These models have 256 kByte RAM, but the upper 64 kByte are used as CCM data RAM accessible at 0x1000:0000. The access to 0x2003:xxxx leads to a hard fault.
The stm32mp157c has the particularity to not having flash memory but
only SRAM.
Thus a part of SRAM must be considered as a ROM to flash the firmware
into.
In case of the stm32mp157c, the RETRAM (64kB) is used as ROM and the
4 banks of SRAM (384kB) are used as RAM.
However, as ROM_LEN, RAM_LEN, ROM_START_ADDRESS, RAM_START_ADDRESS and
ROM_OFFSET could be overloaded by user, set them with "?=" operator.
If the ROM_START_ADDRESS and the RAM_START_ADDRESS are not set at the
end of that file, it is a classic stm32 MCU with flash, thus set this
variables with common memory addresses for stm32 MCU family:
ROM_START_ADDR ?= 0x08000000
RAM_START_ADDR ?= 0x20000000
Signed-off-by: Gilles DOFFE <gilles.doffe@savoirfairelinux.com>
