[U-Boot] [PATCH v2 07/29] riscv: add Kconfig entries for the code model

[Bin Meng]

Hi Lukas,

On Tue, Oct 30, 2018 at 8:57 PM Lukas Auer
<lukas.auer at aisec.fraunhofer.de> wrote:
>
> RISC-V has two code models, medium low (medlow) and medium any (medany).
> Medlow limits addressable memory to a single 2 GiB range between the
> absolute addresses -2 GiB and +2 GiB. Medany limits addressable memory
> to any single 2 GiB address range.
> By default, medlow is selected on 32-bit systems and medany on 64-bit
> systems. This matches the configuration in Linux.
>
> The -mcmodel compiler flag is selected according to the Kconfig
> configuration.
>
> Signed-off-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>
> ---
>
> Changes in v2:
> - Change ISA string construction, as suggested by Bin Meng
>
>  arch/riscv/Kconfig  | 19 +++++++++++++++++++
>  arch/riscv/Makefile |  9 ++++++++-
>  2 files changed, 27 insertions(+), 1 deletion(-)
>

I had a further look at this, and I suspect we should stick to medlow
for U-Boot, even for 64-bit. As U-Boot will be only running within the
low 4GB memory space even for 64-bit. Adding medany seems unnecessary.

Regards,
Bin