Very often a constant pointer is passed to this function, so we should
declare this, since map_to_sysmem() does not change the pointer.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add generic board support for sandbox. and remove the old board init code.
Select CONFIG_SYS_GENERIC_BOARD for sandbox now that this is supported.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
In many cases, pointers to memory are passed around, and these pointers
refer to U-Boot memory, not host memory. This in itself is not a
problem.
However, in a few places, we cast that pointer back to a ulong (being
a U-Boot memory address). It is possible to convert many of these cases
to avoid this. However there are data structures (e.g. struct
bootm_headers) which use pointers. We could with a lot of effort adjust
the structs and all code that uses them to use ulong instead of pointers.
This seems like an unacceptable cost, since our objective with sandbox
is to minimise the impact on U-Boot code while maximising the features
available to sandbox.
Therefore, create a map_to_sysmem() function which converts from a
pointer to a U-Boot address. This can be used sparingly when needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Sandbox doesn't actually provide U-Boot access to the machine's physical
memory. Instead it provides a RAM buffer of configurable size, and all
memory accesses are within that buffer. Sandbox memory starts at 0 and
is CONFIG_DRAM_SIZE bytes in size. Allowing access outside this buffer
might produce unpredictable results in the event of an error, and would
expose the host machine's memory architecture to the sandbox U-Boot.
Most U-Boot functions assume that they can just access memory at given
address. For sandbox this is not true.
Add a map_sysmem() call which converts a U-Boot address to a system
address. In most cases this is a NOP, but for sandbox it returns a
pointer to that memory inside the RAM buffer.
To get a U-Boot feature to work correctly within sandbox, you should call
map_sysmem() to get a pointer to the address, and then use that address for
any U-Boot memory accesses.
Signed-off-by: Simon Glass <sjg@chromium.org>
This adds required header files for the sandbox architecture, and a basic
description of what sandbox is (README.sandbox).
Signed-off-by: Simon Glass <sjg@chromium.org>
