[examples] Modify DFU update to add skip logic

For htools dfu, we seek to add some type of logic to skip an update.
With the opentitan get version, we can compare the versions and make the
decision to proceed or return with no actions.

Signed-off-by: Ellis Sarza-Nguyen <sarzanguyen@google.com>

Author: esnguyen

examples/htool_dfu.c

@@ -14,13 +14,35 @@
 #include "htool.h"
 #include "htool_cmd.h"
 #include "protocol/dfu_hostcmd.h"
+#include "protocol/opentitan_version.h"
+
+void process_image(struct libhoth_device* dev, const uint8_t* image, struct opentitan_image_version* rom_ext, struct opentitan_image_version* app, struct opentitan_get_version_resp * resp ) {
+
+  // Extract the offset that contains the ROM_EXT version information
+  uint32_t offset = (image[OPENTITAN_OFFSET_HEADER_DATA] | image[OPENTITAN_OFFSET_HEADER_DATA + 1] << 8 | image[OPENTITAN_OFFSET_HEADER_DATA + 2] << 16 | image[OPENTITAN_OFFSET_HEADER_DATA + 3] << 24);
+  rom_ext->major = image[offset + OPENTITAN_OFFSET_VERSION_MAJOR] | image[offset + OPENTITAN_OFFSET_VERSION_MAJOR + 1] << 8 | image[offset + OPENTITAN_OFFSET_VERSION_MAJOR + 2] << 16 | image[offset + OPENTITAN_OFFSET_VERSION_MAJOR + 3] << 24;
+  rom_ext->minor = image[offset + OPENTITAN_OFFSET_VERSION_MINOR] | image[offset + OPENTITAN_OFFSET_VERSION_MINOR + 1] << 8 | image[offset + OPENTITAN_OFFSET_VERSION_MINOR + 2] << 16 | image[offset + OPENTITAN_OFFSET_VERSION_MINOR + 3] << 24;
+
+  // Extract the offset that contains the APP version information
+  uint32_t offset_app = offset + 65536;
+  app->major = image[offset_app + OPENTITAN_OFFSET_VERSION_MAJOR] | image[offset_app + OPENTITAN_OFFSET_VERSION_MAJOR + 1] << 8 | image[offset_app + OPENTITAN_OFFSET_VERSION_MAJOR + 2] << 16 | image[offset_app + OPENTITAN_OFFSET_VERSION_MAJOR + 3] << 24;
+  app->minor = image[offset_app + OPENTITAN_OFFSET_VERSION_MINOR] | image[offset_app + OPENTITAN_OFFSET_VERSION_MINOR + 1] << 8 | image[offset_app + OPENTITAN_OFFSET_VERSION_MINOR + 2] << 16 | image[offset_app + OPENTITAN_OFFSET_VERSION_MINOR + 3] << 24;
+
+  // Get the current version of the device
+  libhoth_opentitan_version(dev, resp);
+
+}
 
 int htool_dfu_update(const struct htool_invocation* inv) {
   struct libhoth_device* dev = htool_libhoth_device();
   if (!dev) {
     return -1;
   }
 
+  struct opentitan_image_version rom_ext = {0};
+  struct opentitan_image_version app = {0};
+  struct opentitan_get_version_resp resp = {0};
+
   uint32_t complete_flags = 0;
   const char* reset_arg;
   if (htool_get_param_string(inv, "reset", &reset_arg)) {
@@ -68,25 +90,46 @@ int htool_dfu_update(const struct htool_invocation* inv) {
   if (image == MAP_FAILED) {
     fprintf(stderr, "mmap error: %s\n", strerror(errno));
     goto cleanup;
-  }
+  } 
+
+  process_image(dev, image, &rom_ext, &app, &resp);
 
-  if (libhoth_dfu_update(dev, image, statbuf.st_size, complete_flags) != 0) {
-    fprintf(stderr, "DFU update failed.\n");
-    goto cleanup2;
+  // Process the current boot slot
+  uint32_t boot_slot = resp.primary_bl0_slot == kOpentitanBootSlotA ? 0 : 1;
+
+  if(resp.rom_ext.slots[boot_slot].major != rom_ext.major || resp.rom_ext.slots[boot_slot].minor != rom_ext.minor || resp.app.slots[boot_slot].major != app.major || resp.app.slots[boot_slot].minor != app.minor) {
+    printf("Version mismatch\n");
+    // Perform the DFU update 2x to ensure the device is updated for both partitions
+    for(int i = 0; i < 2; i++) {
+      if (libhoth_dfu_update(dev, image, statbuf.st_size, complete_flags) != 0) {
+        fprintf(stderr, "DFU update failed.\n");
+        goto cleanup2;
+      }
+    }
+  }
+  else {
+    printf("Version match\n");
+    return 0;
   }
+
   retval = 0;
 
   int ret;
-cleanup2:
-  ret = munmap(image, statbuf.st_size);
-  if (ret != 0) {
-    fprintf(stderr, "munmap error: %d\n", ret);
-  }
 
-cleanup:
-  ret = close(fd);
-  if (ret != 0) {
-    fprintf(stderr, "close error: %d\n", ret);
-  }
+  goto cleanup2;
+  goto cleanup;
+
+  cleanup2:
+    ret = munmap(image, statbuf.st_size);
+    if (ret != 0) {
+      fprintf(stderr, "munmap error: %d\n", ret);
+    }
+
+
+  cleanup:
+    ret = close(fd);
+    if (ret != 0) {
+      fprintf(stderr, "close error: %d\n", ret);
+    }
   return retval;
-}
+}

examples/htool_dfu.h

@@ -15,13 +15,21 @@
 #ifndef LIBHOTH_EXAMPLES_HTOOL_DFU_H_
 #define LIBHOTH_EXAMPLES_HTOOL_DFU_H_
 
+#include "protocol/opentitan_version.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 struct htool_invocation;
 
 int htool_dfu_update(const struct htool_invocation* inv);
+void process_image( struct libhoth_device* dev, 
+                    const uint8_t* image,
+                    struct opentitan_image_version* rom_ext, 
+                    struct opentitan_image_version* app,
+                    struct opentitan_get_version_resp * resp );
+
 
 #ifdef __cplusplus
 }

protocol/opentitan_version.h

@@ -30,6 +30,12 @@ extern "C" {
 #define OPENTITAN_VERSION_HASH_SIZE 8
 #define OPENTITAN_NUM_SLOTS 2
 
+#define OPENTITAN_OFFSET_HEADER_DATA 36
+#define OPENTITAN_OFFSET_VERSION_MAJOR 836
+#define OPENTITAN_OFFSET_VERSION_MINOR 840
+#define OPENTITAN_OFFSET_VERSION_SECURITY 844
+#define OPENTITAN_OFFSET_TIMESTAMP 848
+
 typedef uint32_t opentitan_boot_slot_t;
 
 enum opentitan_boot_slot {