VxWorks 6.0 and EPICS

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VxWorks 6.0 and EPICSa first look

• Ernest L. Williams Jr.
• 27 April 2005
• EPICS Collaboration Meeting _at_ SLAC

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Outline

• What is vxWorks 6.0?
• Maybe we will begin using the tools?
• Integration into the EPICS R3.14 build system.
• Running with EPICS, cool!!
• Issues/Concerns
• References

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What is vxWorks 6.0?

• An expensive new toy!!

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What is VxWorks 6.0?
New Features

• Kernel execution environment compatible with 5.5
• Real-time Process environment for user-mode code
• MMU-based memory protection
• Error detection and reporting facility
• Better POSIX compilance, esp. in RTPs
• dosFS improvements
• Transaction-based Reliable File System
• ROMFS Filesystem
• New and enhanced IPC facilities
• Shared library support
• Object ownership and resource reclaimation
• Kernel (target) shell enhancements
• New processor/device support
• Improved OS configuration and build facilities

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What is VxWorks 6.0 (Contd)
Supported Hardware/Host
Not good where is the 68K support --- Did WRS
pull a Redhat?
Architectures Intel, MIPS and PowerPC
Architecture Families Pentium ,2,3,4 MIPS 5Kx, tx49xx, bcm125x Freescale PowerPC 60x, PowerPC 7xx, PowerPC 74xx, PowerPC 82xx, PowerPC 52xx, PowerPC 85xx IBM PowerPC 405, PowerPC 44x
Hosts Windows 2000 professional Windows XP Solaris 2.8, 2.9 Red Hat Enterprise Workstation 3.0 --- Fedora Core 3 works great as well (but not supported) --- Red Hat Enterprise Workstation 4.0 will be supported in future releases
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What is VxWorks 6.0 (Contd)
Real-time Processes

• Real-time Processes (RTPs) are containers for
  user-mode applications.
• Each RTP has own copies of code, data, stacks,
  heap and resources.
• RTPs are not scheduled tasks within RTPs are.
• RTPs are launched from a fully-linked relocatable
  executable loaded from a file system (a la UNIX).

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What is VxWorks 6.0 (Contd)
Kernel Enhancements

• Object Management (private and public scope)
• ISR Objects
• Optimized mutex semaphore for processes
• Task preemption prevention in processes
  (taskRtpLock/Unlock)
• Priority-inheritance enhancement
• Configurable kernel work queue size

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What is VxWorks 6.0 (Contd)
Memory Management

• Non-executable stack pages (certain CPUs.)
• Stack overrun and underrun detection.
• NULL pointer dereference detection (certain
  CPUs.)
• Text segment write protection
• Heap and partition manager instrumentation
  (run-time checking)
• Kernel heap allocator improvements (best-fit vs.
  first-fit)
• User-space heap and partition allocators

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What is VxWorks 6.0 (Contd)
Error Detection and Reporting

• New error detection and reporting facility
• Persistent error logs
• Configurable behaviors on a task, process, and
  system level
• Exception handlers instrumented to log information

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What is VxWorks 6.0 (Contd)
File System

• Improved dosFs file system
• Safest-order writes of metadata and user data to
  minimize chances of corruption
• Optional cache write-through
• Support for O_SYNC flag on open() operations
• FIOSYNC ioctl fully flushes block device caches
• Support for Unicode file names
• Enhanced CHKDSK (FAT recovery, performance, etc.)
• TRFS lightweight journaling filesystem
• ROMFS read-only filesystem

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What is VxWorks 6.0 (Contd)
Kernel (Target) Shell

• C interpreter enhancements for process
  information
• Handles long long, short, float, signed, unsigned
  types
• Path completion (if filesystem supports it)
• New UNIX shell like interpreter
• Allows custom interpreters
• Multiple shell support
• Secure access (user id/password protection)
• Fault management support (EDR)
• VI or EMACS style command line editting
• C symbol handling enhancements

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New Tools WindRiver Work Bench

• Development environment revolves around ECLIPSE.
• A smart move by WindRiver
• We still like using the commandline but maybe we
  will begin to use some of the builtin tools that
  come bundled with Workbench
• Source Code Analyzer
• Debugger
• System Viewer
• Scope Tools
• Sergei and Tom use ECLIPSE so it must be good!

