.e on ARMv7-A CPUs.
* passes the --with-mode={arm,thumb} option when building gcc in the
internal backend. This tells the compiler which type of
instructions it should generate.
* passes the m{arm,thumb} option in the external toolchain
wrapper. ARM and Thumb2 code can freely be mixed together, so the
fact that the C library has been built either ARM or Thumb2 and
that the rest of the code is built Thumb2 or ARM is not a problem.
[Peter: fix empty BR2_GCC_TARGET_MODE check]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
This commit introduces the support for the EABIhf ABI, next to the
existing support we have for EABI and OABI (even though OABI support
is deprecated). EABIhf allows to improve performance of floating point
workload by using floating point registers to transfer floating point
arguments when calling functions, instead of using integer registers
to do, as is done in the 'softfp' floating point model of EABI.
In addition to this, this commit introduces a list of options for the
floating point support:
* Software floating point
* VFP
* VFPv3
* VFPv3-D16
* VFPv4
* VFPv4-D16
and it introduces some logic to make sure the options are only visible
when it makes sense, depending on the ARM core being selected. This is
however made complicated by the fact that certain VFP capabilities are
mandatory on some cores, but optional on some other cores. The kconfig
logic tries to achieve the following goals:
* Hide options that are definitely not possible.
* Use safe default values (i.e for Cortex-A5 and A7, the presence of
the VFPv4 unit is optional, so we default on software floating
point on these cores)..
* Show the available possibilities, even if some of them are not
necessarily working on a particular core (again, for the Cortex-A5
and A7 cores, there is no way of knowing whether the particular
variant used by the user has VFPv4 or not, so we select software
floating point by default, but still show VFP/VFPv3/VFPv4 options).
It is worth noting that this commit doesn't add support for all
possible -mfpu= values on ARM. We haven't added support for fpa, fpe2,
fpe3, maverick (those four are only used on very old ARM cores), for
vfpv3-fp16, vfpv3-d16-fp16, vfpv3xd, vfpv3xd-fp16, neon-fp16,
vfpv4-sp-d16. They can be added quite easily if needed thanks to the
new organization of the Config.in options.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
As we are going to introduced a more advanced support of floating
point options for the ARM architecture, we need to adjust how the
soft-float option is handled. We replace the current hidden option
BR2_PREFER_SOFT_FLOAT option and the visible BR2_SOFT_FLOAT option by:
* A global hidden BR2_SOFT_FLOAT option, defined in arch/Config.in,
that tells whether the architecture-specific code is using software
emulated floating point. This hidden option can be used throughout
Buildroot to determine whether soft float is used or not.
* Per-architecture visible BR2_<arch>_SOFT_FLOAT options, for the
architecture for which it makes sense, which allows users to select
soft float emulation when needed.
This change will allow each architecture to have a different way of
presenting its floating point capabilities.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
OABI is more than legacy, it's dead.
New developments should go with EABI, since it so much better.
>From the Debian EABI page [0] :
- floating point performance, with or without an FPU is very much faster
- mixing soft and hardfloat code is possible
- structure packing is not as painful as it used to be
- a more efficient syscall convention
- more compatibility with various tools
[0] http://wiki.debian.org/ArmEabiPort
[Thomas: keep the ABI choice, as we are going to introduce EABIhf later].
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
* Add Faraday FA526/626 as suggested on bug #1291
Note however that these cores are v4 and NOT v4t.
* Make the sa110 & sa1110 cores -> strongarm since they're the same.
* Drop all of the ARM variants lower than v4 including generic, there's
no point in supporting obsolete targets.
* Fix uClibc USE_BX logic, it was always on, this would break the new
FA526/626 support and broke StrongARM since it's a v4 core.
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Kconfig does not accepts that a symbol that is part of a choice
be affected a default value.
Fix this by introducing a dummy EABI symbol, and make the real
EABI symbol a prompt-less option that depends on !OABI.
[Peter: drop arm dependency, rename to EABI_CHOICE]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
The BR2_ARM_EABI config symbol is still kept in order to minimize
the impact.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
According to the ARM1136JF-S and ARM1136J-S Revision r1p5 Technical Reference
Manual, from release rev1 (r1pn), the ARM1136JF-S processor implements the ARMv6
instruction set with the ARMv6k additions.
This patch differentiates the ARM1136JF-S revisions 0 and 1 in order to use
either ARMv6j (e.g. on Freescale i.MX31) or ARMv6k (e.g. on Freescale i.MX35).
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Update the arm processor types: add the cortex A5 & A15 variants.
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Suggested by Yann E. Morin.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reported-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
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>
