efi_loader: add SMBIOS table measurement

TCG PC Client Platform Firmware Profile Specification
requires to measure the SMBIOS table that contains static
configuration information (e.g. Platform Manufacturer
Enterprise Number assigned by IANA, platform model number,
Vendor and Device IDs for each SMBIOS table).

The device- and environment-dependent information such as
serial number is cleared to zero or space character for
the measurement.

Existing smbios_string() function returns pointer to the string
with const qualifier, but exisintg use case is updating version
string and const qualifier must be removed.
This commit removes const qualifier from smbios_string()
return value and reuses to clear the strings for the measurement.

This commit also fixes the following compiler warning:

lib/smbios-parser.c:59:39: warning: cast to pointer from integer of
different size [-Wint-to-pointer-cast]
  const struct smbios_header *header = (struct smbios_header *)entry->struct_table_address;

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/include/smbios.h b/include/smbios.h
index aa6b6f3849..acfcbfe2ca 100644
--- a/include/smbios.h
+++ b/include/smbios.h
@@ -260,9 +260,9 @@ const struct smbios_header *smbios_header(const struct smbios_entry *entry, int
  *
  * @header:    pointer to struct smbios_header
  * @index:     string index
- * @return:    NULL or a valid const char pointer
+ * @return:    NULL or a valid char pointer
  */
-const char *smbios_string(const struct smbios_header *header, int index);
+char *smbios_string(const struct smbios_header *header, int index);
 
 /**
  * smbios_update_version() - Update the version string
@@ -292,4 +292,17 @@ int smbios_update_version(const char *version);
  */
 int smbios_update_version_full(void *smbios_tab, const char *version);
 
+/**
+ * smbios_prepare_measurement() - Update smbios table for the measurement
+ *
+ * TCG specification requires to measure static configuration information.
+ * This function clear the device dependent parameters such as
+ * serial number for the measurement.
+ *
+ * @entry: pointer to a struct smbios_entry
+ * @header: pointer to a struct smbios_header
+ */
+void smbios_prepare_measurement(const struct smbios_entry *entry,
+				struct smbios_header *header);
+
 #endif /* _SMBIOS_H_ */