Ethos Driver Backwards Compatibility (#19116)

Differential Revision: D102359186

Pull Request resolved: #19116

Author: gkrulce

backends/arm/runtime/EthosUBackend_Cortex_M.cpp

@@ -24,6 +24,24 @@ using executorch::runtime::BackendExecutionContext;
 using executorch::runtime::Error;
 using executorch::runtime::Span;
 
+// Compatibility hooks for multi-device driver / non-multi-device driver code
+// When multi-device driver code is available, these declarations are overridden
+extern "C" __attribute__((weak)) int ethosu_get_product_config_from_cop_data(
+    const void*,
+    const int,
+    uint32_t* product_out,
+    uint32_t* log2_macs_out) {
+  *product_out = 0;
+  *log2_macs_out = 0;
+  return 0;
+}
+
+extern "C" __attribute__((weak)) struct ethosu_driver* ethosu_reserve_driver_ex(
+    uint32_t,
+    uint32_t) {
+  return ethosu_reserve_driver();
+}
+
 namespace executorch {
 namespace backends {
 namespace arm {
@@ -48,12 +66,20 @@ Error platform_execute(
     int output_count,
     Span<executorch::runtime::EValue*> args,
     char* ethosu_scratch) {
+  // Parse product config from command stream to reserve the correct driver
+  uint32_t product, log2_macs;
+  if (ethosu_get_product_config_from_cop_data(
+          handles.cmd_data, handles.cmd_data_size, &product, &log2_macs) != 0) {
+    ET_LOG(Error, "Failed to parse product config from command stream");
+    return Error::InvalidProgram;
+  }
+
   // Allocate driver handle and synchronously invoke driver
   auto driver =
       std::unique_ptr<ethosu_driver, decltype(&ethosu_release_driver)>(
-          ethosu_reserve_driver(), ethosu_release_driver);
+          ethosu_reserve_driver_ex(product, log2_macs), ethosu_release_driver);
   if (driver == nullptr) {
-    ET_LOG(Error, "ethosu_reserve_driver failed");
+    ET_LOG(Error, "ethosu_reserve_driver_ex failed");
     return Error::InvalidState;
   }
 

backends/arm/runtime/targets.bzl

@@ -29,7 +29,7 @@ def define_common_targets():
             "//executorch/runtime/backend:interface",
             ":vela_bin_stream",
             "//executorch/runtime/core:core",
-            "fbsource//third-party/ethos-u-core-driver:core_driver",
+            "fbsource//third-party/ethos-u-core-driver:core_driver_headers_only",
         ],
     )
     runtime.cxx_library(