raspberry BSP: Maybe there is a bug in the linker file?

[Niteesh]

Shall I start writing a driver for raspberrypi3 PL011?


On Sat, Dec 21, 2019 at 8:40 PM Christian Mauderer <list at c-mauderer.de>
wrote:

> On 19/12/2019 15:05, Christian Mauderer wrote:
> > On 19/12/2019 14:27, Sebastian Huber wrote:
> >> On 19/12/2019 14:24, Christian Mauderer wrote:
> >>> Hello,
> >>>
> >>> triggered by the discussion regarding RTEMS on raspberrypi 3 I did some
> >>> tests. I haven't been able to start a RTEMS on my Pi 1 if I tried a
> >>> version after commit c5fd79cd4704a4270ba0114a1009ab8556f997c9 from
> >>> 29.07.2019. Right before it everything works as expected.
> >>>
> >>> The commit changes the memory locations. From what I understood, the
> >>> bootloader on a raspberry always jumps to address 0x8000 after loading
> >>> the application. So I'm not convinced that the change is correct.
> >>
> >> Is the 0x8000 a fixed address or you configure this in a boot image
> header?
> >>
> >
> >>From what I've seen the bootloader just uses a fixed address. All guides
> > that I've found just use objcopy to generate a binary from the elf files
> > without adding a header. For example a guide for RTEMS:
> >
> >
> >
> http://alanstechnotes.blogspot.com/2013/03/running-your-first-rtems-program-on.html
> >
> > A FreeRTOS port mentions this behavior explicitly in a comment in the
> > linker file:
> >
> >
> >
> https://github.com/jameswalmsley/RaspberryPi-FreeRTOS/blob/master/raspberrypi.ld#L17
> >
> > The "graphics processor" is no typo here. It seems the initialization is
> > really done by the graphics processor on the pi.
> > _______________________________________________
> > devel mailing list
> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel
> >
>
> I just found an option: It is possible to set a "kernel_address" in the
> config.txt:
>
>
> https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md
>
> So the start address can be changed and maybe the adaption to the linker
> file isn't necessary.
>
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