CHROMIUM: use a fixed binary layout of crossystem data

The twostop design is envolved that crossysmem data is now not
reinitialized again in readwrite main firmware, and relied on bootstub
passing the blob around.

Thus, the blob should have a fixed binary layout so that future
readwrite main firmware can reliably parse the blob contents. Currently
the readwrite main firmware just check the sanity of the blob.

BUG=chromium-os:17876
TEST=crossystem blob passes the sanity check by readwrite main firmware

Change-Id: I2981c10234c20d34e1405b5ab127bdc90faa2e3d
Reviewed-on: http://gerrit.chromium.org/gerrit/4373
Tested-by: Che-Liang Chiou <clchiou@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

1 files changed, 52 insertions, 25 deletions

diff --git a/include/chromeos/crossystem_data.h b/include/chromeos/crossystem_data.h
index ce7ffddcaf..8a7237e319 100644
--- a/include/chromeos/crossystem_data.h
+++ b/include/chromeos/crossystem_data.h
@@ -28,29 +28,47 @@
 
 /* the data blob format */
 typedef struct {
-	uint32_t	total_size;
-	char		signature[10];
-	uint16_t	version;
-	uint64_t	nvcxt_lba;
-	uint16_t	vbnv[2];
-	uint8_t		nvcxt_cache[VBNV_BLOCK_SIZE];
-	uint8_t		write_protect_sw;
-	uint8_t		recovery_sw;
-	uint8_t		developer_sw;
-	int		gpio_port_write_protect_sw;
-	int		gpio_port_recovery_sw;
-	int		gpio_port_developer_sw;
-	uint8_t		polarity_write_protect_sw;
-	uint8_t		polarity_recovery_sw;
-	uint8_t		polarity_developer_sw;
-	uint8_t		binf[5];
-	uint32_t	chsw;
-	char 		hwid[ID_LEN];
-	char		fwid[ID_LEN];
-	char		frid[ID_LEN];
-	uint32_t	fmap_base;
-	uint8_t		vbshared_data[VB_SHARED_DATA_REC_SIZE];
-} crossystem_data_t;
+	uint32_t	total_size;				/* 0000 */
+	uint8_t		signature[10];				/* 0004 */
+	uint16_t	version;				/* 000c */
+
+	uint64_t	nvcxt_lba;				/* 0010 */
+	uint16_t	vbnv[2];				/* 0018 */
+	uint8_t		nvcxt_cache[VBNV_BLOCK_SIZE];		/* 001c */
+
+	uint8_t		write_protect_sw;			/* 002c */
+	uint8_t		recovery_sw;				/* 002d */
+	uint8_t		developer_sw;				/* 002e */
+	uint8_t		pad1[1];
+
+	uint32_t	gpio_port_write_protect_sw;		/* 0030 */
+	uint32_t	gpio_port_recovery_sw;			/* 0034 */
+	uint32_t	gpio_port_developer_sw;			/* 0038 */
+
+	uint8_t		polarity_write_protect_sw;		/* 003c */
+	uint8_t		polarity_recovery_sw;			/* 003d */
+	uint8_t		polarity_developer_sw;			/* 003e */
+	uint8_t		pad2[1];
+
+	uint8_t		binf[5];				/* 0040 */
+	uint8_t		pad3[1];
+	uint32_t	chsw;					/* 0046 */
+
+	uint8_t 	hwid[ID_LEN];				/* 004a */
+	uint8_t		fwid[ID_LEN];				/* 014a */
+	uint8_t		frid[ID_LEN];				/* 024a */
+
+	uint32_t	fmap_base;				/* 034a */
+	uint8_t		pad4[2];
+
+	/*
+	 * VbSharedData contains fields of long word (64-bit) type, and so it
+	 * should better be aligned on a 8-byte boundary on ARM platforms.
+	 * Although ARM processors can access unaligned addresses, this feature
+	 * is generally not enabled in U-Boot.
+	 */
+	uint8_t		vbshared_data[VB_SHARED_DATA_REC_SIZE];	/* 0350 */
+} __attribute__((packed)) crossystem_data_t;
 
 /**
  * This initializes the data blob that we will pass to kernel, and later be
@@ -69,11 +87,20 @@ typedef struct {
  * @param devsw stores the value of developer mode gpio
  * @return 0 if it succeeds; non-zero if it fails
  */
-int crossystem_data_init(crossystem_data_t *cdata, char *frid,
+int crossystem_data_init(crossystem_data_t *cdata, uint8_t *frid,
 		uint32_t fmap_data, void *gbb_data, void *nvcxt_raw,
 		cros_gpio_t *wpsw, cros_gpio_t *recsw, cros_gpio_t *devsw);
 
 /**
+ * This checks sanity of the crossystem data blob. Readwrite main firmware
+ * should check the sanity of crossystem data that bootstub passes to it.
+ *
+ * @param cdata is the data blob shared with crossystem
+ * @return 0 if it succeeds; non-zero if the sanity check fails
+ */
+int crossystem_data_check_integrity(crossystem_data_t *cdata);
+
+/**
  * This sets rewritable firmware id. It should only be called in non-recovery
  * boots.
  *
@@ -81,7 +108,7 @@ int crossystem_data_init(crossystem_data_t *cdata, char *frid,
  * @param fwid r/w firmware id; a zero-terminated string shorter than ID_LEN
  * @return 0 if it succeeds; non-zero if it fails
  */
-int crossystem_data_set_fwid(crossystem_data_t *cdata, char *fwid);
+int crossystem_data_set_fwid(crossystem_data_t *cdata, uint8_t *fwid);
 
 /**
  * This sets active main firmware and its type.