Digi CCWMX53

[Russell Haley]

Tim,

I'm trying to build from head because the Digi configuration only seems to
exist there. Unfortunately the last couple of checkouts I've done haven't
built. Can you recommend a  good working revision or should I ask this on
the current mailing list?

On Sat, Sep 27, 2014 at 1:19 PM, Russell Haley <russ.haley at gmail.com> wrote:

> Tim,
>
> Thanks, that's clarified a large number of my hanging questions.
>
> I thought I had read that clang didn't support cross compiling arm for
> freebsd in 10. Is this true?
>
> I should have some more shortly!
>
> Russ
>
>
> On Sat, Sep 27, 2014 at 11:53 AM, Tim Kientzle <tim at kientzle.com> wrote:
>
>>
>> On Sep 26, 2014, at 10:38 PM, Russell Haley <russ.haley at gmail.com> wrote:
>>
>> > 1) Can anyone give me the correct u-boot enviroment variables or
>> reference
>> > to the u-boot process to boot the completed freebsd kernel.
>> Specifically on
>> > a CCWMX53 if possible, but I have linux references to port from. Where
>> > would I look for an example?
>>
>> There are two general approaches being used:
>>
>> 1) Have U-Boot load and boot the kernel directly.  This can sometimes be
>> done with an unmodified Linux U-Boot.
>>
>> 2) Have U-Boot load FreeBSDs scriptable 'ubldr' and have that load the
>> kernel.  This provides more flexibility in the boot process but usually
>> requires rebuilding U-Boot.  In particular, you'll need to:
>>    * Add CONFIG_CMD_ELF option to U-Boot so it can load `ubldr' which is
>> an ELF executable
>>    * Add CONFIG_CMD_API option to U-Boot so `ubldr' can access U-Boot's
>> drivers for hardware access (`ubldr' itself has to be compiled for each
>> board to adjust the load address but is otherwise completely generic).
>>    * Adjust the U-Boot startup scripts to set FDT environment variables
>> and load ubldr.  You can look at the U-Boot patches for various boards
>> supported by Crochet to see how this has been done elsewhere:
>>    github.com/kientlze/crochet-freebsd
>>
>>
>> > 2) Do I need to create a cross compiler? Reference 1 says yes, reference
>> > two says no. Help!
>>
>> In most cases, the FreeBSD build system will build a cross-compiler for
>> it's own use, so you generally don't need to install a cross compiler to
>> cross-build FreeBSD proper.  However, U-Boot is not part of FreeBSD so you
>> may need to install a separate cross-compiler to build that.
>>
>> >
>> > Ref.1 Build  a cross compiler
>> > https://wiki.freebsd.org/FreeBSD/arm/ArndaleBoard
>>
>> This is using a cross-compiler from ports to build U-Boot.  It uses the
>> FreeBSD build machinery to cross-build the FreeBSD kernel and world.  (When
>> you specify TARGET_ARCH, FreeBSD's 'buildworld' target will build and use a
>> suitable cross-compiler.  Also, 'buildkernel' will reuse the cross-compiler
>> built by 'buildworld', so you do not need 'kernel-toolchain' as long as you
>> 'buildworld' first.)
>>
>> >
>> > Ref 2. No cross compiler/ make toolchain
>> > https://wiki.freebsd.org/A_Brief_Guide_To_Cross_Compiling_FreeBSD
>>
>> This example only talks about building *world*, and the 'buildworld'
>> target builds the necessary cross-tools transparently.  In particular,
>> since it doesn't talk about building out-of-tree boot loaders such as
>> U-Boot, it does not need to talk about building/installing an explicit
>> cross-compiler.
>>
>> For cross-compilers, you have three options:
>>  * Ports.
>>  * After a successful buildworld, you can 'make TARGET=xyz ... buildenv'
>> to get a shell with suitable path settings to reuse the cross-tools from
>> the buildworld stage.  Use 'buildenvvar' to just get the environment for
>> use in scripts.
>>  * FreeBSD source has an 'xdev' target that builds and installs a set of
>> cross-tools.  In particular, it can install cross-versions of the same GCC
>> or clang used by the rest of FreeBSD.  This facility has changed a lot
>> recently, so ask if you need the current command line.
>>
>> Hope this clarifies things,
>>
>> Tim
>>
>>
>