From f43a1dc55d42de3097f75ca65baead9a2ff05c78 Mon Sep 17 00:00:00 2001 From: Dmitry Kolesnikov Date: Tue, 11 Feb 2014 00:27:11 +0200 Subject: Raspberry PI / Android a minimal cross-compile configuration Enable a cross compile Erlang/OTP platform to Android or Raspberry PI using Android NDK. Port emulator and core application to support target HW platform. Exclude any add-on services required for OTP platform deployment into target hardware due to device fragmentation and jail-break requirements. * fix erts/emulator/beam/sys.h Disable redefinition of __noreturn macro * port erts/emulator/sys/unix/erl_child_setup.c Use techniques proposed by https://code.google.com/p/erlang4android to access system properties * fix erts/emulator/sys/unix/erl_unix_sys_ddll.c The static linking of emulator cannot find dlerror(), dlopen() symbols * port erts/emulator/sys/unix/sys.c make path to shell configurable at build time * port erts/etc/common/Makefile.in disable librt for *-linux-androideabi * port erts/lib_src/pthread/ethread.c Use techniques proposed by https://code.google.com/p/erlang4android to disable emulator crash if kernel threads are on. Replace unreliable pthread_sigmask() by sigprocmask() * port lib/erl_interface/src/connect/ei_connect.c Disable call to undefined gethostid() * port lib/erl_interface/src/connect/ei_resolve.c Use gethostbyname_r() on Android platform --- HOWTO/INSTALL-ANDROID.md | 52 ++++++ erts/emulator/Makefile.in | 2 + erts/emulator/beam/sys.h | 6 +- erts/emulator/sys/unix/erl_child_setup.c | 39 ++++- erts/emulator/sys/unix/erl_unix_sys_ddll.c | 4 + erts/emulator/sys/unix/sys.c | 11 +- erts/etc/common/Makefile.in | 2 + erts/lib_src/pthread/ethread.c | 6 +- lib/erl_interface/src/connect/ei_connect.c | 4 + lib/erl_interface/src/connect/ei_resolve.c | 2 +- lib/kernel/src/os.erl | 11 +- lib/os_mon/c_src/memsup.c | 8 +- xcomp/erl-xcomp-arm-android.conf | 264 +++++++++++++++++++++++++++++ 13 files changed, 401 insertions(+), 10 deletions(-) create mode 100644 HOWTO/INSTALL-ANDROID.md create mode 100644 xcomp/erl-xcomp-arm-android.conf diff --git a/HOWTO/INSTALL-ANDROID.md b/HOWTO/INSTALL-ANDROID.md new file mode 100644 index 0000000000..31698d4ce3 --- /dev/null +++ b/HOWTO/INSTALL-ANDROID.md @@ -0,0 +1,52 @@ +Cross Compiling Erlang/OTP - ANDROID +==================================== + +Introduction +------------ + +This document describes how to cross compile Erlang OTP to Android/Rasberry Pi platforms. + +### Download and Install Android NDK ### + +https://developer.android.com/tools/sdk/ndk/index.html + +### Define System Variables ### + +export NDK_ROOT=/usr/local/android +export NDK_PLAT=android-9 +export PATH=$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/bin:$PATH + +### Configure OTP ### + +./otp_build configure \ + --xcomp-conf=./xcomp/erl-xcomp-arm-android.conf \ + --without-ssl + +### Compile OTP ### + +make noboot [-j4] + +### Make Release ### + +./otp_build release -a /usr/local/otp_R16B03_arm + +### Target Deployment ### + +Make a tarball out of /usr/local/otp_R16B03_arm and copy it to target device +(e.g. Raspberry Pi). Extract it and install + +./Install /usr/local/otp_R16B03_arm + +Android SDK (adb tool) is used to deploy OTP/Erlang to target device for +evaluation purpose only. + +adb push /usr/local/otp_R16B03_arm /mnt/sdcard/otp_R16B03_arm +adb shell + +### Known Issues ### + + * native inet:gethostbyname/1 return {error, nxdomain} on Raspberry PI. Use dns resolver to by-pass the issue (see http://www.erlang.org/doc/apps/erts/inet_cfg.html) + +### References ### + + The port derives some solutions from https://code.google.com/p/erlang4android/ diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in index 2a9a0a5c2f..58e77ed1fa 100644 --- a/erts/emulator/Makefile.in +++ b/erts/emulator/Makefile.in @@ -378,7 +378,9 @@ LIBS += -l$(ERTS_INTERNAL_LIB)$(TYPEMARKER) endif # erts_internal_r +ifneq ($(TARGET),arm-unknown-linux-androideabi) LIBS += @LIBRT@ +endif LIBS += @LIBCARBON@ diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h index e273056a2b..05f07e57b2 100644 --- a/erts/emulator/beam/sys.h +++ b/erts/emulator/beam/sys.h @@ -154,10 +154,14 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType; /* In VC++, noreturn is a declspec that has to be before the types, * but in GNUC it is an att ribute to be placed between return type * and function name, hence __decl_noreturn __noreturn + * + * at some platforms (e.g. Android) __noreturn is defined at sys/cdef.h */ #if __GNUC__ # define __decl_noreturn -# define __noreturn __attribute__((noreturn)) +# ifndef __noreturn +# define __noreturn __attribute__((noreturn)) +# endif #else # if defined(__WIN32__) && defined(_MSC_VER) # define __noreturn diff --git a/erts/emulator/sys/unix/erl_child_setup.c b/erts/emulator/sys/unix/erl_child_setup.c index 7c6e4a2f37..34d7f9e0e5 100644 --- a/erts/emulator/sys/unix/erl_child_setup.c +++ b/erts/emulator/sys/unix/erl_child_setup.c @@ -54,6 +54,17 @@ void sys_sigrelease(int sig) #endif /* !SIG_SIGNAL */ #endif /* !SIG_SIGSET */ +#if defined(__ANDROID__) +int __system_properties_fd(void); +#endif /* __ANDROID__ */ + +#if defined(__ANDROID__) +#define SHELL "/system/bin/sh" +#else +#define SHELL "/bin/sh" +#endif /* __ANDROID__ */ + + int main(int argc, char *argv[]) { @@ -89,8 +100,16 @@ main(int argc, char *argv[]) if (sscanf(argv[CS_ARGV_FD_CR_IX], "%d:%d", &from, &to) != 2) return 1; + +#if defined(__ANDROID__) + for (i = from; i <= to; i++) { + if (i!=__system_properties_fd) + (void) close(i); + } +#else for (i = from; i <= to; i++) (void) close(i); +#endif /* __ANDROID__ */ if (!(argv[CS_ARGV_WD_IX][0] == '.' && argv[CS_ARGV_WD_IX][1] == '\0') && chdir(argv[CS_ARGV_WD_IX]) < 0) @@ -116,7 +135,25 @@ main(int argc, char *argv[]) execv(argv[CS_ARGV_NO_OF_ARGS],&(argv[CS_ARGV_NO_OF_ARGS + 1])); } } else { - execl("/bin/sh", "sh", "-c", argv[CS_ARGV_CMD_IX], (char *) NULL); + execl(SHELL, "sh", "-c", argv[CS_ARGV_CMD_IX], (char *) NULL); } return 1; } + + + +#if defined(__ANDROID__) +int __system_properties_fd(void) +{ + int s, fd; + char *env; + + env = getenv("ANDROID_PROPERTY_WORKSPACE"); + if (!env) { + return -1; + } + fd = atoi(env); + return fd; +} +#endif /* __ANDROID__ */ + diff --git a/erts/emulator/sys/unix/erl_unix_sys_ddll.c b/erts/emulator/sys/unix/erl_unix_sys_ddll.c index 8760b58839..2659d623c7 100644 --- a/erts/emulator/sys/unix/erl_unix_sys_ddll.c +++ b/erts/emulator/sys/unix/erl_unix_sys_ddll.c @@ -123,6 +123,7 @@ int erts_sys_ddll_open(const char *full_name, void **handle, ErtsSysDdllError* e int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err) { +#if defined(HAVE_DLOPEN) int ret = ERL_DE_NO_ERROR; char *str; dlerror(); @@ -148,6 +149,9 @@ int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err) ret = ERL_DE_DYNAMIC_ERROR_OFFSET - find_errcode(str, err); } return ret; +#else + return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY; +#endif } /* diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c index 865cb50a56..c3d7440409 100644 --- a/erts/emulator/sys/unix/sys.c +++ b/erts/emulator/sys/unix/sys.c @@ -149,6 +149,13 @@ extern void erl_crash_dump(char* file, int line, char* fmt, ...); #define DIR_SEPARATOR_CHAR '/' +#if defined(__ANDROID__) +#define SHELL "/system/bin/sh" +#else +#define SHELL "/bin/sh" +#endif /* __ANDROID__ */ + + #if defined(DEBUG) #define ERL_BUILD_TYPE_MARKER ".debug" #elif defined(PURIFY) @@ -1596,7 +1603,7 @@ static ErlDrvData spawn_start(ErlDrvPort port_num, char* name, SysDriverOpts* op } } } else { - execle("/bin/sh", "sh", "-c", cmd_line, (char *) NULL, new_environ); + execle(SHELL, "sh", "-c", cmd_line, (char *) NULL, new_environ); } child_error: _exit(1); @@ -1717,7 +1724,7 @@ static ErlDrvData spawn_start(ErlDrvPort port_num, char* name, SysDriverOpts* op fcntl(i, F_SETFD, 1); qnx_spawn_options.flags = _SPAWN_SETSID; - if ((pid = spawnl(P_NOWAIT, "/bin/sh", "/bin/sh", "-c", cmd_line, + if ((pid = spawnl(P_NOWAIT, SHELL, SHELL, "-c", cmd_line, (char *) 0)) < 0) { erts_free(ERTS_ALC_T_TMP, (void *) cmd_line); reset_qnx_spawn(); diff --git a/erts/etc/common/Makefile.in b/erts/etc/common/Makefile.in index 5c2cd8aded..cfd36af962 100644 --- a/erts/etc/common/Makefile.in +++ b/erts/etc/common/Makefile.in @@ -66,7 +66,9 @@ LIBS = @LIBS@ LDFLAGS = @LDFLAGS@ # For clock_gettime in heart +ifneq ($(TARGET),arm-unknown-linux-androideabi) RTLIBS = @LIBRT@ +endif ifeq ($(TARGET),win32) ifeq ($(TYPE),debug) diff --git a/erts/lib_src/pthread/ethread.c b/erts/lib_src/pthread/ethread.c index 7f27b5f29c..79784c5b84 100644 --- a/erts/lib_src/pthread/ethread.c +++ b/erts/lib_src/pthread/ethread.c @@ -541,7 +541,11 @@ int ethr_sigmask(int how, const sigset_t *set, sigset_t *oset) return EINVAL; } #endif - return pthread_sigmask(how, set, oset); +#if defined(__ANDROID__) + return sigprocmask(how, set, oset); +#else + return pthread_sigmask(how, set, oset); +#endif } int ethr_sigwait(const sigset_t *set, int *sig) diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c index 3175d1bdfd..2e8418d61e 100644 --- a/lib/erl_interface/src/connect/ei_connect.c +++ b/lib/erl_interface/src/connect/ei_connect.c @@ -1166,7 +1166,11 @@ static unsigned int gen_challenge(void) uname(&s.name); s.cpu = clock(); s.pid = getpid(); +#ifndef __ANDROID__ s.hid = gethostid(); +#else + s.hid = 0; +#endif s.uid = getuid(); s.gid = getgid(); diff --git a/lib/erl_interface/src/connect/ei_resolve.c b/lib/erl_interface/src/connect/ei_resolve.c index 74dcba61a7..cffcac801c 100644 --- a/lib/erl_interface/src/connect/ei_resolve.c +++ b/lib/erl_interface/src/connect/ei_resolve.c @@ -642,7 +642,7 @@ struct hostent *ei_gethostbyname_r(const char *name, #ifndef HAVE_GETHOSTBYNAME_R return my_gethostbyname_r(name,hostp,buffer,buflen,h_errnop); #else -#if (defined(__GLIBC__) || (__FreeBSD_version >= 602000) || defined(__DragonFly__)) +#if (defined(__GLIBC__) || (__FreeBSD_version >= 602000) || defined(__DragonFly__) || defined(__ANDROID__)) struct hostent *result; gethostbyname_r(name, hostp, buffer, buflen, &result, h_errnop); diff --git a/lib/kernel/src/os.erl b/lib/kernel/src/os.erl index 9ffa9adeab..3bda391b8e 100644 --- a/lib/kernel/src/os.erl +++ b/lib/kernel/src/os.erl @@ -230,7 +230,9 @@ unix_cmd(Cmd) -> %% and the commands are read from standard input. We set the %% $1 parameter for easy identification of the resident shell. %% --define(SHELL, "/bin/sh -s unix:cmd 2>&1"). +-define(ROOT, "/"). +-define(ROOT_ANDROID, "/system"). +-define(SHELL, "bin/sh -s unix:cmd 2>&1"). -define(PORT_CREATOR_NAME, os_cmd_port_creator). %% @@ -280,7 +282,12 @@ start_port_srv(Request) -> end. start_port_srv_handle({Ref,Client}) -> - Reply = try open_port({spawn, ?SHELL},[stream]) of + Path = case lists:reverse(erlang:system_info(system_architecture)) of + % androideabi + "ibaediordna" ++ _ -> filename:join([?ROOT_ANDROID, ?SHELL]); + _ -> filename:join([?ROOT, ?SHELL]) + end, + Reply = try open_port({spawn, Path},[stream]) of Port when is_port(Port) -> (catch port_connect(Port, Client)), unlink(Port), diff --git a/lib/os_mon/c_src/memsup.c b/lib/os_mon/c_src/memsup.c index b5114d10ed..409db84aa7 100644 --- a/lib/os_mon/c_src/memsup.c +++ b/lib/os_mon/c_src/memsup.c @@ -324,7 +324,7 @@ get_mem_procfs(memory_ext *me){ /* arch specific functions */ -#if defined(__linux__) /* ifdef SYSINFO */ +#if defined(__linux__) && !defined(__ANDROID__)/* ifdef SYSINFO */ /* sysinfo does not include cached memory which is a problem. */ static int