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diff --git a/erts/etc/vxworks/README.VxWorks b/erts/etc/vxworks/README.VxWorks new file mode 100644 index 0000000000..299e35b513 --- /dev/null +++ b/erts/etc/vxworks/README.VxWorks @@ -0,0 +1,350 @@ + + %CopyrightBegin% + + Copyright Ericsson AB 1997-2009. 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% + +----------------------------------------------------------------------- +README, Erlang/OTP R11B for VxWorks on PPC860 and PPC603 +----------------------------------------------------------------------- +20060515 -- Patrik Nyblom, [email protected] + +R11B is a libraries only release for VxWorks. Only the libraries of +erl_interface (ei+erl_inteface) and ic are expected to be used. Still +the whole erlang system is distributed, although no support will be +given for anything else but the libraries. The information in this +file still applies to the full erlang distribution and parts of it are +therefore somewhat irrelevant to commercial users. + + +Included OTP applications +------------------------- + +appmon +asn1 +compiler +cosEvent +cosNotification +cosTime +cosTransaction +debugger +erl_interface +erts +eva [1] +ic +inets [2] +jinterface +kernel +mesh +mnemosyne +mnesia [1] +mnesia_session +orber +os_mon +pman +runtime_tools +sasl +snmp +stdlib +tools +tv + +[1] Only ram_copies work, The VxWorks filesystems are not + reliable enough for disk_copies to be fully supported. +[2] CGI scripts do not work on VxWorks. + +Omitted applications +-------------------- + +crypto +emacs +etk +gs +odbc +parsetools +toolbar +ssl +megaco +webtools + +As `crypto' and `ssl' provides cryptographic functionality to `inets' +and `snmp', the latter applications will not handle cryptography on +VxWorks. + +Graphical interfaces +-------------------- + +For applications using graphical interfaces, only the backend part works. + +Compilers +--------- + +All compilers are expected to be run on a cross host. The VxWorks +systems memory capabilities are too restricting to allow native +compiling. The expected host system is a Sun Solaris machine, although +Erlang compilation may be done on most platforms. + +Supported boards and configuration (only libraries supported) +---------------------------------- +The following boards and configurations are supported: + +* Force PowerCore 603 with Force pcore603 BSP and VxWorks 3.5.1 (no + SENS or SENS 1.1 + SPR23938) and a minimum of 32 Mb memory. + +* Force Powercore 750 with Force pcore750 BSP and VxWorks 3.5.1 (no + SENS or SENS 1.1 + SPR23938) and a minimum of 32 Mb memory. + +* PSS Core PPC860 processors, only erl_interface (too small main memory). + +Most PowerPC boards with FPU are expected to work, but will need to be +tested by OTP to be fully supported. + +The PPC603 build has been compiled with Wind River's `-mlongcall' +flag (SPR25893) to support arbitrary function calls across more +than 32 MB of memory. + +The PPC860 (PowerQuicc) has no FPU and requires a separate build. + +For Erlang to run, the Wind kernel has to be configured with a minimum +of these variables defined in config.h (or by the Tornado +configuration tool): + + INCLUDE_ANSI_ALL + INCLUDE_ENV_VARS + INCLUDE_EXC_HANDLING + INCLUDE_EXC_TASK + INCLUDE_FLOATING_POINT + INCLUDE_FORMATTED_IO + INCLUDE_IO_SYSTEM + INCLUDE_LOADER + INCLUDE_NETWORK + INCLUDE_NET_INIT + INCLUDE_NET_SHOW + INCLUDE_NET_SYM_TBL or INCLUDE_STANDALONE_SYM_TBL + INCLUDE_PIPES + INCLUDE_POSIX_FTRUNC + INCLUDE_RLOGIN or INCLUDE_TELNET (for pty's only) + INCLUDE_SELECT + INCLUDE_SEM_BINARY + INCLUDE_SEM_COUNTING + INCLUDE_SEM_MUTEX + INCLUDE_SHELL (*) + INCLUDE_SHOW_ROUTINES + INCLUDE_SIGNALS + INCLUDE_STARTUP_SCRIPT (*) + INCLUDE_STDIO + INCLUDE_SYM_TBL + INCLUDE_TASK_HOOKS + INCLUDE_TASK_VARS + INCLUDE_TTY_DEV + INCLUDE_UNLOADER + INCLUDE_NFS or INCLUDE_RAMDRV or INCLUDE_DOSFS (i.e. a file system, + possibly read-only) (**) + +(*) Needed for the example startup script, not actually needed in production if + erlang is set up by a c routine called from usrConfig.c. +(**) INCLUDE_NFS usually requires the NFS_USER_ID and NFS_GROUP_ID variables + to be set in config.h + +As an erlang system may open a lot of files, it is recommended to raise the +default NUM_FILES variable to something like 256 in config.h like this: + #ifdef NUM_FILES + #undef NUM_FILES + #endif + #define NUM_FILES 256 + +The SENS stack *has* to be of version 1.1 or higher, 1.0 is *not* +supported and will not work reliably. Upgrades as well as the patch +for SPR23938 can be found at www.wrs.com (i.e. WindSurf). Also, the +following constants in $WIND_BASE/target/h/netBufLib.h has to be +raised to a value of at least four times the default: + + NUM_NET_MBLKS + NUM_64 + NUM_128 + NUM_256 + NUM_512 + NUM_1024 + NUM_2048 + + NUM_SYS_64 + NUM_SYS_128 + NUM_SYS_256 + NUM_SYS_512 + +Use the show routines mbufShow and netStackSysPoolShow to verify that +these pools are not exhausted. + +Installation +------------ + +To install Erlang on a VxWorks card, the following knowledge is +expected: + +* VxWorks installation and configuration. + +* Network (TCP/IP) configuration. + +* Erlang basic operation and configuration. + +There is no specific install script for erlang on the VxWorks +platform. There is however an example VxWorks startup file named +erts-5.0.1/bin/erl_script.sam under the root of an unpacked +release. There may of course be other things to do in the start +script, like using the rdate program in the erlang distribution to get +a correct date and set the TIMEZONE variable. + +Please consult the "Embedded System" documentation