I change communication region base to 0x900000
at inmate.h :
And I reserve 0x900000 for communication region at each example demo file for test.
It is executed successfully. So I checked patched rtems whether it reserves 0x900000 for communication region.
but I cannot find that. Gedare Bloom said :
I believe RTEMS stays in real mode, and we do not have any MMU support
code in place. One thing to check is the "memory map" of the linked
executable in startup/linkcmds, which specifies how the ELF file is
loaded into memory. The mentioned address should be reserved for
something, or else it would possibly get assigned to another area and
you may have some data corruption problem.
I should check linkcmds to reserve communication region.