[U-Boot] [PATCH 14/14] SECURE_BOOT: Enable IE (Key extention) Feature in Ls2085a & LS2088a

[Saksham Jain <saksham.jain@nxp.com>]

For validating images from uboot (Such as Kernel Image), either keys
from SoC fuses can be used or keys from a veriied table of public keys
can be used. The latter feature is called IE Key Extension Feature.

For earlier SoCs, BootROM used to verify IE Key Table and then write the
address of this table in a secure register (SCRATCHREG). But in LS2088 and
LS2085, no such secure registers are available. Hence IE Table is left to be
verified by Uboot.

The new procedure is to first verify IE table using Keys stored in fuses,
and then use the keys in this table to verify further images. So the steps
are:

1) Verify IE Table (If "IE Table Flag" set in any image
i.e. Verify IE Table only when any image needs IE Table's Key to be verified)
2) Install IE table. (To be used across verification of multiple images.
Stored in a static global structure.)
3) If IE flag enabled in header of any image, Use keys from IE table,
otherwise use keys tied up with SoC's fuses (SRK).

The address of IE Table HDR is fixed for NOR. In case of boot from other
devices, IE Table and it's Header needs to be copied to an XIP Memory.

Signed-off-by: Aneesh Bansal <aneesh.bansal@nxp.com>
Signed-off-by: Saksham Jain <saksham.jain@nxp.com>
---
 arch/arm/include/asm/fsl_secure_boot.h |   6 +-
 board/freescale/common/fsl_validate.c  | 111 ++++++++++++++++++++++++++++-----
 include/fsl_validate.h                 |  23 ++++++-
 3 files changed, 119 insertions(+), 21 deletions(-)

diff --git a/arch/arm/include/asm/fsl_secure_boot.h b/arch/arm/include/asm/fsl_secure_boot.h
index 2d61436..09605dd 100644
--- a/arch/arm/include/asm/fsl_secure_boot.h
+++ b/arch/arm/include/asm/fsl_secure_boot.h
@@ -41,11 +41,11 @@
  * in boot ROM of the SoC.
  * The feature is only applicable in case of NOR boot and is
  * not applicable in case of RAMBOOT (NAND, SD, SPI).
+ * For LS, this feature is available for all device if IE Table
+ * is copied to XIP memory
+ * Also, for LS, ISBC doesn't verify this table.
  */
-#ifndef CONFIG_ESBC_HDR_LS
-/* Current Key EXT feature not available in LS ESBC Header */
 #define CONFIG_FSL_ISBC_KEY_EXT
-#endif
 
 #endif
 
diff --git a/board/freescale/common/fsl_validate.c b/board/freescale/common/fsl_validate.c
index 95059c7..0620330 100644
--- a/board/freescale/common/fsl_validate.c
+++ b/board/freescale/common/fsl_validate.c
@@ -27,6 +27,8 @@
 #define CHECK_KEY_LEN(key_len)	(((key_len) == 2 * KEY_SIZE_BYTES / 4) || \
 				 ((key_len) == 2 * KEY_SIZE_BYTES / 2) || \
 				 ((key_len) == 2 * KEY_SIZE_BYTES))
+/* Global data structure */
+static struct fsl_secboot_glb *glb;
 
 /* This array contains DER value for SHA-256 */
 static const u8 hash_identifier[] = { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
@@ -60,7 +62,7 @@ self:
 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
 static u32 check_ie(struct fsl_secboot_img_priv *img)
 {
-	if (img->hdr.ie_flag)
+	if (img->hdr.ie_flag & IE_FLAG_MASK)
 		return 1;
 
 	return 0;
@@ -119,7 +121,8 @@ int get_csf_base_addr(u32 *csf_addr, u32 *flash_base_addr)
 }
 #endif
 
-static int get_ie_info_addr(u32 *ie_addr)
+#if !defined(CONFIG_ESBC_HDR_LS)
+static int get_ie_info_addr(uintptr_t *ie_addr)
 {
 	struct fsl_secboot_img_hdr *hdr;
 	struct fsl_secboot_sg_table *sg_tbl;
@@ -147,16 +150,17 @@ static int get_ie_info_addr(u32 *ie_addr)
 
