Bug fix in Ethos runtime backend (#9517)

Summary:

Cortex-M is 32-bit, so pointer type in the runtime backend is also 32-bit. If the address >= 0x80000000, direct cast to uint64_t treates it as signed integer and sign extends it to 0xFFFFFFFFXXXXXXXX, which causes address validity check in Ethos driver to fail. First cast it to unsigned type uintptr_t then cast to uint64_t avoids this issue.

Reviewed By: digantdesai

Differential Revision: D71658384

Author: limintang

backends/arm/runtime/EthosUBackend.cpp

@@ -10,6 +10,7 @@
  * ethos-u-core-driver for hardware interaction.
  */
 
+#include <cstdint>
 #include <cstring>
 #include <memory>
 
@@ -282,7 +283,10 @@ class EthosUBackend final : public ::executorch::runtime::BackendInterface {
     // constant weight data, then scratch (which contains input and output)
     // scratch is written above in this function.
     uint64_t bases[2] = {
-        (uint64_t)handles.weight_data, (uint64_t)handles.scratch_data};
+        static_cast<uint64_t>(
+            reinterpret_cast<uintptr_t>((handles.weight_data))),
+        static_cast<uint64_t>(
+            reinterpret_cast<uintptr_t>((handles.scratch_data)))};
     size_t bases_size[2] = {
         handles.weight_data_size, handles.scratch_data_size};
     int result = 0;