Do not submit this patch before the one that modifies the Android emulator to
work-around a weird ARMv7 emulation issue. This is done to temporarily re-allow
the -user builds needed for QA.
This is required to work-around some corny bugs in ARMv7 emulation.
The emulation itself is required to run the dex pre-optimization pass
for -user builds.
Merge commit '7a9e06fa7e4e533074cde314f25dff3024f34a5d' into eclair-plus-aosp
* commit '7a9e06fa7e4e533074cde314f25dff3024f34a5d':
Fix ABI breakage in libc.so and libm.so between 1.6 and Eclair.
372 MB/s for large transfers, 440 MB/s for smaller ones down to 1KB. 130 MB/s for very small transfers ( < 32 bytes )
Performance is similar with non-congruent buffers.
For performance reasons, we don't call the kernel helper. Instead, we directly
access the TLS register on ARMv6 and higher. For ARMv5TE, keep using the hard-coded
address populated by the kernel on each task switch.
NOTE: Since we don't call the kernel helper, this must precisely match your
kernel configuration. This is controlled by setting the ARCH_ARM_HAVE_TLS_REGISTER
variable to 'true' in your board configuration file.
ARMv6 onwards. These architectures provide the load-linked, store-conditional pair of ldrex/strex whose use
is recommended in place of 'swp'. Also, the description of the 'swp' instruction in the ARMv6 reference
manual states that the swap operation does not include any memory barrier guarantees.This fix attempts to
address these issues by providing an atomic swap implementation using ldrex/strex under _ARM_HAVE_LDREX_STREX
macro. This Fix is verified on ST Ericsson's U8500 platform and Submitted on behalf of a third-party:
Surinder-pal SINGH from STMicroelectronics.
The problem was due to the fact that, in the case of dynamic executables,
the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
constructors when loading shared libraries and dynamic executables,
*before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
The latter did call these constructors array again, mistakenly.
The patch also updates the documentation of many related functions.
Also adds a new section to linker/README.TXT explaining restrictions on
C library usage.
The patch has been tested on a Dream for stability issues with
proprietary blobs:
- H264 decoding works
- Camera + Video recording works
- GPS works
- Sensors work
The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
run and shows the static C++ constructor being called only once.