for further +information on installation. + +Known Bugs and problems +----------------------- + +We have found the VxWorks/NFS client file system to be unreliable. +Important file operations like rename, ftruncate, cd and unlink +doesn't always work as expected. Therefore more complex file using +parts of OTP, like DETS and disk based mnesia tables cannot be used +reliably with NFS. Lowering the NFS cache size (global variable +nfsCacheSize) to 512 gives a more reliable NFS client, but to disk +base the mnesia tables over NFS is still not a good idea, especially +as disk based mnesia tables are not supported on VxWorks. Another +problem with VxWorks file systems is that the error codes they produce +are not consistent. We have worked around this problem by mapping the +codes to POSIX ones, by doing this we make the VxWorks Erlang platform +behave similarly to the UNIX and Windows implementations. + +The rename and ftruncate operations over NFS are emulated using +copying of files. This is mainly for our own test suites and it is not +recommended to use file:rename and/or file:ftruncate on NFS file +systems in production. + +Floating point operations is somewhat faulty. For instance, testing +floating point numbers for equality should be done with care. This is +actually not a bug, IEEE specifies no equality among floating point +numbers. + +Memory handling +--------------- + +Please read the erl_set_memory_block(3) manual page in the ERTS +documentation for information concerning memory handling in the erlang +emulator. Also please observe that reclaim.o has to be loaded and +reclaim_init() called before any other erlang routines are loaded and +started. If one wish to use the resource reclamation routines in other +programs, refer to the header file in `erts-5.0.1/include/reclaim.h'. +Including that file in your C source makes malloc/realloc/free and +open/fopen/socket/close etc be redefined to routines that makes the +memory and files be free'd/closed when the task exits. Still, +reclaim_init() *has* to be called before any program that uses this is +started. + +Using heart +----------- + +The default behavior of the heart object file that is part of the +distribution is that it reboots the target when the Erlang process +hasn't given it a heart beat in 60 seconds. The normal heart beat rate +is one beat per five seconds. This makes an effective "software +watchdog" but there is really no substitute for the real thing --- a +hardware watchdog. If you want to add a hardware watchdog to the +system please contact us for directions. If you want to disable the +reboot you may set the environment variable HEART_DONT_REBOOT (see the +example erlang start script, erl). Please note that if you DO want the +card to reboot you mustn't define HEART_DONT_REBOOT at all. E.g. to +disable heart reboot you may include the following line in the start +script (as is indeed the case with the example start script). + + putenv "HEART_DONT_REBOOT=1" + +A few words on writing port program and dynamically loaded drivers for VxWorks +------------------------------------------------------------------------------ + +VxWorks has one name-space for all symbols. This makes it harder to +write C programs whose global symbols doesn't interfere with each +other. It is a good rule to avoid all globally visible symbols that +are not absolutely necessary. Due to these facts we use the following +naming rules that are crucial to follow. (there are more issues +involved but the issues described here is a good beginning). + +Port programs must have a function with the same name as the object +file. E.g. if you have an object file named `port_test.o' it must +contain a globally visible function named `port_test'. This is the +function that will be called when you output data from Erlang to the +port. (The object file, in this example, should be named +`port_test.o', but `port_test' will also do). + +Also, in an embedded system, it is recommended to load the port +program into the system before the port program is used. This is to +avoid the real time degradation dynamical linking in runtime would +introduce. Use VxWorks command ld < "port_prg" to accomplish this. + +Dynamically linked drivers must have a function with the same name as +the object file with the added suffix `_init'. We recommend the use of +the macro DRIVER_INIT in `driver.h'. E.g. if you have an object file +named `echo_drv.eld' it must contain a globally visible function +`echo_drv_init'. (The object file, in this example, should be named +`echo_drv.eld' (`eld' is short for Erlang Loadable Driver), but +`echo_drv.o' and `echo_drv' will both also do). It is also very +important to initialize all unused function pointer in the +`driver_entry' struct to NULL (see example below). + +Example of dynamically linked driver +------------------------------------ + +#include <stdio.h> +#include "driver.h" + +static int erlang_port; +static long echo_start(); +static int echo_stop(), echo_read(); + +static struct driver_entry echo_driver_entry = { + null_func, + echo_start, + echo_stop, + echo_read, + null_func, + null_func, + "echo_drv", + null_func +}; + +int DRIVER_INIT(echo_drv)(void *handle) +{ + erlang_port = -1; + + echo_driver_entry.handle = handle; + return (int) &echo_driver_entry; +} + +static long echo_start(long port,char *buf) +{ + if (erlang_port != -1) { + return -1; + } + + erlang_port = port; + return port; +} + +static int echo_read(long port, char *buf, int count) +{ + return driver_output(erlang_port, buf, count); +} + +static int echo_stop() +{ + return erlang_port = -1; +} |