 	/* IE Key Table is the first entry in the SG Table */
 #if defined(CONFIG_MPC85xx)
-	*ie_addr = (sg_tbl->src_addr & ~(CONFIG_SYS_PBI_FLASH_BASE)) +
-		   flash_base_addr;
+	*ie_addr = (uintptr_t)((sg_tbl->src_addr &
+			~(CONFIG_SYS_PBI_FLASH_BASE)) +
+			flash_base_addr);
 #else
-	*ie_addr = sg_tbl->src_addr;
+	*ie_addr = (uintptr_t)sg_tbl->src_addr;
 #endif
 
-	debug("IE Table address is %x\n", *ie_addr);
+	debug("IE Table address is %lx\n", *ie_addr);
 	return 0;
 }
-
+#endif /* CONFIG_ESBC_HDR_LS */
 #endif
 
 #ifdef CONFIG_KEY_REVOCATION
@@ -164,7 +168,10 @@ static int get_ie_info_addr(u32 *ie_addr)
 static u32 check_srk(struct fsl_secboot_img_priv *img)
 {
 #ifdef CONFIG_ESBC_HDR_LS
-	/* In LS, No SRK Flag as SRK is always present*/
+	/* In LS, No SRK Flag as SRK is always present if IE not present*/
+#if defined(CONFIG_FSL_ISBC_KEY_EXT)
+	return !check_ie(img);
+#endif
 	return 1;
 #else
 	if (img->hdr.len_kr.srk_table_flag & SRK_FLAG)
@@ -253,14 +260,61 @@ static u32 read_validate_single_key(struct fsl_secboot_img_priv *img)
 #endif /* CONFIG_ESBC_HDR_LS */
 
 #if defined(CONFIG_FSL_ISBC_KEY_EXT)
+
+#if defined(CONFIG_ESBC_HDR_LS)
+static void install_ie_tbl(uintptr_t ie_tbl_addr,
+		struct fsl_secboot_img_priv *img)
+{
+	/* Copy IE tbl to Global Data */
+	memcpy(&glb->ie_tbl, (u8 *)ie_tbl_addr, sizeof(struct ie_key_info));
+	img->ie_addr = (uintptr_t)&glb->ie_tbl;
+	glb->ie_addr = img->ie_addr;
+}
+#endif
+
 static u32 read_validate_ie_tbl(struct fsl_secboot_img_priv *img)
 {
 	struct fsl_secboot_img_hdr *hdr = &img->hdr;
 	u32 ie_key_len, ie_revoc_flag, ie_num;
 	struct ie_key_info *ie_info;
 
-	if (get_ie_info_addr(&img->ie_addr))
-		return ERROR_IE_TABLE_NOT_FOUND;
+/* For LS, IE Table is installed as a separate image.
+ * It is not verified by ISBC.
+ */
+	if (!img->ie_addr)
+#if defined(CONFIG_ESBC_HDR_LS)
+		/* Verify and Install IE Table */
+		debug("Verifying IE Table\n");
+
+		int ret;
+		ret = fsl_secboot_validate(IE_TABLE_HDR_ADR, NULL,
+			0);
+		if (ret) {
+			printf("IE Table Verification Failed\n");
+			return ret;
+		} else {
+			printf("IE Table Verified Successfully\n");
+			/* If the image is IE Table,
+			 * then install that IE Table for
+			 * future verification process.
+			 */
+			char *s = getenv("img_addr");
+
+			uintptr_t ie_tbl_addr =
+				(uintptr_t)simple_strtoull(s, NULL, 16);
+
+			install_ie_tbl(ie_tbl_addr, img);
+			/* Again overide the "img_addr" env variable to
+			 * point to addr of image being verified
+			 */
+			char buf[20];
+			sprintf(buf, "%lx", img->img_addr);
+			setenv("img_addr", buf);
+		}
+#else
+		if (get_ie_info_addr(&img->ie_addr))
+			return ERROR_IE_TABLE_NOT_FOUND;
+#endif
 	ie_info = (struct ie_key_info *)(uintptr_t)img->ie_addr;
 	if (ie_info->num_keys == 0 || ie_info->num_keys > 32)
 		return ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY;
@@ -815,6 +869,34 @@ static int calculate_cmp_img_sig(struct fsl_secboot_img_priv *img)
 	return 0;
 }
 
