Beaglebone help needed

Wed Mar 6 20:17:44 UTC 2019

On 7/3/19 3:52 am, Christian Mauderer wrote:
> Am 06.03.19 um 12:11 schrieb Chris Johns:
>> On 6/3/19 6:07 pm, Sarvesh Patkar wrote:
>>> Hey everyone,
>>>
>>> I went through the quick start guide and could build the Hello World for the
>>> sparc/erc32 target.
>>>
>>> I would like to contribute to RTEMS in adding functionality and maybe, writing
>>> BSPs for some development boards that I have. I started with Beaglebone Black.
>>
>> Welcome and this sounds great.
> 
> Note that the Beagle Bone Black is already quite well supported (except
> for the outdated documentation). Of course there is always room to
> improvement.

Yes and this is really nice. I like this board and the BSP so thank you for your
efforts here.

> 
>>
>>> There are a few questions that I have as follows.
>>>
>>>  1. There is a build set called beagle.bset that is defined in Ben Gras's Github
>>>     repository (https://github.com/bengras/rtems-source-builder/tree/beagle),
>>>     that hasn't been merged into the main rtems-source-builder git repository.
>>>     Is there a way to know if that will happen? 
>>
>> It could be if it is updated so it can be merged to master.>
> The build set compiles some additional tools and libraries. The tools
> are useful but not necessary to create bootable images. Most likely Ben
> used the libraries for some project.
>

I was looking at the special build of qemu which has extra things needed to
support the BBB. Ben has done a lot of work with the SoC and board. Maybe that
could be refactored out.

> Please note that I write the following without detailed tests from some
> notes / scripts. So there might could be typos or some problems with the
> order.

The following is looking like a bbb section for the User Manual :)

Chris

> 
> For a BBB with an up to date U-Boot (newer than about 2017) on your
> Beagle you don't have to use these tools. The U-Boot that is provided by
> the official BBB images now looks for a uEnv.txt on your SD and executes
> that if it is available.
> 
> You can build the toolchain and system the normal way like any other
> RTEMS tool chain (like you did for erc32) from master. Beneath that you
> need a mkimage from U-Boot. Any recent version should do. As soon as you
> have your executable you need the following steps:
> 
> ----
> arm-rtems5-objcopy app.exe -O binary app.bin
> 
> gzip -9 app.bin
> 
> mkimage -A arm -O linux -T kernel -a 0x80000000 -e 0x80000000 -n RTEMS
> -d app.bin.gz rtems-app.img
> ----
> 
> You can then copy the rtems-app.img to the root directory of a
> FAT-formatted SD card. Put a uEnv.txt with the following content beneath
> it (the line with boot=... and the following are one - my mail client
> just breaks it):
> 
> ----
> setenv bootdelay 5
> uenvcmd=run boot
> boot=fatload mmc 0 0x80800000 rtems-app.img ; fatload mmc 0 0x88000000
> am335x-boneblack.dtb ; bootm 0x80800000 - 0x88000000
> ----
> 
> The last file that you need is a device tree file
> (am335x-boneblack.dtb). The simplest way to get that is to copy it from
> a Linux or FreeBSD image for the BBB. Copy it together with the other
> files to the root of the disk.
> 
> A disk that is prepared in that way should boot the RTEMS application if
> you put it in your BBB.
> 
> Like I said: I mostly wrote that down from head / scripts. I should
> update the README of the Beagle BSP sometimes but I haven't managed to
> bring myself to do it yet.
> 
> In the last two years, I have used some hacked together scripts to build
> a development environment that I used to test GSoC code. Basically it
> builds the same tools that Bens repo would build. It isn't integrated as
> nicely into RSB but it worked for me. The repo isn't totally up to date
> (last updated to RTEMS master on last Chrismas) but it should still
> work. If it helps you, you can find the scripts here:
> 
>     https://gitlab.com/c-mauderer/rtems-bbb
> 
> There is also a WiFi-Sample application in the repo that uses quite a
> lot of the hardware.
> 
> Best regards
> 
> Christian
> 
>>
>>>  2. The instructions given in the blog link mentioned on the
>>>     ticket https://devel.rtems.org/ticket/2891 do not seem to work because the
>>>     link for fetching the mpc library is broken/wrong. (I corrected the link
>>>     locally and the sb-set-builder seems to go beyond that error) I think this
>>>     change was made already in all branches in the official repository but not
>>>     Ben's. I see another error while running sb-set-builder during compilation
>>>     of ubsan.c (gcc-6.3.0) as follows. Is there a patch for this that I can
>>>     apply to fix my local clone of the rsb ?
>>
>> Are you using the master version of the RSB from git.rtems.org?
>>
>> Chris
>>
>>>
>>> ../../gcc-6.3.0/gcc/ubsan.c: In function 'bool ubsan_use_new_style_p(location_t)':
>>> ../../gcc-6.3.0/gcc/ubsan.c:1474:23: error: ISO C++ forbids comparison between
>>> pointer and integer [-fpermissive]
>>>        || xloc.file == '\0' || xloc.file[0] == '\xff'
>>>
>>> Any help in this matter is highly appreciated. If not the Beaglebone black, I
>>> have some ARM Cortex-M boards that I would like to work towards.
>>>
>>> Thank you for the help.
>>>
>>> Regards,
>>> Sarvesh
>>>
>>> _______________________________________________
>>> users mailing list
>>> users at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/users
>>>
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>>
> 