Upcoming RTEMS Patch Set Background

Joel Sherrill joel.sherrill@oarcorp.com
Thu Sep 6 13:09:00 GMT 2012


I am about to submit 4 patches for RTEMS. Three of these are
related to our effort to update our old FreeBSD TCP/IP stack
to something modern and bring along USB host support.  The
USB host support is already working and the TCP/IP is coming

The short version is that we compile the parts of FreeBSD kernel
we need on top of RTEMS. The separation of kernel and user
namespaces is lost. This results in battling naming conflicts
(e.g. they redefine the signature of malloc) and differences
between POSIX and BSD. Right now, we have ~360 kernel
C files building and USB mass storage works so this is pretty
far along.

Except for the cdefs patch which might turn out to be need to be
RTEMS specific, I believe the others impact only RTEMS conditional
paths or files.

+ cdefs_patch - May be too much for newlib. I think the
     current cdefs.h is derived from an old Linux version per
     the comment. If the modifications to the shared cdefs.h
     are unacceptable, we can put this cdefs.h in sys/rtems.

+ param_patch - mbuf size changes based on which version
     of the TCP/IP stack you are using. I expect this conditional
     to go away once we kill the old stack. But who knows how
     long that will take.

+ signal_patch - adds sigaltstack prototypes to sys/signal.h
     which means our signal headers are good enough for the
     FreeBSD code.

+ types_patch - adds v850 to rtems specific file. This has nothing
     to do with the FreeBSD work but I noticed it was missing.

So that's what is happening in the RTEMS world and where
these patches are coming from.

Joel Sherrill, Ph.D.             Director of Research&   Development
joel.sherrill@OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
     Support Available             (256) 722-9985

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