[RTEMS Project] #4623: Add RSB for LLVM targeting RTEMS

[RTEMS trac]

#4623: Add RSB for LLVM targeting RTEMS
-------------------------+-------------------------------------------------
  Reporter:  Joel        |      Owner:  (none)
  Sherrill               |
      Type:              |     Status:  new
  enhancement            |
  Priority:  normal      |  Milestone:  Indefinite
 Component:  tool        |    Version:
  Severity:  normal      |   Keywords:  llvm, tools, gcc, llvm, ecosystem,
                         |  SoC, large
Blocked By:              |   Blocking:
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 LLVM support for RTEMS has been included in the tools shipped by Gaisler
 (e.g. their RCC). RTEMS itself should now have all modifications needed to
 not be tied to GCC. This project is to add an RSB recipe to build an LLVM
 toolchain.

 Information from Daniel Hellstrom:

   RCC-1.3 has not converted into using the RSB. However I believe we have
 upstreamed every change to the RTEMS kernel tree which was related to
 LLVM/Clang support for SPARC. The RCC-1.3 section 2.2.4 includes some
 information what is compiled with GCC in our LLVM toolchain:

    * https://www.gaisler.com/anonftp/rcc/rcc-1.3/1.3.1/rcc-1.3.1.pdf

    * https://www.gaisler.com/anonftp/rcc/rcc-1.3/1.3.1/sparc-
 rtems-5-llvm-8.0.0-1.3.1-linux.txz

   For NOEL-V/RISC-V we only provide GCC toolchain today.

 After building the tools with the RSB, those tools must be used to build
 at least one BSP from an architecture which is not currently supported by
 LLVM. ARM, RISC-V, or x86_64 are likely first architectures to consider
 with testing on a BSP which can run on a simulator. Test results are
 necessary for GCC (baseline) and LLVM (objective).

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Ticket URL: <http://devel.rtems.org/ticket/4623>
RTEMS Project <http://www.rtems.org/>
RTEMS Project