futility: cmd_show uses only vboot 2.0 APIs

This removes the remaining vboot 1.0 API calls from cmd_show.

BUG=chromium:611535
BRANCH=none
TEST=make runtests

Change-Id: I03c4260aa034100efbbea1005367cd85dfff273d
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/350173
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

3 files changed, 65 insertions, 7 deletions

diff --git a/firmware/lib20/include/vb2_common.h b/firmware/lib20/include/vb2_common.h
index 0ab89cab..536fbbb0 100644
--- a/firmware/lib20/include/vb2_common.h
+++ b/firmware/lib20/include/vb2_common.h
@@ -204,4 +204,26 @@ int vb2_verify_kernel_preamble(struct vb2_kernel_preamble *preamble,
 			       const struct vb2_public_key *key,
 			       const struct vb2_workbuf *wb);
 
+/**
+ * Retrieve the 16-bit vmlinuz header address and size from the preamble.
+ *
+ * Size 0 means there is no 16-bit vmlinuz header present.  Old preamble
+ * versions (<2.1) return 0 for both fields.
+ *
+ * @param preamble	Preamble to check
+ * @param vmlinuz_header_address	Destination for header address
+ * @param vmlinuz_header_size		Destination for header size
+ */
+void vb2_kernel_get_vmlinuz_header(const struct vb2_kernel_preamble *preamble,
+				   uint64_t *vmlinuz_header_address,
+				   uint32_t *vmlinuz_header_size);
+
+/**
+ * Get the flags for the kernel preamble.
+ *
+ * @param preamble	Preamble to check
+ * @return Flags for the preamble.  Old preamble versions (<2.2) return 0.
+ */
+uint32_t vb2_kernel_get_flags(const struct vb2_kernel_preamble *preamble);
+
 #endif  /* VBOOT_REFERENCE_VB2_COMMON_H_ */
diff --git a/firmware/lib20/include/vb2_struct.h b/firmware/lib20/include/vb2_struct.h
index f644a5fa..eeaf0cec 100644
--- a/firmware/lib20/include/vb2_struct.h
+++ b/firmware/lib20/include/vb2_struct.h
@@ -268,6 +268,8 @@ struct vb2_kernel_preamble {
 	uint32_t flags;
 } __attribute__((packed));
 
-#define EXPECTED_VB2_KERNEL_PREAMBLE_SIZE 116
+#define EXPECTED_VB2_KERNEL_PREAMBLE_2_0_SIZE 96
+#define EXPECTED_VB2_KERNEL_PREAMBLE_2_1_SIZE 112
+#define EXPECTED_VB2_KERNEL_PREAMBLE_2_2_SIZE 116
 
 #endif  /* VBOOT_REFERENCE_VB2_STRUCT_H_ */
diff --git a/firmware/lib20/kernel.c b/firmware/lib20/kernel.c
index 609f2461..4ded5d55 100644
--- a/firmware/lib20/kernel.c
+++ b/firmware/lib20/kernel.c
@@ -249,11 +249,12 @@ int vb2_verify_kernel_preamble(struct vb2_kernel_preamble *preamble,
 			       const struct vb2_workbuf *wb)
 {
 	struct vb2_signature *sig = &preamble->preamble_signature;
+	uint32_t min_size = EXPECTED_VB2_KERNEL_PREAMBLE_2_0_SIZE;
 
 	VB2_DEBUG("Verifying kernel preamble.\n");
 
-	/* Sanity checks before attempting signature of data */
-	if(size < sizeof(*preamble)) {
+	/* Make sure it's even safe to look at the struct */
+	if(size < min_size) {
 		VB2_DEBUG("Not enough data for preamble header.\n");
 		return VB2_ERROR_PREAMBLE_TOO_SMALL_FOR_HEADER;
 	}
@@ -262,9 +263,14 @@ int vb2_verify_kernel_preamble(struct vb2_kernel_preamble *preamble,
 		VB2_DEBUG("Incompatible kernel preamble header version.\n");
 		return VB2_ERROR_PREAMBLE_HEADER_VERSION;
 	}
-	if (preamble->header_version_minor < 2) {
-		VB2_DEBUG("Old preamble header format not supported\n");
-		return VB2_ERROR_PREAMBLE_HEADER_OLD;
+
+	if (preamble->header_version_minor >= 2)
+		min_size = EXPECTED_VB2_KERNEL_PREAMBLE_2_2_SIZE;
+	else if (preamble->header_version_minor == 1)
+		min_size = EXPECTED_VB2_KERNEL_PREAMBLE_2_1_SIZE;
+	if(preamble->preamble_size < min_size) {
+		VB2_DEBUG("Preamble size too small for header.\n");
+		return VB2_ERROR_PREAMBLE_TOO_SMALL_FOR_HEADER;
 	}
 	if (size < preamble->preamble_size) {
 		VB2_DEBUG("Not enough data for preamble.\n");
@@ -325,7 +331,8 @@ int vb2_verify_kernel_preamble(struct vb2_kernel_preamble *preamble,
 	 * If vmlinuz header is present, verify it's covered by the body
 	 * signature.
 	 */
-	if (preamble->vmlinuz_header_size) {
+	if (preamble->header_version_minor >= 1 &&
+	    preamble->vmlinuz_header_size) {
 		const void *body_ptr =
 			(const void *)(uintptr_t)preamble->body_load_address;
 		const void *vmlinuz_header_ptr = (const void *)
@@ -442,3 +449,30 @@ int vb2_load_kernel_preamble(struct vb2_context *ctx)
 
 	return VB2_SUCCESS;
 }
+
+void vb2_kernel_get_vmlinuz_header(const struct vb2_kernel_preamble *preamble,
+				   uint64_t *vmlinuz_header_address,
+				   uint32_t *vmlinuz_header_size)
+{
+	if (preamble->header_version_minor < 1) {
+		*vmlinuz_header_address = 0;
+		*vmlinuz_header_size = 0;
+	} else {
+		/*
+		 * Set header and size only if the preamble header version is >
+		 * 2.1 as they don't exist in version 2.0 (Note that we don't
+		 * need to check header_version_major; if that's not 2 then
+		 * VerifyKernelPreamble() would have already failed.
+		 */
+		*vmlinuz_header_address = preamble->vmlinuz_header_address;
+		*vmlinuz_header_size = preamble->vmlinuz_header_size;
+	}
+}
+
+uint32_t vb2_kernel_get_flags(const struct vb2_kernel_preamble *preamble)
+{
+	if (preamble->header_version_minor < 2)
+		return 0;
+
+	return preamble->flags;
+}