Allocate Custom Address to shared_dram

[msuthar25]

[sebraa]

On the host, you choose the address at allocation time. The default linker scripts use the lower 16 MB of DRAM for the C library, and declare the upper 16 MB as a section "shared_dram". All e_read()/e_write() offsets are relative to the address you allocated in the beginning.

On the other hand, nobody keeps you from accessing shared memory on the Epiphany through a pointer; on the Parallella board, the shared_dram section is at 0x8f000000 - if you allocate with an offset of 0x01000000, you need to use the offset 0x0. Write to 0x8f004000 on the Epiphany, and you need to e_read from 0x4000 (given the same allocation).

[msuthar25]