As long as the GNSS feature is not used, GNSS RAM can be used as general memory.
This memory is 640KByte total, which is lower performance than the application RAM.
It is possible to locate text, data and bss into GNSS RAM and to use as heap area.
When I try to set priorities in certain programs, such as init_priority(HIGH_PRIORITY), I've noticed that during linking, there's no guarantee that the programs will be compiled in the sequence I've specified based on priority. This has led to some runtime errors in my program.
I realized that in the ld file, when initializing dynamic arrays, there's no assurance of initializing init_array.* before init_array. This has resulted in runtime errors in the program. Consequently, I've rearranged the init_array.* in the ld file of NuttX to be placed before init_array and added a SORT operation to init_array.* to ensure accurate initialization based on priorities during linking.
Summary:
- In order to support the atomic instructions by ldrex/strex instruction
in NuttX SMP, the data or later sections are mapped to the system bus.
Impact:
- Bootloader for Spresense SDK 2.1.0 or later must be installed
- Loops per msec must be adjusted
- Physical address for DMA must be converted with CXD56_PHYSADDR
Testing:
- Will be tested with later commits
Signed-off-by: Kazuya Hioki <Kazuya.Hioki@sony.com>
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
