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2015-11-10explicitly assemble all arm asm sources as UALRich Felker2-0/+4
these files are all accepted as legacy arm syntax when producing arm code, but legacy syntax cannot be used for producing thumb2 with access to the full ISA. even after switching to UAL, some asm source files contain instructions which are not valid in thumb mode, so these will need to be addressed separately.
2015-11-09remove non-working pre-armv4t support from arm asmRich Felker1-4/+0
the idea of the three-instruction sequence being removed was to be able to return to thumb code when used on armv4t+ from a thumb caller, but also to be able to run on armv4 without the bx instruction available (in which case the low bit of lr would always be 0). however, without compiler support for generating such a sequence from C code, which does not exist and which there is unlikely to be interest in implementing, there is little point in having it in the asm, and it would likely be easier to add pre-armv4t support via enhanced linker handling of R_ARM_V4BX than at the compiler level. removing this code simplifies adding support for building libc in thumb2-only form (for cortex-m).
2015-10-14remove hand-written crt1.s and Scrt1.s files for all archsRich Felker2-47/+0
since commit c5e34dabbb47d8e97a4deccbb421e0cd93c0094b, crt1.c has provided a "mostly-C" implementation of the crt1 start file that avoids the need for arch-specific symbol referencing, PIC/PIE-specific code variants, etc. but for archs that had existing hand-written versions, the new code was initially unused, and later only used as the dynamic linker entry point. this commit switches all archs to using the new code. the code being removed was a recurring source of subtle errors, and was still broken at least on arm, where it failed to properly align the stack pointer before calling into C code.
2013-08-15add function types to arm crt assemblyRich Felker2-0/+3
without these, calls may be resolved incorrectly if the calling code has been compiled to thumb instead of arm. it's not clear to me at this point whether crt_arch.h is even working if crt1.c is built as thumb; this needs testing. but the _init and _fini issues were known to cause crashes in static-linked apps when libc was built as thumb, and this commit should fix that issue.
2013-07-21remove init/fini array asm from arm crti/crtn filesRich Felker2-44/+4
this code has been replaced by portable C code that works on all archs. the old asm needs to be removed or ctors/dtors will run twice.
2013-07-10add PIE support for ARMRich Felker1-0/+30
2013-02-03fix regression that made shared libs crash on armRich Felker2-0/+4
2012-12-07add support for ctors/dtors on arm with modern gccRich Felker2-4/+40
a while back, gcc switched from using the old _init/_fini fragments method for calling ctors and dtors on arm to the __init_array and __fini_array method. unfortunately, on glibc this depends on ugly hacks involving making libc.so a linker script and pulling parts of libc into the main program binary. so I cheat a little bit, and just write asm to iterate over the init/fini arrays from the _init/_fini asm. the same approach could be used on any arch it's needed on, but for now arm is the only one.
2012-06-25fix arm crti/crtn codeRich Felker2-0/+4
lr must be saved because init/fini-section code from the compiler clobbers it. this was not a problem when i tested without gcc's crtbegin/crtend files present, but with them, musl on arm fails to work (infinite loop in _init).
2012-02-06add support for init/finit (constructors and destructors)Rich Felker3-2/+21
this is mainly in hopes of supporting c++ (not yet possible for other reasons) but will also help applications/libraries which use (and more often, abuse) the gcc __attribute__((__constructor__)) feature in "C" code. x86_64 and arm versions of the new startup asm are untested and may have minor problems.
2011-09-18initial commit of the arm portRich Felker1-0/+13
this port assumes eabi calling conventions, eabi linux syscall convention, and presence of the kernel helpers at 0xffff0f?0 needed for threads support. otherwise it makes very few assumptions, and the code should work even on armv4 without thumb support, as well as on systems with thumb interworking. the bits headers declare this a little endian system, but as far as i can tell the code should work equally well on big endian. some small details are probably broken; so far, testing has been limited to qemu/aboriginal linux.