nds32: add NPTL/TLS, *context function, libm changes and code cleanup

This commit includes following features.
1. Support NPTL/TLS
2. Add libm function which is used to handle FP rounding and excpetions
   (ex: fclrexcpt,fedisblxcpti,feenablxcpt... )
3. Add *context function for operating user context
   (ex: setcontext,getcontext,makecontext... )
4. Change the return flow from signal handler
5. Cleanup of old code

The testsuite only has 2 errors, tst-cpuclock1 and tst-cputimer1,
which are related to timing accuracy. (math and locale tests are disabled)

Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>

3 files changed, 168 insertions, 1 deletions

diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
index f312e7a13..a9d62f50f 100644
--- a/extra/Configs/Config.in
+++ b/extra/Configs/Config.in
@@ -521,7 +521,6 @@ config UCLIBC_HAS_THREADS_NATIVE
 		   !TARGET_hppa && \
 		   !TARGET_ia64 && \
 		   !TARGET_m68k && \
-		   !TARGET_nds32 && \
 		   !TARGET_or1k && \
 		   ARCH_USE_MMU
 	help
diff --git a/extra/Configs/Config.nds32 b/extra/Configs/Config.nds32
index a74249947..2ed6a32b7 100644
--- a/extra/Configs/Config.nds32
+++ b/extra/Configs/Config.nds32
@@ -13,6 +13,7 @@ config FORCE_OPTIONS_FOR_ARCH
 	select ARCH_ANY_ENDIAN
 	select ARCH_HAS_DEPRECATED_SYSCALLS
 	select ARCH_HAS_MMU
+	select ARCH_HAS_UCONTEXT
 
