ColdFireNotes < U-Boot

---+ GNU Toolchain for m68k / !ColdFire

The kernel.org toolchains are currently adopted for development. Btw, at least for tested target mcf5307, both i686 and x86_64 kernel.org available toolchains have open issues.

--- Adopted toolchains

These toolchains has been tested building u-boot and running the generated binary on the target board.


|  *Toolchain gcc*  |  *binutils*  |  *host version*  |  *target cpu / board*  |  *compile warnings* |  *notes*               |
|  [[http://sysam.it/openzone/toolchains/m68k/sysam-toolchain-m68k-gcc-4.9.0.tar.xz gcc-4.9.0-nolibc]]  |  2.26  | x86_64  |  -m5307 / amcore  |  no  |  created with buildall script from kernel.org  |
|  [[http://sysam.it/openzone/toolchains/m68k/sysam-toolchain-m68k-gcc-5.2.0.tar.xz gcc-5.2.0-nolibc]]  |  2.26  | x86_64  |  -m5307 / amcore  |  no  |  created with buildall script from kernel.org  |

Note: we had issues building the toolchains with "--with-arch=cf" option, since compilation breaks:<br>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68082<br>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68467<br>
Without "--with-arch=cf", m68000 libgcc code is generated, breaking final binaries built with the toolchain when libgcc is used.<br>
<br>
Since gcc team seems to keep m68k issues in a very low priority, these toolchains have the libgcc.a, libgcov.a and multilibs copied from an old toolchain.<br>
If you experience any issue, use CONFIG_USE_PRIVATE_LIBGCC in your board config file.<br>
<br>
Other bare-metal toolchains could be used, but note they can produce additional compile-time warnings in some cases, and u-boot code shouldn't be changed to remove the warnings in this cases. %BR% %BR%

Please report any issue to angelo @ sysam.it

See here for more information about toolchain-specific warnings: %BR%
[[https://lkml.org/lkml/2014/12/15/110]] %BR%
[[http://lists.denx.de/pipermail/u-boot/2014-December/199446.html]] %BR% %BR%

The discussion on how to avoid these "argument type" warnings with all tooolchains is still in progress.

---+ ISA Revisions

As the Coldfire cpu evolved, some instruction set architecture revisions (note, not core revisions) has been issued,
starting from the first, ISA_A, adding some instructions increasing the revision. Instruction sets are upward compatible.%BR% %BR%
ISA_A: it is the original Coldfire instruction set architecture, very similar to the m68000 instruction set%BR%
ISA_B: added improved data movement instructions, byte- and word-sized compares%BR%
miscellaneous enhancements%BR%
ISA_C: added instructions for improved bit manipulation%BR% %BR%

Below you can find what ISA Revision correspond to a cpu model. 

| Core V. |  *CPU Model*  | *ISA_A* | *ISA_A+* | *ISA_B* | *ISA_C* |
|  1  | mcf51qe       | | | |   X   |
|  2  | mcf5202       |    X    | | | |
|  2  | mcf5204       |    X    | | | |
|  2  | mcf5202       |    X    | | | |
|  2  | mcf5204       |    X    | | | |
|  2  | mcf5206       |    X    | | | |
|  2  | mcf5208       | |  X  | | |
|  2  | mcf52274      | |  X  | | |
|  2  | mcf52277      | |  X  | | |
|  3  | mcf5307       |    X    | | | |
|  3  | mcf5329       |    X    | | | |
|  3  | mcf5373       |    X    | | | |
|  4  | mcf5407       | | |  X  | |
|  4  | mcf5470       | | |  X  | |
|  4  | mcf5471       | | |  X  | |
|  4  | mcf5472       | | |  X  | |
|  4  | mcf54450      | | | |  X  |
|  4  | mcf54451      | | | |  X  |
|  4  | mcf54452      | | | |  X  |
|  4  | mcf54453      | | | |  X  |
|  4  | mcf54454      | | | |  X  |
|  4  | mcf54455      | | | |  X  |
|  4  | mcf54450      | | | |  X  |
|  4  | mcf54451      | | | |  X  |
|  4  | mcf54452      | | | |  X  |
|  4  | mcf54453      | | | |  X  |
|  4  | mcf54454      | | | |  X  |
|  4  | mcf54455      | | | |  X  |
%BR%
Note that some obsolete model is possibly not reported in the table above.

---++ TODOs
   * See how to avoid "argument type" compiler warnings for all the toolchains.


-- Main.AngeloDureghello - 07 Jan 2015