Transcript VxWorks 6.0 and EPICS “a first look” Ernest L. Williams Jr.

VxWorks 6.0 and EPICS
“a first look”
Ernest L. Williams Jr.
27 April 2005
EPICS Collaboration Meeting @ SLAC
ICS – Software Engineering Group
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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
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Error detection and reporting facility

Better POSIX compilance, esp. in RTPs

dosFS improvements
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Transaction-based Reliable File System

ROMFS Filesystem

New and enhanced IPC facilities

Shared library support
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Object ownership and resource reclaimation

Kernel (target) shell enhancements
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New processor/device support

Improved OS configuration and build facilities
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What is VxWorks 6.0 (Cont’d)
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 (Cont’d)
Real-time Processes

Real-time Processes (RTPs) are containers for usermode 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 (Cont’d)
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 (Cont’d)
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 (Cont’d)
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 (Cont’d)
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 (Cont’d)
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 (ED&R)

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
Let’s 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
Add
Add
Add
Add
---- CONFIG_SITE.linux-x86.vxWorks-mv2100_v6
---- CONFIG.Common.vxWorks-mv2100_v6
---- CONFIG_SITE.linux-x86.vxWorks-mv5100_v6
---- CONFIG.Common.vxWorks-mv5100_v6
---- CONFIG.Common.vxWorksCommon_v6
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EPICS Integration
Here’s 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.vxWorksCommon_v6
# Vx GNU cross compiler suffix
CMPLR_SUFFIX = ppc
ARCH_CLASS = ppc
# Architecture specific build flags
ARCH_DEP_CPPFLAGS = -DCPU=PPC603
ARCH_DEP_CFLAGS = -mcpu=603 -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
GNU_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
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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
References

Talk by WindRiver Systems (March 2005)

http://www.aps.anl.gov/epics
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