see
https://sourceware.org/ml/libc-alpha/2016-01/msg00822.html

marks different RLD_MAP for debugging PIE binaries.

following
http://www.sco.com/developers/gabi/latest/ch4.sheader.html

see
https://sourceware.org/ml/libc-alpha/2015-03/msg00580.html

following
https://sourceware.org/ml/libc-alpha/2014-05/msg00332.html

add ilp32 related relocs and alternative names for a few macros following
https://sourceware.org/ml/libc-alpha/2014-11/msg00455.html

see
https://sourceware.org/ml/libc-alpha/2013-11/msg00315.html
https://sourceware.org/ml/libc-alpha/2013-11/msg00314.html

following the corresponding binutils and glibc changes
https://sourceware.org/ml/binutils/2013-10/msg00372.html

it was changed to EM_OR1K in 200d1547
as that was meant to be the official name, but glibc and the latest
gabi spec still uses the EM_OPENRISC name:
http://www.sco.com/developers/gabi/latest/ch4.eheader.html
binutils defines both macros so we should do the same for backward
compatibility.

With the exception of a fenv implementation, the port is fully featured.
The port has been tested in or1ksim, the golden reference functional
simulator for OpenRISC 1000.
It passes all libc-test tests (except the math tests that
requires a fenv implementation).

The port assumes an or1k implementation that has support for
atomic instructions (l.lwa/l.swa).

Although it passes all the libc-test tests, the port is still
in an experimental state, and has yet experienced very little
'real-world' use.

see glibc commit 9c21573c02446b3d5cf6a34b67c8545e5be6a600

the changes were verified using various sources:
linux: include/uapi/linux/elf.h
binutils: include/elf/common.h
glibc: elf/elf.h
sysv gabi: http://www.sco.com/developers/gabi/latest/contents.html
sun linker docs: http://docs.oracle.com/cd/E18752_01/pdf/817-1984.pdf
and platform specific docs

- fixed:
EF_MIPS_* E_MIPS_* e_flags: fixed accoding to glibc and binutils

- added:
ELFOSABI_GNU for EI_OSABI entry: glibc, binutils and sysv gabi
EM_* e_machine values: updated according to linux and glibc
PN_XNUM e_phnum value: from glibc and linux, see oracle docs
NT_* note types: updated according to linux and glibc
DF_1_* flags for DT_FLAGS_1 entry: following glibc and oracle docs
AT_HWCAP2 auxv entry for more hwcap bits accoding to linux and glibc
R_386_SIZE32 relocation according to glibc and binutils
EF_ARM_ABI_FLOAT_* e_flags: added following glibc and binutils
R_AARCH64_* relocs: added following glibc and aarch64 elf specs
R_ARM_* relocs: according to glibc, binutils and arm elf specs
R_X86_64_* relocs: added missing relocs following glibc

- removed:
HWCAP_SPARC_* flags were moved to arch specific header in glibc
R_ARM_SWI24 reloc is marked as obsolete in glibc, not present in binutils
  not specified in arm elf spec, R_ARM_TLS_DESC reused its number
  see http://www.codesourcery.com/publications/RFC-TLSDESC-ARM.txt

- glibc changes not pulled in:
ELFOSABI_ARM_AEABI (bare-metal system, binutils and glibc disagrees about the name)
R_68K_* relocs for unsupported platform
R_SPARC_* ditto
EF_SH* ditto (e_flags)
EF_S390* ditto (e_flags)
R_390* ditto
R_MN10300* ditto
R_TILE* ditto

based on initial work by rdp, with heavy modifications. some features
including threads are untested because qemu app-level emulation seems
to be broken and I do not have a proper system image for testing.

one file was reusing another file's macro name, and many had
inconsistent underscores and application of SYS prefix, etc.

patch by Szabolcs Nagy (nsz)