Date: Sat, 27 Sep 2014 13:43:55 -0700 From: Russell Haley <russ.haley@gmail.com> To: Tim Kientzle <tim@kientzle.com>, Rui Paulo <rpaulo@me.com> Cc: freebsd-arm@freebsd.org Subject: Re: Digi CCWMX53 Message-ID: <CABx9NuQGTpw_aNB%2Be2NO6_SPkF0JqiJeucRRGrhvfY5uT9iGzA@mail.gmail.com> In-Reply-To: <CABx9NuTRwBHLYJb1NP3=X6TuLcbZ_KsUBsdNVq3GX2ffRs1_hA@mail.gmail.com> References: <CABx9NuQr%2BdEb_yj3ypEe6Sb_qPY%2BqP74n0x1K5=_K6Zoio2vkw@mail.gmail.com> <A4CEAFC3-446E-4D14-8F3B-1CDC92C65829@kientzle.com> <CABx9NuTRwBHLYJb1NP3=X6TuLcbZ_KsUBsdNVq3GX2ffRs1_hA@mail.gmail.com>
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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@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@kientzle.com> wrote: > >> >> On Sep 26, 2014, at 10:38 PM, Russell Haley <russ.haley@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 >> >> >
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