CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
data is located at the end of the available space
(sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
- CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
+ GENERATED_GBL_DATA_SIZE), and the initial stack is just
below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
CONFIG_SYS_GBL_DATA_OFFSET) downward.