get_extended_mem_sysinfo(memory_ext *me) { @@ -395,8 +395,12 @@ get_extended_mem_sgi(memory_ext *me) { static void get_extended_mem(memory_ext *me) { +/* android */ +#if defined(__ANDROID__) + if (get_mem_procfs(me)) return; + /* linux */ -#if defined(__linux__) +#elif defined(__linux__) if (get_mem_procfs(me)) return; if (get_extended_mem_sysinfo(me)) return; diff --git a/xcomp/erl-xcomp-arm-android.conf b/xcomp/erl-xcomp-arm-android.conf new file mode 100644 index 0000000000..4fd1f270d1 --- /dev/null +++ b/xcomp/erl-xcomp-arm-android.conf @@ -0,0 +1,264 @@ +## -*-shell-script-*- +## +## %CopyrightBegin% +## +## Copyright Ericsson AB 2009-2010. All Rights Reserved. +## +## The contents of this file are subject to the Erlang Public License, +## Version 1.1, (the "License"); you may not use this file except in +## compliance with the License. You should have received a copy of the +## Erlang Public License along with this software. If not, it can be +## retrieved online at http://www.erlang.org/. +## +## Software distributed under the License is distributed on an "AS IS" +## basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +## the License for the specific language governing rights and limitations +## under the License. +## +## %CopyrightEnd% +## +## File: erl-xcomp.conf.template +## Author: +## +## ----------------------------------------------------------------------------- +## When cross compiling Erlang/OTP using `otp_build', copy this file and set +## the variables needed below. Then pass the path to the copy of this file as +## an argument to `otp_build' in the configure stage: +## `otp_build configure --xcomp-conf=' +## ----------------------------------------------------------------------------- + +## Note that you cannot define arbitrary variables in a cross compilation +## configuration file. Only the ones listed below will be guaranteed to be +## visible throughout the whole execution of all `configure' scripts. Other +## variables needs to be defined as arguments to `configure' or exported in +## the environment. + +## -- Variables for `otp_build' Only ------------------------------------------- + +## Variables in this section are only used, when configuring Erlang/OTP for +## cross compilation using `$ERL_TOP/otp_build configure'. + +## *NOTE*! These variables currently have *no* effect if you configure using +## the `configure' script directly. + +# * `erl_xcomp_build' - The build system used. This value will be passed as +# `--build=$erl_xcomp_build' argument to the `configure' script. It does +# not have to be a full `CPU-VENDOR-OS' triplet, but can be. The full +# `CPU-VENDOR-OS' triplet will be created by +# `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_build'. If set to `guess', +# the build system will be guessed using +# `$ERL_TOP/erts/autoconf/config.guess'. +erl_xcomp_build=guess + +# * `erl_xcomp_host' - Cross host/target system to build for. This value will +# be passed as `--host=$erl_xcomp_host' argument to the `configure' script. +# It does not have to be a full `CPU-VENDOR-OS' triplet, but can be. The +# full `CPU-VENDOR-OS' triplet will be created by +# `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_host'. +erl_xcomp_host=arm-linux-androideabi + +# * `erl_xcomp_configure_flags' - Extra configure flags to pass to the +# `configure' script. +erl_xcomp_configure_flags="--disable-hipe --without-termcap" + + +## -- Cross Compiler and Other Tools ------------------------------------------- + +## +## +NDK_SYSROOT=$NDK_ROOT/platforms/$NDK_PLAT/arch-arm + +## If the cross compilation tools are prefixed by `-' you probably do +## not need to set these variables (where `' is what has been passed as +## `--host=' argument to `configure'). + +## All variables in this section can also be used when native compiling. + +# * `CC' - C