[PATCH 14/17] x86: coreboot: Document the memory map

[Bin Meng]

Hi Simon,

On Wed, Apr 7, 2021 at 12:33 PM Simon Glass <sjg at chromium.org> wrote:
>
> Add information about memory usage when U-Boot is started from coreboot.
> This is useful when debugging. Also, since coreboot takes a chunk of
> memory in the middle of SDRAM for use by PCI devices, it can help avoid
> overwriting this with a loaded kernel by accident.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  doc/board/coreboot/coreboot.rst | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/doc/board/coreboot/coreboot.rst b/doc/board/coreboot/coreboot.rst
> index 9c44c025a48..e791b7e39f0 100644
> --- a/doc/board/coreboot/coreboot.rst
> +++ b/doc/board/coreboot/coreboot.rst
> @@ -50,3 +50,22 @@ works by using a 32-bit SPL binary to switch to 64-bit for running U-Boot. It
>  can be useful for running UEFI applications, for example.
>
>  This has only been lightly tested.
> +
> +
> +Memory map
> +----------
> +
> +::

Can we use the reST table syntax for the following table?

> +
> +    ffffffff  Top of ROM (and last byte of 32-bit address space)
> +    7a9fd000  Typical top of memory available to U-Boot
> +              (use cbsysinfo to see where memory range 'table' starts)
> +    10000000  Memory reserved by coreboot for mapping PCI devices
> +              (typical size 2151000, includes framebuffer)
> +     1920000  CONFIG_SYS_CAR_ADDR, fake Cache-as-RAM memory, used during startup
> +     1110000  CONFIG_SYS_TEXT_BASE (start address of U-Boot code, before reloc)
> +      110000  CONFIG_BLOBLIST_ADDR (before being relocated)
> +      100000  CONFIG_PRE_CON_BUF_ADDR
> +       f0000  ACPI tables set up by U-Boot
> +              (typically redirects to 7ab10030 or similar)
> +         500  Location of coreboot sysinfo table, used during startup
> --

Regards,
Bin