CBI: Share common code between host tool and firmware

This patch makes EC firmware and cbi-util share the common code.

BUG=b:70294260
BRANCH=none
TEST=Set fields using ectool. Verify the contents by cbi command.
Verify cbi-util creates the same binary as before.
Verify emerge ec-utils ec-devutils pass.

Change-Id: If5e65e48dd03960e0adf23ef775f67aecf785d85
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/932001

4 files changed, 89 insertions, 60 deletions

diff --git a/common/cbi.c b/common/cbi.c
index 935861c2a6..be22642497 100644
--- a/common/cbi.c
+++ b/common/cbi.c
@@ -13,7 +13,52 @@
 #include "host_command.h"
 #include "i2c.h"
 #include "timer.h"
+
+#ifdef HOST_TOOLS_BUILD
+#include <string.h>
+#else
 #include "util.h"
+#endif
+
+/*
+ * Functions and variables defined here shared with host tools (e.g. cbi-util).
+ * TODO: Move these to common/cbi/cbi.c and common/cbi/utils.c if they grow.
+ */
+uint8_t cbi_crc8(const struct cbi_header *h)
+{
+	return crc8((uint8_t *)&h->crc + 1,
+		    h->total_size - sizeof(h->magic) - sizeof(h->crc));
+}
+
+uint8_t *cbi_set_data(uint8_t *p, enum cbi_data_tag tag,
+		      const void *buf, int size)
+{
+	struct cbi_data *d = (struct cbi_data *)p;
+	d->tag = tag;
+	d->size = size;
+	memcpy(d->value, buf, size);
+	p += sizeof(*d) + size;
+	return p;
+}
+
+struct cbi_data *cbi_find_tag(const void *cbi, enum cbi_data_tag tag)
+{
+	struct cbi_data *d;
+	const struct cbi_header *h = cbi;
+	const uint8_t *p;
+	for (p = h->data; p + sizeof(*d) < (uint8_t *)cbi + h->total_size;) {
+		d = (struct cbi_data *)p;
+		if (d->tag == tag)
+			return d;
+		p += sizeof(*d) + d->size;
+	}
+	return NULL;
+}
+
+/*
+ * Functions and variables specific to EC firmware
+ */
+#ifndef HOST_TOOLS_BUILD
 
 #define CPRINTS(format, args...) cprints(CC_SYSTEM, "CBI " format, ## args)
 
@@ -25,12 +70,6 @@ static int cached_read_result = EC_ERROR_CBI_CACHE_INVALID;
 static uint8_t cbi[CBI_EEPROM_SIZE];
 static struct cbi_header * const head = (struct cbi_header *)cbi;
 
-static uint8_t cbi_crc8(const struct cbi_header *h)
-{
-	return crc8((uint8_t *)&h->crc + 1,
-		    h->total_size - sizeof(h->magic) - sizeof(h->crc));
-}
-
 static int read_eeprom(uint8_t offset, uint8_t *in, int in_size)
 {
 	return i2c_xfer(I2C_PORT_EEPROM, I2C_ADDR_EEPROM,
@@ -99,19 +138,6 @@ static int read_board_info(void)
 	return cached_read_result;
 }
 
-static struct cbi_data *find_tag(enum cbi_data_tag tag)
-{
-	struct cbi_data *d;
-	uint8_t *p;
-	for (p = head->data; p + sizeof(*d) < cbi + head->total_size;) {
-		d = (struct cbi_data *)p;
-		if (d->tag == tag)
-			return d;
-		p += sizeof(*d) + d->size;
-	}
-	return NULL;
-}
-
 int cbi_get_board_info(enum cbi_data_tag tag, uint8_t *buf, uint8_t *size)
 {
 	const struct cbi_data *d;
@@ -119,7 +145,7 @@ int cbi_get_board_info(enum cbi_data_tag tag, uint8_t *buf, uint8_t *size)
 	if (read_board_info())
 		return EC_ERROR_UNKNOWN;
 
-	d = find_tag(tag);
+	d = cbi_find_tag(cbi, tag);
 	if (!d)
 		/* Not found */
 		return EC_ERROR_UNKNOWN;
@@ -139,16 +165,13 @@ int cbi_set_board_info(enum cbi_data_tag tag, const uint8_t *buf, uint8_t size)
 {
 	struct cbi_data *d;
 
-	d = find_tag(tag);
+	d = cbi_find_tag(cbi, tag);
 	if (!d) {
 		/* Not found. Check if new item would fit */
 		if (sizeof(cbi) < head->total_size + sizeof(*d) + size)
 			return EC_ERROR_OVERFLOW;
 		/* Append new item */
-		d = (struct cbi_data *)&cbi[head->total_size];
-		d->tag = tag;
-		d->size = size;
-		memcpy(d->value, buf, d->size);
+		cbi_set_data(&cbi[head->total_size], tag, buf, size);
 		head->total_size += (sizeof(*d) + size);
 		return EC_SUCCESS;
 	}
@@ -331,3 +354,4 @@ static int cc_cbi(int argc, char **argv)
 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(cbi, cc_cbi, NULL, NULL);
+#endif /* !HOST_TOOLS_BUILD */
diff --git a/include/cros_board_info.h b/include/cros_board_info.h
index eb239f9696..fb667ef899 100644
--- a/include/cros_board_info.h
+++ b/include/cros_board_info.h
@@ -62,4 +62,39 @@ int cbi_get_oem_id(uint32_t *oem_id);
 int cbi_get_board_info(enum cbi_data_tag tag, uint8_t *buf, uint8_t *size);
 int cbi_set_board_info(enum cbi_data_tag tag, const uint8_t *buf, uint8_t size);
 
