rockchip: mkimage: add support for verify_header/print_header

The rockchip image generation was previously missing the ability to
verify the generated header (and dump the image-type) without having
to resort to hexdump or od. Experience in our testing has showed it
to be very easy to get the rkspi and rksd images mixed up and the
lab... so we add the necessary support to have dumpimage tell us
what image type we're dealing with.

This change set adds the verify_header and print_header capability
to the rksd/rkspi image drivers (through shared code in rkcommon).

As of now, we only support images fully that are not RC4-encoded for
the SPL payload (i.e. header1 and payload). For RC4-encoded payloads,
the outer header (header0) is checked, but no detection of whether
this is a SD/MMC or SPI formatted payload takes place.

The output of dumpsys now prints the image type (spl_hdr), whether it
is a SD/MMC or SPI image, and the (padded) size of the image:
  $ ./tools/dumpimage -l ./spl.img
  Image Type:   Rockchip RK33 (SD/MMC) boot image
                               ^^^^^^ SD/MMC vs. SPI indication
                         ^^^^ spl_hdr indicated by the image
  Data Size:    79872 bytes

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 118 insertions, 1 deletions

diff --git a/tools/rkcommon.c b/tools/rkcommon.c
index 8283a74..92c2ff4 100644
--- a/tools/rkcommon.c
+++ b/tools/rkcommon.c
@@ -2,6 +2,8 @@
  * (C) Copyright 2015 Google,  Inc
  * Written by Simon Glass <sjg@chromium.org>
  *
+ * (C) 2017 Theobroma Systems Design und Consulting GmbH
+ *
  * SPDX-License-Identifier:	GPL-2.0+
  *
  * Helper functions for Rockchip images
@@ -201,7 +203,7 @@ int rkcommon_set_header(void *buf, uint file_size,
 
 	rkcommon_set_header0(buf, file_size, params);
 
-	/* Set up the SPL name */
+	/* Set up the SPL name (i.e. copy spl_hdr over) */
 	memcpy(&hdr->magic, rkcommon_get_spl_hdr(params), RK_SPL_HDR_SIZE);
 
 	if (rkcommon_need_rc4_spl(params))
@@ -211,6 +213,121 @@ int rkcommon_set_header(void *buf, uint file_size,
 	return 0;
 }
 
+static inline unsigned rkcommon_offset_to_spi(unsigned offset)
+{
+	/*
+	 * While SD/MMC images use a flat addressing, SPI images are padded
+	 * to use the first 2K of every 4K sector only.
+	 */
+	return ((offset & ~0x7ff) << 1) + (offset & 0x7ff);
+}
+
+static inline unsigned rkcommon_spi_to_offset(unsigned offset)
+{
+	return ((offset & ~0x7ff) >> 1) + (offset & 0x7ff);
+}
+
+static int rkcommon_parse_header(const void *buf, struct header0_info *header0,
+				 struct spl_info **spl_info)
+{
+	unsigned hdr1_offset;
+	struct header1_info *hdr1_sdmmc, *hdr1_spi;
+	int i;
+
+	if (spl_info)
+		*spl_info = NULL;
+
+	/*
+	 * The first header (hdr0) is always RC4 encoded, so try to decrypt
+	 * with the well-known key.
+	 */
+	memcpy((void *)header0, buf, sizeof(struct header0_info));
+	rc4_encode((void *)header0, sizeof(struct header0_info), rc4_key);
+
+	if (header0->signature != RK_SIGNATURE)
+		return -EPROTO;
+
+	/* We don't support RC4 encoded image payloads here, yet... */
+	if (header0->disable_rc4 == 0)
+		return -ENOSYS;
+
+	hdr1_offset = header0->init_offset * RK_BLK_SIZE;
+	hdr1_sdmmc = (struct header1_info *)(buf + hdr1_offset);
+	hdr1_spi = (struct header1_info *)(buf +
+					   rkcommon_offset_to_spi(hdr1_offset));
+
+	for (i = 0; i < ARRAY_SIZE(spl_infos); i++) {
+		if (!memcmp(&hdr1_sdmmc->magic, spl_infos[i].spl_hdr, 4)) {
+			if (spl_info)
+				*spl_info = &spl_infos[i];
+			return IH_TYPE_RKSD;
+		} else if (!memcmp(&hdr1_spi->magic, spl_infos[i].spl_hdr, 4)) {
+			if (spl_info)
+				*spl_info = &spl_infos[i];
+			return IH_TYPE_RKSPI;
+		}
+	}
+
+	return -1;
+}
+
+int rkcommon_verify_header(unsigned char *buf, int size,
+			   struct image_tool_params *params)
+{
+	struct header0_info header0;
+	struct spl_info *img_spl_info, *spl_info;
+	int ret;
+
+	ret = rkcommon_parse_header(buf, &header0, &img_spl_info);
+
+	/* If this is the (unimplemented) RC4 case, then rewrite the result */
+	if (ret == -ENOSYS)
+		return 0;
+
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * If no 'imagename' is specified via the commandline (e.g. if this is
+	 * 'dumpimage -l' w/o any further constraints), we accept any spl_info.
+	 */
+	if (params->imagename == NULL)
+		return 0;
+
+	/* Match the 'imagename' against the 'spl_hdr' found */
+	spl_info = rkcommon_get_spl_info(params->imagename);
+	if (spl_info && img_spl_info)
+		return strcmp(spl_info->spl_hdr, img_spl_info->spl_hdr);
+
+	return -ENOENT;
+}
+
+void rkcommon_print_header(const void *buf)
+{
+	struct header0_info header0;
+	struct spl_info *spl_info;
+	uint8_t image_type;
+	int ret;
+
+	ret = rkcommon_parse_header(buf, &header0, &spl_info);
+
+	/* If this is the (unimplemented) RC4 case, then fail silently */
+	if (ret == -ENOSYS)
+		return;
+
+	if (ret < 0) {
+		fprintf(stderr, "Error: image verification failed\n");
+		return;
+	}
+
+	image_type = ret;
+
+	printf("Image Type:   Rockchip %s (%s) boot image\n",
+	       spl_info->spl_hdr,
+	       (image_type == IH_TYPE_RKSD) ? "SD/MMC" : "SPI");
+	printf("Data Size:    %d bytes\n", header0.init_size * RK_BLK_SIZE);
+}
+
 void rkcommon_rc4_encode_spl(void *buf, unsigned int offset, unsigned int size)
 {
 	unsigned int remaining = size;