diff --git a/tools/rkcommon.c b/tools/rkcommon.c
index 5568b73..9595858 100644
--- a/tools/rkcommon.c
+++ b/tools/rkcommon.c
@@ -200,9 +200,13 @@
 	}
 }
 
-void rkcommon_vrec_header(struct image_tool_params *params,
-			  struct image_type_params *tparams)
+int rkcommon_vrec_header(struct image_tool_params *params,
+			 struct image_type_params *tparams,
+			 unsigned int alignment)
 {
+	unsigned int  unpadded_size;
+	unsigned int  padded_size;
+
 	/*
 	 * The SPL image looks as follows:
 	 *
@@ -228,4 +232,17 @@
 	/* Allocate, clear and install the header */
 	tparams->hdr = malloc(tparams->header_size);
 	memset(tparams->hdr, 0, tparams->header_size);
+	tparams->header_size = tparams->header_size;
+
+	/*
+	 * If someone passed in 0 for the alignment, we'd better handle
+	 * it correctly...
+	 */
+	if (!alignment)
+		alignment = 1;
+
+	unpadded_size = tparams->header_size + params->file_size;
+	padded_size = ROUND(unpadded_size, alignment);
+
+	return padded_size - unpadded_size;
 }
diff --git a/tools/rkcommon.h b/tools/rkcommon.h
index cc161a6..a21321f 100644
--- a/tools/rkcommon.h
+++ b/tools/rkcommon.h
@@ -83,8 +83,14 @@
  * @params:     Pointer to the tool params structure
  * @tparams:    Pointer tot the image type structure (for setting
  *              the header and header_size)
+ * @alignment:  Alignment (a power of two) that the image should be
+ *              padded to (e.g. 512 if we want to align with SD/MMC
+ *              blocksizes or 2048 for the SPI format)
+ *
+ * @return bytes of padding required/added (does not include the header_size)
  */
-void rkcommon_vrec_header(struct image_tool_params *params,
-			  struct image_type_params *tparams);
+int rkcommon_vrec_header(struct image_tool_params *params,
+			 struct image_type_params *tparams,
+			 unsigned int alignment);
 
 #endif
diff --git a/tools/rksd.c b/tools/rksd.c
index ac8a67d..6dafedf 100644
--- a/tools/rksd.c
+++ b/tools/rksd.c
@@ -29,12 +29,20 @@
 	unsigned int size;
 	int ret;
 
+	printf("params->file_size %d\n", params->file_size);
+	printf("params->orig_file_size %d\n", params->orig_file_size);
+
+	/*
+	 * We need to calculate this using 'RK_SPL_HDR_START' and not using
+	 * 'tparams->header_size', as the additional byte inserted when
+	 * 'is_boot0' is true counts towards the payload.
+	 */
 	size = params->file_size - RK_SPL_HDR_START;
 	ret = rkcommon_set_header(buf, size, params);
 	if (ret) {
 		/* TODO(sjg@chromium.org): This method should return an error */
-		printf("Warning: SPL image is too large (size %#x) and will not boot\n",
-		       size);
+		printf("Warning: SPL image is too large (size %#x) and will "
+		       "not boot\n", size);
 	}
 }
 
@@ -51,18 +59,11 @@
 		return EXIT_FAILURE;
 }
 
-/* We pad the file out to a fixed size - this method returns that size */
 static int rksd_vrec_header(struct image_tool_params *params,
 			    struct image_type_params *tparams)
 {
-	int pad_size;
-
-	rkcommon_vrec_header(params, tparams);
-
-	pad_size = RK_SPL_HDR_START + rkcommon_get_spl_size(params);
-	debug("pad_size %x\n", pad_size);
-
-	return pad_size - params->file_size - tparams->header_size;
+	/* We don't add any additional padding after the end of the image */
+	return rkcommon_vrec_header(params, tparams, 1);
 }
 
 /*
diff --git a/tools/rkspi.c b/tools/rkspi.c
index 0a15229..87bd1a9 100644
--- a/tools/rkspi.c
+++ b/tools/rkspi.c
@@ -39,8 +39,8 @@
 	debug("size %x\n", size);
 	if (ret) {
 		/* TODO(sjg@chromium.org): This method should return an error */
-		printf("Warning: SPL image is too large (size %#x) and will not boot\n",
-		       size);
+		printf("Warning: SPL image is too large (size %#x) and will "
+		       "not boot\n", size);
 	}
 
 	/*
@@ -71,23 +71,36 @@
 		return EXIT_FAILURE;
 }
 
-/* We pad the file out to a fixed size - this method returns that size */
+/*
+ * The SPI payload needs to be padded out to make space for odd half-sector
+ * layout used in flash (i.e. only the first 2K of each 4K sector is used).
+ */
 static int rkspi_vrec_header(struct image_tool_params *params,
 			     struct image_type_params *tparams)
 {
-	int pad_size;
-
-	rkcommon_vrec_header(params, tparams);
-
-	pad_size = ROUND(rkcommon_get_spl_size(params), 0x800);
-	params->orig_file_size = pad_size;
+	int padding = rkcommon_vrec_header(params, tparams, 2048);
+	/*
+	 * The file size has not been adjusted at this point (our caller will
+	 * eventually add the header/padding to the file_size), so we need to
+	 * add up the header_size, file_size and padding ourselves.
+	 */
+	int padded_size = tparams->header_size + params->file_size + padding;
 
-	/* We will double the image size due to the SPI format */
-	pad_size += RK_SPL_HDR_START;
-	pad_size *= 2;
-	debug("pad_size %x\n", pad_size);
+	/*
+	 * We need to store the original file-size (i.e. before padding), as
+	 * imagetool does not set this during its adjustment of file_size.
+	 */
+	params->orig_file_size = padded_size;
 
-	return pad_size - params->file_size - tparams->header_size;
+	/*
+	 * Converting to the SPI format (i.e. splitting each 4K page into two
+	 * 2K subpages and then padding these 2K pages up to take a complete
+	 * 4K sector again) will will double the image size.
+	 *
+	 * Thus we return the padded_size as an additional padding requirement
+	 * (be sure to add this to the padding returned from the common code).
+	 */
+	return padded_size + padding;
 }
 
 /*