Re: [Qemu-arm] barebox on Canon A1100

[Sascha Hauer]

On Fri, Jan 04, 2019 at 01:56:41AM +0300, Antony Pavlov wrote:
> Hi Sascha!
> 
> I have some good news and some bad news.
> 
> First the good news.
> 
> Barebox was used for Day 18 of QEMU 2018 advent 
> (https://www.qemu-advent-calendar.org/2018/).
> 
> Here is a quote:
> 
>   > This is an image for QEMU's emulated Canon A1100 Arm machine:
>   > Play 2048 in the Barebox firmware environment.

Hey nice :)

> 
> The bad news.
> 
> Current master branch barebox for Canon A1100 does not work under qemu,
> barebox v2017.02.0 was used for qemu advent.
> 
> Thomas Huth reported the problem in the qemu-devel mailing
> list two months ago. Please see 
> https://www.mail-archive.com/address@hidden/msg571887.html
> for details.
> 
> The commit a43e2bbc468a71 breaks barebox for Canon A1100:
> 
>   > commit a43e2bbc468a71fb8825e8acafb7fac7ad7c6dad
>   > Author: Sascha Hauer <address@hidden>
>   > Date:   Wed Mar 7 10:04:07 2018 +0100
>   >
>   >    ARM: return positive offset in get_runtime_offset()
> 
> Any suggestion?

Yes, try again with a recent barebox. There was a bug in this commit that
should be fixed with the following:

| commit 0230365df6601cd561c9e3e368c96222076ec9f5
| Author: Sascha Hauer <address@hidden>
| Date:   Wed Dec 12 08:55:31 2018 +0100
| 
|     ARM: fix setup_c when runtime offset is != 0
|     
|     The runtime offset has to be added to the memcpy source address and
|     substracted from the return address. This should have been changed in
|     a43e2bbc46 which changed from returning the negative runtime offset
|     into changing the positive runtime offset. Instead a43e2bbc46 only
|     changed a zero substraction ("subs r4, r0, #0") into a zero addition
|     ("adds r4, r0, #0") which was used as a equal to zero test and changed
|     nothing. This part is reverted here.
|     
|     Fixes wrong copy / return locations when setup_c is called with
|     different runtime and link addresses.
|     
|     fixes: a43e2bbc46 ("ARM: return positive offset in get_runtime_offset()")
|     
|     Signed-off-by: Sascha Hauer <address@hidden>

Sascha

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