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

[Christian Mauderer]

On 21/12/2019 19:26, Niteesh wrote:
> There is already a PL011 driver in the arm shared section. should we
> just import it?

If you say "import" and you mean "use" and not "copy": yes, that would
be great.

> 
> On Sat, Dec 21, 2019 at 10:46 PM Niteesh <gsnb.gn at gmail.com
> <mailto:gsnb.gn at gmail.com>> wrote:
> 
>     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 <mailto: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 <mailto: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.
>