[denali] Add a stub client for denali

sys/denali/client/denali_client.cpp

@@ -0,0 +1,21 @@
+#include "denali/denali_client.h"
+
+#include <mammoth/debug.h>
+
+#include "denali/denali.h"
+
+MappedMemoryRegion DenaliClient::ReadSectors(uint64_t device_id, uint64_t lba,
+                                             uint64_t num_sectors) {
+  DenaliRead read{
+      .device_id = device_id,
+      .lba = lba,
+      .size = num_sectors,
+  };
+  check(channel_.WriteStruct(&read));
+
+  DenaliReadResponse resp;
+  uint64_t mem_cap;
+  check(channel_.ReadStructAndCap(&resp, &mem_cap));
+
+  return MappedMemoryRegion::FromCapability(mem_cap);
+}