Verify data after writing

diff --git a/src/drivers/nvs/nvs.c b/src/drivers/nvs/nvs.c
index a566cdf..44b56f6 100644 (file)
--- a/src/drivers/nvs/nvs.c
+++ b/src/drivers/nvs/nvs.c
@@ -17,6 +17,8 @@
  */
 
 #include <stdint.h>
+#include <string.h>
+#include <errno.h>
 #include <assert.h>
 #include <gpxe/nvs.h>
 
@@ -69,6 +71,34 @@ int nvs_read ( struct nvs_device *nvs, unsigned int address,
        return 0;
 }
 
+/**
+ * Verify content of non-volatile storage device
+ *
+ * @v nvs              NVS device
+ * @v address          Address from which to read
+ * @v data             Data to compare against
+ * @v len              Length of data buffer
+ * @ret rc             Return status code
+ */
+static int nvs_verify ( struct nvs_device *nvs, unsigned int address,
+                       const void *data, size_t len ) {
+       uint8_t read_data[len];
+       int rc;
+
+       /* Read data into temporary buffer */
+       if ( ( rc = nvs_read ( nvs, address, read_data, len ) ) != 0 )
+               return rc;
+
+       /* Compare data */
+       if ( memcmp ( data, read_data, len ) != 0 ) {
+               DBG ( "NVS %p verification failed at %#04x+%d\n",
+                     nvs, address, len );
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 /**
  * Write to non-volatile storage device
  *
@@ -99,10 +129,14 @@ int nvs_write ( struct nvs_device *nvs, unsigned int address,
                if ( frag_len > len )
                        frag_len = len;
 
-               /* Read this portion of the buffer from the device */
+               /* Write this portion of the buffer to the device */
                if ( ( rc = nvs->write ( nvs, address, data, frag_len ) ) != 0)
                        return rc;
 
+               /* Read back and verify data */
+               if ( ( rc = nvs_verify ( nvs, address, data, frag_len ) ) != 0)
+                       return rc;
+
                /* Update parameters */
                data += frag_len;
                address += ( frag_len >> nvs->word_len_log2 );