[U-Boot] [PATCH] SPL: Add HAB image authentication to FIT

[Peng Fan]

From: Ye Li <ye.li at nxp.com>

Introduce two board level callback functions to FIT image loading process, and
a SPL_FIT_FOUND flag to differentiate FIT image or RAW image.

Implement functions in imx common SPL codes to call HAB function
to authenticate the FIT image. Generally, we have to sign multiple regions
in FIT image:
1. Sign FIT FDT data (configuration)
2. Sign FIT external data (Sub-images)

Because the CSF supports to sign multiple memory blocks, so that we can use one
signature to cover all regions in FIT image and only authenticate once.
The authentication should be done after the entire FIT image is loaded into
memory including all sub-images.
We use "-p" option to generate FIT image to reserve a space for FIT IVT
and FIT CSF, also this help to fix the offset of the external data (u-boot-nodtb.bin,
ATF, u-boot DTB).

The signed FIT image layout is as below:
--------------------------------------------------
|     |     |     |   |           |     |        |
| FIT | FIT | FIT |   | U-BOOT    | ATF | U-BOOT |
| FDT | IVT | CSF |   | nodtb.bin |     |   DTB  |
|     |     |     |   |           |     |        |
--------------------------------------------------

Signed-off-by: Ye Li <ye.li at nxp.com>
Reviewed-by: Peng Fan <peng.fan at nxp.com>
Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 arch/arm/mach-imx/spl.c | 44 ++++++++++++++++++++++++++++++++++++++------
 common/spl/spl_fit.c    | 21 +++++++++++++++++++--
 include/spl.h           |  1 +
 3 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index a20b30d154..6f0b5cdb4c 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -220,14 +220,46 @@ __weak void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 
 	debug("image entry point: 0x%lX\n", spl_image->entry_point);
 
-	/* HAB looks for the CSF at the end of the authenticated data therefore,
-	 * we need to subtract the size of the CSF from the actual filesize */
-	offset = spl_image->size - CONFIG_CSF_SIZE;
-	if (!imx_hab_authenticate_image(spl_image->load_addr,
-					offset + IVT_SIZE + CSF_PAD_SIZE,
-					offset)) {
+	if (spl_image->flags & SPL_FIT_FOUND) {
 		image_entry();
 	} else {
+		/*
+		 * HAB looks for the CSF at the end of the authenticated
+		 * data therefore, we need to subtract the size of the
+		 * CSF from the actual filesize
+		 */
+		offset = spl_image->size - CONFIG_CSF_SIZE;
+		if (!imx_hab_authenticate_image(spl_image->load_addr,
+						offset + IVT_SIZE +
+						CSF_PAD_SIZE, offset)) {
+			image_entry();
+		} else {
+			puts("spl: ERROR:  image authentication fail\n");
+			hang();
+		}
+	}
+}
+
+ulong board_spl_fit_size_align(ulong size)
+{
+	/*
+	 * HAB authenticate_image requests the IVT offset is
+	 * aligned to 0x1000
+	 */
+
+	size = ALIGN(size, 0x1000);
+	size += CONFIG_CSF_SIZE;
+
+	return size;
+}
+
+void board_spl_fit_post_load(ulong load_addr, size_t length)
+{
+	u32 offset = length - CONFIG_CSF_SIZE;
+
+	if (imx_hab_authenticate_image(load_addr,
+				       offset + IVT_SIZE + CSF_PAD_SIZE,
+				       offset)) {
 		puts("spl: ERROR:  image authentication unsuccessful\n");
 		hang();
 	}
diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index faf4ddbd1f..db436268cb 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -15,6 +15,15 @@
 #define CONFIG_SYS_BOOTM_LEN	(64 << 20)
 #endif
 
+__weak void board_spl_fit_post_load(ulong load_addr, size_t length)
+{
+}
+
+__weak ulong board_spl_fit_size_align(ulong size)
+{
+	return size;
+}
+
 /**
  * spl_fit_get_image_name(): By using the matching configuration subnode,
  * retrieve the name of an image, specified by a property name and an index
@@ -350,6 +359,7 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	 */
 	size = fdt_totalsize(fit);
 	size = (size + 3) & ~3;
+	size = board_spl_fit_size_align(size);
 	base_offset = (size + 3) & ~3;
 
 	/*
@@ -373,8 +383,9 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	fit = spl_get_load_buffer(-hsize, hsize);
 	sectors = get_aligned_image_size(info, size, 0);
 	count = info->read(info, sector, sectors, fit);
-	debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu\n",
-	      sector, sectors, fit, count);
+	debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu, size=0x%lx\n",
+	      sector, sectors, fit, count, size);
+
 	if (count == 0)
 		return -EIO;
 
@@ -510,5 +521,11 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 	if (spl_image->entry_point == FDT_ERROR || spl_image->entry_point == 0)
 		spl_image->entry_point = spl_image->load_addr;
 
+	spl_image->flags |= SPL_FIT_FOUND;
+
+#ifdef CONFIG_SECURE_BOOT
+	board_spl_fit_post_load((ulong)fit, size);
+#endif
+
 	return 0;
 }
diff --git a/include/spl.h b/include/spl.h
index 9a439f468b..5dd25ab611 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -77,6 +77,7 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 			struct spl_load_info *info, ulong sector, void *fdt);
 
 #define SPL_COPY_PAYLOAD_ONLY	1
+#define SPL_FIT_FOUND		2
 
 /* SPL common functions */
 void preloader_console_init(void);
-- 
2.14.1