+/*
+ * Utility functions
+ */
+
+/**
+ * Calculate 8-bit CRC of CBI
+ *
+ * @param h	Pointer to CBI header
+ * @return	CRC value
+ */
+uint8_t cbi_crc8(const struct cbi_header *h);
+
+/**
+ * Store data in memory in CBI data format
+ *
+ * @param p	Pointer to the buffer where a new data item will be stored. It
+ * 		should be pointing to the data section of CBI.
+ * @param tag	Tag of the data item
+ * @param buf	Pointer to the buffer containing the data being copied.
+ * @param size	Size of the data
+ * @return	Address of the byte following the stored data in the
+ * 		destination buffer
+ */
+uint8_t *cbi_set_data(uint8_t *p, enum cbi_data_tag tag,
+		      const void *buf, int size);
+
+/**
+ * Find a data field in CBI
+ *
+ * @param cbi	Buffer containing CBI struct
+ * @param tag	Tag of the data field to search
+ * @return	Pointer to the data or NULL if not found.
+ */
+struct cbi_data *cbi_find_tag(const void *cbi, enum cbi_data_tag tag);
+
 #endif /* __CROS_EC_CROS_BOARD_INFO_H */
diff --git a/util/build.mk b/util/build.mk
index 7a1ab8b766..1879a0a2a5 100644
--- a/util/build.mk
+++ b/util/build.mk
@@ -57,7 +57,7 @@ $(out)/util/gen_touchpad_hash: BUILD_CFLAGS += $(OPENSSL_CFLAGS)
 $(out)/util/gen_touchpad_hash: BUILD_LDFLAGS += $(OPENSSL_LDFLAGS)
 endif # CONFIG_TOUCHPAD_VIRTUAL_OFF
 
-cbi-util-objs=../common/crc8.o
+cbi-util-objs=../common/crc8.o ../common/cbi.o
 
 $(out)/util/export_taskinfo.so: $(out)/util/export_taskinfo_ro.o \
 			$(out)/util/export_taskinfo_rw.o
diff --git a/util/cbi-util.c b/util/cbi-util.c
index c104e54eae..5f8cddc128 100644
--- a/util/cbi-util.c
+++ b/util/cbi-util.c
@@ -137,22 +137,6 @@ static uint8_t *read_file(const char *filename, uint32_t *size_ptr)
 	return buf;
 }
 
-static int cbi_crc8(const struct cbi_header *h)
-{
-	return crc8((uint8_t *)&h->crc + 1,
-		    h->total_size - sizeof(h->magic) - sizeof(h->crc));
-}
-
-static uint8_t *set_data(uint8_t *p, enum cbi_data_tag tag, void *buf, int size)
-{
-	struct cbi_data *d = (struct cbi_data *)p;
-	d->tag = tag;
-	d->size = size;
-	memcpy(d->value, buf, size);
-	p += sizeof(*d) + size;
-	return p;
-}
-
 /*
  * Create a CBI blob
  */
@@ -176,10 +160,10 @@ static int do_create(const char *cbi_filename, uint32_t size, uint8_t erase,
 	h->major_version = CBI_VERSION_MAJOR;
 	h->minor_version = CBI_VERSION_MINOR;
 	p = h->data;
-	p = set_data(p, CBI_TAG_BOARD_VERSION,
+	p = cbi_set_data(p, CBI_TAG_BOARD_VERSION,
 		     &bi->version, sizeof(bi->version));
-	p = set_data(p, CBI_TAG_OEM_ID, &bi->oem_id, sizeof(bi->oem_id));
-	p = set_data(p, CBI_TAG_SKU_ID, &bi->sku_id, sizeof(bi->sku_id));
+	p = cbi_set_data(p, CBI_TAG_OEM_ID, &bi->oem_id, sizeof(bi->oem_id));
+	p = cbi_set_data(p, CBI_TAG_SKU_ID, &bi->sku_id, sizeof(bi->sku_id));
 	h->total_size = p - cbi;
 	h->crc = cbi_crc8(h);
 
@@ -195,24 +179,10 @@ static int do_create(const char *cbi_filename, uint32_t size, uint8_t erase,
 	return 0;
 }
 
-static struct cbi_data *find_tag(const uint8_t *cbi, enum cbi_data_tag tag)
-{
-	struct cbi_data *d;
-	const struct cbi_header *h = (const struct cbi_header *)cbi;
-	const uint8_t *p;
-	for (p = h->data; p + sizeof(*d) < cbi + h->total_size;) {
-		d = (struct cbi_data *)p;
-		if (d->tag == tag)
-			return d;
-		p += sizeof(*d) + d->size;
-	}
-	return NULL;
-}
-
 static void print_integer(const uint8_t *buf, enum cbi_data_tag tag)
 {
 	uint32_t v;
-	struct cbi_data *d = find_tag(buf, tag);
+	struct cbi_data *d = cbi_find_tag(buf, tag);
 	const char *name = d->tag < CBI_TAG_COUNT ? field_name[d->tag] : "???";
 
 	if (!d)