+/* Function to initialize img priv and global data structure
+ */
+static int secboot_init(struct fsl_secboot_img_priv **img_ptr)
+{
+	/* Init global data only once */
+	if (!glb) {
+		glb = malloc(sizeof(struct fsl_secboot_glb));
+		memset(glb, 0, sizeof(struct fsl_secboot_glb));
+
+	if (!glb)
+		return -ENOMEM;
+	}
+
+	*img_ptr = malloc(sizeof(struct fsl_secboot_img_priv));
+
+	struct fsl_secboot_img_priv *img = *img_ptr;
+
+	if (!img)
+		return -ENOMEM;
+	memset(img, 0, sizeof(struct fsl_secboot_img_priv));
+
+#if defined(CONFIG_FSL_ISBC_KEY_EXT)
+	if (glb->ie_addr)
+		img->ie_addr = glb->ie_addr;
+#endif
+	return 0;
+}
+
 int fsl_secboot_validate(uintptr_t haddr, char *arg_hash_str,
 			uintptr_t img_addr)
 {
@@ -859,12 +941,9 @@ int fsl_secboot_validate(uintptr_t haddr, char *arg_hash_str,
 		hash_cmd = 1;
 	}
 
-	img = malloc(sizeof(struct fsl_secboot_img_priv));
-
-	if (!img)
-		return -1;
-
-	memset(img, 0, sizeof(struct fsl_secboot_img_priv));
+	ret = secboot_init(&img);
+	if (ret)
+		return ret;
 
 	/* Update the information in Private Struct */
 	hdr = &img->hdr;
diff --git a/include/fsl_validate.h b/include/fsl_validate.h
index ff6f6b7..85673c8 100644
--- a/include/fsl_validate.h
+++ b/include/fsl_validate.h
@@ -40,8 +40,8 @@ struct fsl_secboot_img_hdr {
 		u8 num_srk;
 		u8 srk_sel;
 		u8 reserve;
-		u8 ie_flag;
 	} len_kr;
+	u8 ie_flag;
 
 	u32 uid_flag;
 
@@ -69,6 +69,10 @@ struct fsl_secboot_img_hdr {
 #define MAX_KEY_ENTRIES 8
 #endif
 
+#if defined(CONFIG_FSL_ISBC_KEY_EXT)
+#define IE_FLAG_MASK 0x1
+#define IE_TABLE_HDR_ADR 0x5839c0000
+#endif
 
 #else /* CONFIG_ESBC_HDR_LS */
 
@@ -150,6 +154,10 @@ struct fsl_secboot_img_hdr {
 #define MAX_KEY_ENTRIES 4
 #endif
 
+#if defined(CONFIG_FSL_ISBC_KEY_EXT)
+#define IE_FLAG_MASK 0xFFFFFFFF
+#endif
+
 #endif /* CONFIG_ESBC_HDR_LS */
 
 
@@ -202,6 +210,17 @@ struct fsl_secboot_sg_table {
 };
 #endif
 
+/* ESBC global structure.
+ * Data to be used across verification of different images.
+ * Stores follwoing Data:
+ * IE Table
+ */
+struct fsl_secboot_glb {
+#if defined(CONFIG_FSL_ISBC_KEY_EXT)
+	uintptr_t ie_addr;
+	struct ie_key_info ie_tbl;
+#endif
+};
 /*
  * ESBC private structure.
  * Private structure used by ESBC to store following fields
@@ -213,7 +232,7 @@ struct fsl_secboot_sg_table {
  */
 struct fsl_secboot_img_priv {
 	uint32_t hdr_location;
-	u32 ie_addr;
+	uintptr_t ie_addr;
 	u32 key_len;
 	struct fsl_secboot_img_hdr hdr;
 
-- 
1.8.1.4