compiler. +CC="arm-linux-androideabi-gcc --sysroot=$NDK_SYSROOT" + +# * `CFLAGS' - C compiler flags. +CFLAGS="-static -march=armv7-a -msoft-float -mthumb" + +# * `STATIC_CFLAGS' - Static C compiler flags. +#STATIC_CFLAGS= + +# * `CFLAG_RUNTIME_LIBRARY_PATH' - This flag should set runtime library +# search path for the shared libraries. Note that this actually is a +# linker flag, but it needs to be passed via the compiler. +#CFLAG_RUNTIME_LIBRARY_PATH= + +# * `CPP' - C pre-processor. +CPP="arm-linux-androideabi-cpp --sysroot=$NDK_SYSROOT" + +# * `CPPFLAGS' - C pre-processor flags. +CPPFLAGS="-static -march=armv7-a -msoft-float -mthumb" + +# * `CXX' - C++ compiler. +CXX="arm-linux-androideabi-c++ --sysroot=$NDK_SYSROOT" + +# * `CXXFLAGS' - C++ compiler flags. +CXXFLAGS="-static -march=armv7-a -msoft-float -mthumb" + +# * `LD' - Linker. +#LD= + +# * `LDFLAGS' - Linker flags. +LDFLAGS="-static -march=armv7-a -msoft-float -mthumb" + +# * `LIBS' - Libraries. +#LIBS= + +## -- *D*ynamic *E*rlang *D*river Linking -- + +## *NOTE*! Either set all or none of the `DED_LD*' variables. + +# * `DED_LD' - Linker for Dynamically loaded Erlang Drivers. +#DED_LD= + +# * `DED_LDFLAGS' - Linker flags to use with `DED_LD'. +#DED_LDFLAGS= + +# * `DED_LD_FLAG_RUNTIME_LIBRARY_PATH' - This flag should set runtime library +# search path for shared libraries when linking with `DED_LD'. +#DED_LD_FLAG_RUNTIME_LIBRARY_PATH= + +## -- Large File Support -- + +## *NOTE*! Either set all or none of the `LFS_*' variables. + +# * `LFS_CFLAGS' - Large file support C compiler flags. +#LFS_CFLAGS= + +# * `LFS_LDFLAGS' - Large file support linker flags. +#LFS_LDFLAGS= + +# * `LFS_LIBS' - Large file support libraries. +#LFS_LIBS= + +## -- Other Tools -- + +# * `RANLIB' - `ranlib' archive index tool. +#RANLIB= + +# * `AR' - `ar' archiving tool. +#AR= + +# * `GETCONF' - `getconf' system configuration inspection tool. `getconf' is +# currently used for finding out large file support flags to use, and +# on Linux systems for finding out if we have an NPTL thread library or +# not. +#GETCONF= + +## -- Cross System Root Locations ---------------------------------------------- + +# * `erl_xcomp_sysroot' - The absolute path to the system root of the cross +# compilation environment. Currently, the `crypto', `odbc', `ssh' and +# `ssl' applications need the system root. These applications will be +# skipped if the system root has not been set. The system root might be +# needed for other things too. If this is the case and the system root +# has not been set, `configure' will fail and request you to set it. +erl_xcomp_sysroot="$NDK_SYSROOT" + + +# * `erl_xcomp_isysroot' - The absolute path to the system root for includes +# of the cross compilation environment. If not set, this value defaults +# to `$erl_xcomp_sysroot', i.e., only set this value if the include system +# root path is not the same as the system root path. +#erl_xcomp_isysroot= + +## -- Optional Feature, and Bug Tests ------------------------------------------ + +## These tests cannot (always) be done automatically when cross compiling. You +## usually do not need to set these variables. Only set these if you really +## know what you are doing. + +## Note that some of these values will override results of tests performed +## by `configure', and some will not be used until `configure' is sure that +## it cannot figure the result out. + +## The `configure' script will issue a warning when a default value is used. +## When a variable has been set, no warning will be issued. + +# * `erl_xcomp_after_morecore_hook' - `yes|no'. Defaults to `no'. If `yes', +# the target system must have a working `__after_morecore_hook' that can be +# used for tracking used `malloc()' implementations core memory usage. +# This is currently only used by unsupported