[PATCH 1/3] Docs: RISC-V Update rv64* BSPs to medany and 0x80000000 start address

[Hesham Almatary]

Ping (as this was sent over holidays).

On Fri, 23 Dec 2022 at 09:48, <heshamelmatary at gmail.com> wrote:
>
> From: Hesham Almatary <hesham.almatary at cl.cam.ac.uk>
>
> Closes #4775
> ---
>  user/bsps/bsps-riscv.rst | 27 ++++++++++++---------------
>  1 file changed, 12 insertions(+), 15 deletions(-)
>
> diff --git a/user/bsps/bsps-riscv.rst b/user/bsps/bsps-riscv.rst
> index 2ef8327..5269462 100644
> --- a/user/bsps/bsps-riscv.rst
> +++ b/user/bsps/bsps-riscv.rst
> @@ -8,7 +8,7 @@ riscv (RISC-V)
>  riscv
>  =====
>
> -This BSP offers 15 variants:
> +This BSP offers 12 variants:
>
>  * rv32i
>
> @@ -26,22 +26,20 @@ This BSP offers 15 variants:
>
>  * rv64imac
>
> -* rv64imac_medany
> -
>  * rv64imafd
>
> -* rv64imafd_medany
> -
>  * rv64imafdc
>
> -* rv64imafdc_medany
> -
>  * frdme310arty
>
>  * mpfs64imafdc
>
> -Each variant corresponds to a GCC multilib.  A particular variant reflects an
> -ISA with ABI and code model choice.
> +Each rv* variant corresponds to a GCC multilib.  A particular variant reflects an
> +ISA with ABI and code model choice. All rv64 BSPs have medany code model by
> +default, while rv32 BSPs are medlow. The reason is that RV32 medlow can access
> +the entire 32-bit address space, while RV64 medlow can only access addresses
> +below 0x80000000. With RV64 medany, it's possible to perform accesses above
> +0x80000000.
>
>  The BSP must be started im machine mode.
>
> @@ -94,8 +92,7 @@ configuration INI file. The ``waf`` defaults can be used to inspect the values.
>       by default).
>
>  ``RISCV_RAM_REGION_BEGIN``
> -     The begin of the RAM region for linker command file (default is 0x70000000
> -     for 64-bit with -mcmodel=medlow and 0x80000000 for all other).
> +     The begin of the RAM region for linker command file (default is 0x80000000).
>
>  ``RISCV_RAM_REGION_SIZE``
>       The size of the RAM region for linker command file (default 64MiB).
> @@ -145,13 +142,13 @@ QEMU
>  ----
>
>  All of the BSP variants that start with rv can be run on QEMU's virt machine.
> -For instance, to run the ``rv64imafdc_medany`` BSP with the following
> -"config.ini" file:
> +For instance, to run the ``rv64imafdc`` BSP with the following
> +"config.ini" file.
>
>  .. code-block:: none
> -    [riscv/rv64imafdc_medany]
> +    [riscv/rv64imafdc]
>
> -Run the following QEMU command:
> +Run the following QEMU command.
>
>  .. code-block:: shell
>      $ qemu-system-riscv64 -M virt -nographic -bios $RTEMS_EXE
> --
> 2.25.1
>