drivers/vpd: add framework to search VPD in romstage

Summary:
Added a framework to search VPD in romstage before memory is
avilable. vpd_cbmem.c and vpd_premem.c are added for
code specific for premem environment and for environment that
cbmem can be used.

Since global variable is forbidden in romstage. A CAR_GLOBAL
variable is defined in vpd.c. This variable holds VPD binary
blobs' base address and size from memory mapped flash.

The overall flow is:
* The CAR variable g_vpd_blob is initialized if it was not,
either at romstage (before FSP-M execution in case of FSP UPD
customization), or at ramstage.
* At ramstage, during CBMEM_INIT, the VPD binary blob contents
are copied into CBMEM.
* At vpd_find() which may be called at romstage or at ramstage,
it sets storage for a local struct vpd_blob variable.
  * The variable gets contents duplicated from g_vpd_blob, if
vpd_find() is called at romstage.
  * The variable gets contents obtained from CBMEM, if vpd_find()
is called at ramstage.

Added a call vpd_get_bool(). Given a key/value pair in VPD
binary blob, and name of a bool type variable, set the variable
value if there is a match.
Several checks are in place:
* The key/value length needs to be correct.
* The key name needs to match.
* THe value is either '1' or '0'.

Test Plan:
* Build an OCP MonoLake coreboot image, flash and run.

Tags:
Signed-off-by: Jonathan Zhang <jonzhang@fb.com>
Change-Id: Iebdba59419a555147fc40391cf17cc6879d9e1b2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34634
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/src/drivers/vpd/vpd.h b/src/drivers/vpd/vpd.h
index 6009b8bc0d..14b002c8f6 100644
--- a/src/drivers/vpd/vpd.h
+++ b/src/drivers/vpd/vpd.h
@@ -7,11 +7,37 @@
 #ifndef __VPD_H__
 #define __VPD_H__
 
+#define GOOGLE_VPD_2_0_OFFSET 0x600
+
 enum vpd_region {
 	VPD_ANY = 0,
 	VPD_RO = 1,
 	VPD_RW = 2
 };
+
+/* VPD 2.0 data blob structure */
+struct vpd_blob {
+	bool initialized;
+	uint8_t  *ro_base;
+	uint32_t ro_size;
+	uint8_t  *rw_base;
+	uint32_t rw_size;
+};
+extern struct vpd_blob g_vpd_blob;
+
+/*
+ * This function loads g_vpd_blob CAR_GLOBAL variable.
+ * The variable is initialized if it was not.
+ */
+const struct vpd_blob *vpd_load_blob(void);
+
+/*
+ * This function gets the base address and size of
+ * buffers for RO_VPD/RW_VPD binary blobs, and sets
+ * the struct.
+ */
+void vpd_get_buffers(struct vpd_blob *blob);
+
 /*
  * Reads VPD string value by key.
  *
@@ -39,4 +65,13 @@ char *vpd_gets(const char *key, char *buffer, int size, enum vpd_region region);
 
 const void *vpd_find(const char *key, int *size, enum vpd_region region);
 
+/*
+ * Find value of boolean type vpd key.
+ *
+ * During the process, necessary checking is done, such as making
+ * sure the value length is 1, and value is either '1' or '0'.
+ */
+bool vpd_get_bool(const char *key, enum vpd_region region,
+	uint8_t *val);
+
 #endif  /* __VPD_H__ */