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>
Since we provide all our own library calls, the fortification from
glibc just gets in our way (which some distros enable by default).
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This is an initial implementation with all functions defined but not working.
The lds file is very simple since we can mostly rely on the linker defaults.
Signed-off-by: Simon Glass <sjg@chromium.org>
