Info regarding development activity in RTEMS for ARM bsps/Raspberry pi

[Hesham Moustafa]

Hi Ritesh,

On Wed, Aug 20, 2014 at 5:37 PM, Ritesh Harjani
<ritesh.harjani at gmail.com> wrote:
> Hi Hesham,
>
> Thanks for the info.
>
> On Wed, Aug 20, 2014 at 3:10 PM, Hesham Moustafa <heshamelmatary at gmail.com>
> wrote:
>>
>> Hi Ritesh,
>>
>> On Wed, Aug 20, 2014 at 11:28 AM, Ritesh Harjani
>> <ritesh.harjani at gmail.com> wrote:
>> > Hi All,
>> >
>> > I have been following RTEMS from quite some time rather I would say my
>> > questions have been on & off from this community (although I haven't
>> > contributed anything yet). So, this mail is mainly regarding some help
>> > from
>> > the community members so that I can pitch in to contribute something to
>> > this
>> > community.
>> >
>> > Based on my knowledge I would like to start from ARM bsps/raspberry pi
>> > as I
>> > am seeing quite lot of development activity going on in these areas.
>> >
>> > If someone can guide me with the following activities it would be great:
>> >
>> > 1. I need to just start something, may be with a small patch (which
>> > should
>> > be related to the above mentioned area):
>> > Earlier I thought of starting with some driver development but without
>> > having basic knowledge of RTEMS file structure/other areas, I wasn't
>> > able to
>> > complete it.
>> >
>> > 2. Need to understand the boot flow and the code initialization routine
>> > which can give me an idea as to where all and what all drivers are
>> > present
>> > etc etc..
>> >
>> >
>> > Later may be I can think of porting/developing some driver for any ARM
>> > bsp.
>> >
>> >
>> > Background activity done till now:
>> >
>> > 1. Followed all the steps in Alan's Blog
>> >
>> > (http://alanstechnotes.blogspot.in/2013/03/running-your-first-rtems-program-on.html):
>> > I was able to run ticker.exe sample test on Raspberry pi. Although there
>> > are
>> > some doubts which I have asked below.
>> >
>> > 2. Ordered OpenOCD based JTAG board. Once this comes I will make this
>> > JTAG
>> > board start working.
>> >
>> >
>> > Queries:
>> > 1. Is by default raspberry pi MMU enabled and all the page table are
>> > setup
>> > ?(from HEAD of git://git.rtems.org/rtems.git)
>> >
>> > 2. I cannot see any libmmu tests which I think Hesham developed during
>> > GSOC
>> > 2013 ?
>> > Do we keep this into different git ?
>> >
>> Some of my project code has been merged (mainly low-level parts of
>> libmm implemented for Raspberry Pi). The other code is held in my old
>> github repo here https://github.com/heshamelmatary/rtems-gsoc2013
>
>
> Thanks for the info, but I was unable to find mmtest in your git repo too.
> I saw in here: testsuites/libtests/
>
Please switch to the low-level-libmm branch. You can find all my
GSoC'2013 work there.
https://github.com/heshamelmatary/rtems-gsoc2013/tree/low-level-libmm/testsuites/libtests
>>
>> > 3. With OpenOCD and gdb is it possible to see all the CP15 coprocessor
>> > registers on ARM ?
>> >
>> > 4. How was Hesham able to debug and see the MMU register settings(like
>> > SCTLR.MMU) during his work on GSoc 2013 libmmu development for raspberry
>> > pi
>> > ? Was it QEMU ?
>> >
>> I was using QEMU for debugging Xilinx Zynq BSP, as well as Realview.
>> For Raspberry Pi (worked on the HW board, no simulators), I just used
>> printf to print out the values of registers which I need to peek into.
>
>
> Ya, with print help I was able to get the values of control and aux control
> register.
> So, by default L1 and L2 caches are enabled, also MMU is enabled :)
>
> For reference:
> Control register: 0x2085117d
> Aux control register: 0x7
>
>>
>> >
>> >
>> > Please feel free to guide me through the work plan if anyone have in
>> > his/her
>> > mind for ARM bsps.
>> >
>> >
>> >
>> > Thanks
>> > Ritesh Harjani
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>
>