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EPICS Integration
Prepare vxWorks for EPICS

• BSP migration and flashing the IOC
• Simply re-compile the mv2100 BSP against vxWorks
  6.0
• If you want native support, then follow the BSP
  migration documenation.
• The mv5100 BSP has native support for vxWorks 6.0
• The idea of the project facility is not too bad
  when done via command line.
• Use WRS workbench CLI to add components
  recommended by Andrew Johnson.
• http//www.aps.anl.gov/epics/base/T20xConfig.html
• vxprj component add INCLUDE_POSIX_TIMERS
• The GUI folks can use the workbench IDE to do
  this as well.

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EPICS Integration
Lets build some vxWorks 6.0 targets

• We begin by adding/modifying the EPICS build
  environment to support building vxWorks 6.0
  targets.
• Supported cross targets at the SNS
• MVM2101 (vxWorks-mv2100_v6)
• MVME5110 (vxWorks-mv5100_v6)
• Changes to (EPICS_BASE)/configure/CONFIG_SITE
• Add our two new cross targets
• Changes to (EPICS_BASE)/configure/os
• Add ---- CONFIG_SITE.linux-x86.vxWorks-mv2100_v6
• Add ---- CONFIG.Common.vxWorks-mv2100_v6
• Add ---- CONFIG_SITE.linux-x86.vxWorks-mv5100_v6
• Add ---- CONFIG.Common.vxWorks-mv5100_v6
• Add ---- CONFIG.Common.vxWorksCommon_v6

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EPICS Integration
Heres what we do for the mv2100
CONFIG_SITE.linux-x86.vxWorks-mv2100_v6 VX_DIR_YES
/ade/vxWorks/6.0 CONFIG.Common.vxWorks-mv2100
_v6 include (CONFIG)/os/CONFIG.Common.vxWorksComm
on_v6 Vx GNU cross compiler suffix CMPLR_SUFFIX
ppc ARCH_CLASS ppc Architecture specific
build flags ARCH_DEP_CPPFLAGS
-DCPUPPC603 ARCH_DEP_CFLAGS -mcpu603
-mstrict-align -mlongcall
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EPICS Integration
Wow WRS has moved the headers around on us, hmmm.
CONFIG.Common.vxWorksCommon_v6 -----------------
--------------------------------- vxWorks
directory definitions Tornado directory
definitions GNU_TARGET_INCLUDE_DIR
(VX_DIR)/vxworks-6.0/target/h GNU_TARGET_INCLUDE_
DIR (VX_DIR)/vxworks-6.0/target/h/wrn/coreip G
NU_DIR (VX_DIR)/gnu/3.3.2-vxworks60/x86-linux2
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Running with EPICS R3.14.7

• EPICS is running in kernel space
• Checkout the DEMO
• Next Step --- How can EPICS use RTPs?

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Issues/Concerns

• WRS supplied patches to get around issues with
  the new target shell environment.
• WRS did a great job to supply patches
• Compiler problems introduced for C drivers
• Not too bad but thrashes our developers a bit
• Licensing Model can be a pain.
• Need to do some real performance testing

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Issues/Concerns

• Disadvantages
• Much too expensive
• WRS is incompetent on deployment of their own
  licensing schemes
• Subscription versus Perpetual
• Tries to use FlexLM (maybe WRS should ask the
  MathWorks how to do this, hmmm?)
• Unique User
• Node-Locked
• Floating

• Advantages
• WRS is still the current leader in the Real-Time
  OS space.
• Many vendors will give or sell vxWorks drivers.
  Most will just give away the driver in
  source/binary form.
• Technical Support is really much better. Really
  they are!!
• Network Stack is improved

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References

• Talk by WindRiver Systems (March 2005)
• http//www.aps.anl.gov/epics