 choice
 	prompt "MMU Page Size"
diff --git a/extra/Configs/defconfigs/nds32/defconfig b/extra/Configs/defconfigs/nds32/defconfig
new file mode 100644
index 000000000..d870ad747
--- /dev/null
+++ b/extra/Configs/defconfigs/nds32/defconfig
@@ -0,0 +1,167 @@
+TARGET_nds32=y
+#
+# Using ELF file format
+#
+ARCH_HAS_DEPRECATED_SYSCALLS=y
+ARCH_ANY_ENDIAN=y
+ARCH_LITTLE_ENDIAN=y
+# ARCH_WANTS_BIG_ENDIAN is not set
+ARCH_WANTS_LITTLE_ENDIAN=y
+ARCH_HAS_MMU=y
+ARCH_USE_MMU=y
+UCLIBC_HAS_FLOATS=y
+UCLIBC_HAS_FPU=y
+DO_C99_MATH=y
+DO_XSI_MATH=y
+UCLIBC_HAS_FENV=y
+KERNEL_HEADERS=""
+HAVE_DOT_CONFIG=y
+
+#
+# General Library Settings
+#
+DOPIC=y
+ARCH_HAS_UCONTEXT=y
+HAVE_SHARED=y
+# FORCE_SHAREABLE_TEXT_SEGMENTS is not set
+LDSO_LDD_SUPPORT=y
+LDSO_CACHE_SUPPORT=y
+# LDSO_PRELOAD_ENV_SUPPORT is not set
+# LDSO_PRELOAD_FILE_SUPPORT is not set
+LDSO_BASE_FILENAME="ld.so"
+# LDSO_STANDALONE_SUPPORT is not set
+# LDSO_PRELINK_SUPPORT is not set
+UCLIBC_STATIC_LDCONFIG=y
+LDSO_RUNPATH=y
+LDSO_RUNPATH_OF_EXECUTABLE=y
+LDSO_SAFE_RUNPATH=y
+LDSO_SEARCH_INTERP_PATH=y
+LDSO_LD_LIBRARY_PATH=y
+LDSO_NO_CLEANUP=y
+UCLIBC_CTOR_DTOR=y
+LDSO_GNU_HASH_SUPPORT=y
+# HAS_NO_THREADS is not set
+# UCLIBC_HAS_LINUXTHREADS is not set
+UCLIBC_HAS_THREADS_NATIVE=y
+UCLIBC_HAS_THREADS=y
+UCLIBC_HAS_TLS=y
+PTHREADS_DEBUG_SUPPORT=y
+UCLIBC_HAS_SYSLOG=y
+UCLIBC_HAS_LFS=y
+# MALLOC is not set
+# MALLOC_SIMPLE is not set
+MALLOC_STANDARD=y
+MALLOC_GLIBC_COMPAT=y
+# UCLIBC_HAS_OBSTACK is not set
+UCLIBC_DYNAMIC_ATEXIT=y
+COMPAT_ATEXIT=y
+UCLIBC_HAS_UTMPX=y
+UCLIBC_HAS_UTMP=y
+UCLIBC_SUSV2_LEGACY=y
+UCLIBC_SUSV3_LEGACY=y
+UCLIBC_HAS_CONTEXT_FUNCS=y
+UCLIBC_SUSV3_LEGACY_MACROS=y
+UCLIBC_SUSV4_LEGACY=y
+# UCLIBC_STRICT_HEADERS is not set
+# UCLIBC_HAS_STUBS is not set
+UCLIBC_HAS_SHADOW=y
+UCLIBC_HAS_PROGRAM_INVOCATION_NAME=y
+UCLIBC_HAS___PROGNAME=y
+UCLIBC_HAS_PTY=y
+ASSUME_DEVPTS=y
+UNIX98PTY_ONLY=y
+UCLIBC_HAS_GETPT=y
+UCLIBC_HAS_LIBUTIL=y
+UCLIBC_HAS_TM_EXTENSIONS=y
+UCLIBC_HAS_TZ_CACHING=y
+UCLIBC_HAS_TZ_FILE=y
+UCLIBC_HAS_TZ_FILE_READ_MANY=y
+UCLIBC_TZ_FILE_PATH="/etc/TZ"
+UCLIBC_FALLBACK_TO_ETC_LOCALTIME=y
+
+#
+# Advanced Library Settings
+#
+UCLIBC_PWD_BUFFER_SIZE=256
+UCLIBC_GRP_BUFFER_SIZE=256
+
+#
+# Support various families of functions
+#
+UCLIBC_LINUX_MODULE_26=y
+# UCLIBC_LINUX_MODULE_24 is not set
+UCLIBC_LINUX_SPECIFIC=y
+UCLIBC_HAS_GNU_ERROR=y
+UCLIBC_BSD_SPECIFIC=y
+UCLIBC_HAS_BSD_ERR=y
+UCLIBC_HAS_OBSOLETE_BSD_SIGNAL=y
+# UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL is not set
+# UCLIBC_NTP_LEGACY is not set
+UCLIBC_SV4_DEPRECATED=y
+UCLIBC_HAS_REALTIME=y
+UCLIBC_HAS_ADVANCED_REALTIME=y
+UCLIBC_HAS_EPOLL=y
+UCLIBC_HAS_XATTR=y
+UCLIBC_HAS_PROFILING=y
+UCLIBC_HAS_CRYPT_IMPL=y
+UCLIBC_HAS_SHA256_CRYPT_IMPL=y
+# UCLIBC_HAS_SHA512_CRYPT_IMPL is not set
+UCLIBC_HAS_CRYPT=y
+UCLIBC_HAS_NETWORK_SUPPORT=y
+UCLIBC_HAS_SOCKET=y
+UCLIBC_HAS_IPV4=y
+UCLIBC_HAS_IPV6=y
+UCLIBC_HAS_RPC=y
+UCLIBC_HAS_FULL_RPC=y
+# UCLIBC_HAS_REENTRANT_RPC is not set
+UCLIBC_USE_NETLINK=y
+UCLIBC_SUPPORT_AI_ADDRCONFIG=y
+UCLIBC_HAS_BSD_RES_CLOSE=y
+UCLIBC_HAS_COMPAT_RES_STATE=y
+# UCLIBC_HAS_EXTRA_COMPAT_RES_STATE is not set
+UCLIBC_HAS_RESOLVER_SUPPORT=y
+UCLIBC_HAS_LIBRESOLV_STUB=y
+UCLIBC_HAS_LIBNSL_STUB=y
+
+UCLIBC_HAS_STRING_GENERIC_OPT=y
+UCLIBC_HAS_STRING_ARCH_OPT=y
+UCLIBC_HAS_STDIO_FUTEXES=y
+UCLIBC_HAS_CTYPE_TABLES=y
+UCLIBC_HAS_CTYPE_SIGNED=y
+# UCLIBC_HAS_CTYPE_UNSAFE is not set
+UCLIBC_HAS_CTYPE_CHECKED=y
+# UCLIBC_HAS_CTYPE_ENFORCED is not set
+UCLIBC_HAS_WCHAR=y
+# UCLIBC_HAS_LOCALE is not set
+UCLIBC_HAS_HEXADECIMAL_FLOATS=y
+UCLIBC_HAS_GLIBC_CUSTOM_PRINTF=y
+UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS=9
+UCLIBC_HAS_STDIO_BUFSIZ_4096=y
+UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE=y
+UCLIBC_HAS_STDIO_GETC_MACRO=y
+UCLIBC_HAS_STDIO_PUTC_MACRO=y
+UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION=y
+UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE=y
+UCLIBC_HAS_GLIBC_CUSTOM_STREAMS=y
+UCLIBC_HAS_PRINTF_M_SPEC=y
+UCLIBC_HAS_ERRNO_MESSAGES=y
+UCLIBC_HAS_SIGNUM_MESSAGES=y
+UCLIBC_HAS_GNU_GETOPT=y
+UCLIBC_HAS_GETOPT_LONG=y
+UCLIBC_HAS_GNU_GETSUBOPT=y
+UCLIBC_HAS_ARGP=y
+
+UCLIBC_HAS_REGEX=y
+# UCLIBC_HAS_REGEX_OLD is not set
+UCLIBC_HAS_FNMATCH=y
+# UCLIBC_HAS_FNMATCH_OLD is not set
+UCLIBC_HAS_WORDEXP=y
+UCLIBC_HAS_NFTW=y
+UCLIBC_HAS_FTW=y
+UCLIBC_HAS_FTS=y
+UCLIBC_HAS_GLOB=y
+UCLIBC_HAS_GNU_GLOB=y
+
+CROSS_COMPILER_PREFIX=""
+UCLIBC_EXTRA_CFLAGS=""
+# DOSTRIP is not set