core: add chip-specific memory regions definition mechanism

When a chip has special/non-contiguous SRAM physical memory region,
rather than extending the generic linker file ad nauseam, define a
mechanism to declare a chip specific list of those regions.

To do so, a chip must declare the CONFIG_CHIP_MEMORY_REGIONS
configuration and have a memory_regions.inc with the list of regions.

The special-purpose preprocessed chip/<chip_name>/memory_regions.inc
file has one region declaration per line using the following macro:
REGION(name, attributes, start_address, size)

Each region will get a proper MEMORY entry and a section in the linker
file.
the __SECTION(region_name) helper is provided as a convenience to
declare variable in a specific region.

Note: those 'special' regions are NOT cleared at startup contrary to
.bss.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=b:67081508
TEST=on ZerbleBarn, along with the following CLs, run the firmware with
large arrays in special AHB memory regions.

Change-Id: I3f156ef6e5feb4a6a0b2ae2468bae8a20483f17c
Reviewed-on: https://chromium-review.googlesource.com/946368
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

0 files changed, 0 insertions, 0 deletions