Re: [Qemu-arm] [RFC] target-arm: fix semihosting ram base issue

[Tsung-Han Lin]

2016-06-17 17:43 GMT+09:00 Peter Maydell <address@hidden>:

On 17 June 2016 at 03:37, Tsung-Han Lin <address@hidden> wrote:
> Hi, I made some changes to TRY TO fix the ARM semihosting issue in
> SYS_HEAPINFO handling.
> This problem has been bothering me for quite a while.
>
> A new global variable 'main_ram_base' is added while a new memory
> API, memory_region_add_subregion_main, is also provided to let
> SoC/board creator to initialize this variable.
> I am not sure if this is a good idea (to add a new API)
> or maybe we just let SoC/board creator to simply
> set 'main_ram_base' in their 'xxx_realize' functions?
>
> As for Cortex-M series, 'main_ram_base' is set during cpu initialization.
> A64 semihosting handling is also added and use zynqmp as an example.

Could you explain what the bug is you're trying to fix, please?

I was trying to use semihosting on different configs.

Each of them have different ram base values, which is assumed to be 0x0 in qemu.

However, this may not be true for every SoC/boards.

(e.g., Cortex-M's ram addr is started on 0x20000000)

https://lists.gnu.org/archive/html/qemu-devel/2012-08/msg04641.html

So in order to use semihosting in different configs,

I have to change ram base value every time which is a bit inconvenience.

Also I added semihosting support for ARMv8 devices.

I am not sure my changes is legit or not and need some advices/comments from you all.

Thanks.

 

thanks
-- PMM

--

Tsung-Han "Johnny" Lin

Page: http://tsunghanlin.github.com/
Email: address@hidden