This targets the existing ARMv6 and ARMv7 SoCs that contain a VFP unit.
This is an optional coprocessors may not be present in all devices, however
it appears to be in all current SoCs we support.
armv6hf targets the VFP variant of the ARM EABI and our copy of gcc is too
old to support this. Because of this there are a number of WITH/WITHOUT
options that are unsupported and must be left as the default value. The
options and their required value are:
* WITH_ARM_EABI
* WITHOUT_GCC
* WITHOUT_GNUCXX
In addition, without an external toolchain, the following need to be left
as their default:
* WITH_CLANG
* WITH_CLANG_IS_CC
As there is a different method of passing float and double values to
functions the ABI is incompatible with existing armv6 binaries. To use
this a full rebuild of world is required. Because no floating point values
are passed into the kernel an armv6 kernel with VFP enabled will work with
an armv6hf userland and vice versa.
are only used on armv6 when the vfp unit is detected. They will also be
available for the upcoming armv6hf platform, however while not used by
default there will need to be defined for any software that calls them
directly.
if not already defined. This allows building libc from outside of
lib/libc using a reach-over makefile.
A typical use-case is to build a standard ILP32 version and a COMPAT32
version in a single iteration by building the COMPAT32 version using a
reach-over makefile.
Obtained from: Juniper Networks, Inc.
Store/restore the VFP registers in setjmp/longjmp on ARM EABI if VFP is
enabled in the kernel. It checks the hw.floatingpoint sysctl to see if
floating-point is available and uses this to determine if it should store
them. If it does it uses a different magic value so longjmp is able to know
if it should load them.
with merge the functions but leave out the code to save/load the VFP
registers as that requires other changes to ensure the VFP is enabled
first.
This removes storing the old fpa registers. These were never fully
supported, and the only user of this code I can find have moved to newer
CPUs which use a VFP.
check_deferred_signal() returns twice, since handle_signal() emulates
the return from the normal signal handler by sigreturn(2)ing the
passed context. Second return is performed on the destroyed stack
frame, because __fillcontextx() has already returned. This causes
undefined and bad behaviour, usually the victim thread gets SIGSEGV.
Avoid nested frame and the need to return from it by doing direct call
to getcontext() in the check_deferred_signal() and using a new private
libc helper __fillcontextx2() to complement the context with the
extended CPU state if the deferred signal is still present.
The __fillcontextx() is now unused, but is kept to allow older
libthr.so to be used with the new libc.
Mark __fillcontextx() as returning twice [1].
Reported by: pgj
Pointy hat to: kib
Discussed with: dim
Tested by: pgj, dim
Suggested by: jilles [1]
MFC after: 1 week
this is not a problem as they are resolved by libgcc. The exception is for
the __aeabi_mem* functions. These call back into libc to the appropriate
function. This causes issues for static binaries as we only link against
libc once so there is no way for it to call into libgcc and back.
The fix for this is to include these symbols in libc but keep them hidden
so binaries use the libgcc version.
but use normal references instead of weak. This makes the statically
linked binaries to use fast gettimeofday(2) by forcing the linker to
resolve references and providing the neccessary functions.
Reported by: bde
Tested by: marius (sparc64)
MFC after: 2 weeks
in r7 and use ip to store the old version of r7 as it is not guaranteed to
be kept when calling a subroutine. The kernel will preserve the register
across system calls.
fit into existing mcontext_t.
On i386 and amd64 do return the extended FPU states using
getcontextx(3). For other architectures, getcontextx(3) returns the
same information as getcontext(2).
Tested by: pho
MFC after: 1 month
the function bodies require only 2 to 10 instructions. However, it
leads to application binaries that refer to a private ABI, namely, the
softfloat innards in libc. This could complicate future changes in
the implementation of the floating-point emulation layer, so it seems
best to have programs refer to the official fe* entry points in libm.
dynamic rounding modes, but FPUless chips that use softfloat can support it
because everything is emulated anyway. (We presently have incomplete
support for hardware FPUs.)
Submitted by: Ian Lepore
As I looked through the C library, I noticed the FreeBSD MIPS port has a
hand-written version of index(). This is nice, if it weren't for the
fact that most applications call strchr() instead.
Also, on the other architectures index() and strchr() are identical,
meaning we have two identical pieces of code in the C library and
statically linked applications.
Solve this by naming the actual file strchr.[cS] and let it use
__strong_reference()/STRONG_ALIAS() to provide the index() routine. Do
the same for rindex()/strrchr().
This seems to make the C libraries and static binaries slightly smaller,
but this reduction in size seems negligible.
working MI one. The MI one only needs to be overridden on machines
with non-IEEE754 arithmetic. (The last supported one was the VAX.)
It can also be overridden if someone comes up with a faster one that
actually passes the regression tests -- but this is harder than it sounds.
It's not necessary to add stdlib directories for each architecture, even
if the architecture doesn't implement any files of its own.
Submitted by: Christoph Mallon
main cycle only if the len passed is equal to 0. If end address
overflows use last possible address as the end address.
Based on: discussion on arm@
MFC after: 1 month