features. +#erl_xcomp_after_morecore_hook= + +# * `erl_xcomp_bigendian' - `yes|no'. No default. If `yes', the target system +# must be big endian. If `no', little endian. This can often be +# automatically detected, but not always. If not automatically detected, +# `configure' will fail unless this variable is set. Since no default +# value is used, `configure' will try to figure this out automatically. +#erl_xcomp_bigendian= + +# * `erl_xcomp_clock_gettime_cpu_time' - `yes|no'. Defaults to `no'. If `yes', +# the target system must have a working `clock_gettime()' implementation +# that can be used for retrieving process CPU time. +#erl_xcomp_clock_gettime_cpu_time= + +# * `erl_xcomp_getaddrinfo' - `yes|no'. Defaults to `no'. If `yes', the target +# system must have a working `getaddrinfo()' implementation that can +# handle both IPv4 and IPv6. +#erl_xcomp_getaddrinfo= + +# * `erl_xcomp_gethrvtime_procfs_ioctl' - `yes|no'. Defaults to `no'. If `yes', +# the target system must have a working `gethrvtime()' implementation and +# is used with procfs `ioctl()'. +#erl_xcomp_gethrvtime_procfs_ioctl= + +# * `erl_xcomp_dlsym_brk_wrappers' - `yes|no'. Defaults to `no'. If `yes', the +# target system must have a working `dlsym(RTLD_NEXT, )' implementation +# that can be used on `brk' and `sbrk' symbols used by the `malloc()' +# implementation in use, and by this track the `malloc()' implementations +# core memory usage. This is currently only used by unsupported features. +#erl_xcomp_dlsym_brk_wrappers= + +# * `erl_xcomp_kqueue' - `yes|no'. Defaults to `no'. If `yes', the target +# system must have a working `kqueue()' implementation that returns a file +# descriptor which can be used by `poll()' and/or `select()'. If `no' and +# the target system has not got `epoll()' or `/dev/poll', the kernel-poll +# feature will be disabled. +#erl_xcomp_kqueue= + +# * `erl_xcomp_linux_clock_gettime_correction' - `yes|no'. Defaults to `yes' on +# Linux; otherwise, `no'. If `yes', `clock_gettime(CLOCK_MONOTONIC, _)' on +# the target system must work. This variable is recommended to be set to +# `no' on Linux systems with kernel versions less than 2.6. +#erl_xcomp_linux_clock_gettime_correction= + +# * `erl_xcomp_linux_nptl' - `yes|no'. Defaults to `yes' on Linux; otherwise, +# `no'. If `yes', the target system must have NPTL (Native POSIX Thread +# Library). Older Linux systems have LinuxThreads instead of NPTL (Linux +# kernel versions typically less than 2.6). +#erl_xcomp_linux_nptl= + +# * `erl_xcomp_linux_usable_sigaltstack' - `yes|no'. Defaults to `yes' on Linux; +# otherwise, `no'. If `yes', `sigaltstack()' must be usable on the target +# system. `sigaltstack()' on Linux kernel versions less than 2.4 are +# broken. +#erl_xcomp_linux_usable_sigaltstack= + +# * `erl_xcomp_linux_usable_sigusrx' - `yes|no'. Defaults to `yes'. If `yes', +# the `SIGUSR1' and `SIGUSR2' signals must be usable by the ERTS. Old +# LinuxThreads thread libraries (Linux kernel versions typically less than +# 2.2) used these signals and made them unusable by the ERTS. +#erl_xcomp_linux_usable_sigusrx= + +# * `erl_xcomp_poll' - `yes|no'. Defaults to `no' on Darwin/MacOSX; otherwise, +# `yes'. If `yes', the target system must have a working `poll()' +# implementation that also can handle devices. If `no', `select()' will be +# used instead of `poll()'. +#erl_xcomp_poll= + +# * `erl_xcomp_putenv_copy' - `yes|no'. Defaults to `no'. If `yes', the target +# system must have a `putenv()' implementation that stores a copy of the +# key/value pair. +#erl_xcomp_putenv_copy= + +# * `erl_xcomp_reliable_fpe' - `yes|no'. Defaults to `no'. If `yes', the target +# system must have reliable floating point exceptions. +#erl_xcomp_reliable_fpe= + +## ----------------------------------------------------------------------------- -- cgit v1.2.3