mb/google/poppy/variants/nami: Add support for getting OEM name from CBFS

This change:
1. Allows mainboard to add OEM table to CBFS
2. Provides mainboard specific smbios_mainboard_manufacturer that reads
OEM ID from EC using CBI and compares it against the OEM ID in CBFS
table to identify the right OEM string.

BUG=b:74617340

Change-Id: Iff54b12745de3efa7be0801c9a3a9f2a57767dde
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/26142
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/mainboard/google/poppy/Kconfig

@@ -111,6 +111,10 @@ config MAX_CPUS
 	int
 	default 8
 
+config OEM_BIN_FILE
+	string "OEM ID table"
+	default ""
+
 config TPM_TIS_ACPI_INTERRUPT
 	int
 	default 64  # GPE0_DW2_00 (GPP_E0)

src/mainboard/google/poppy/variants/nami/Makefile.inc

@@ -33,3 +33,8 @@ ramstage-y += gpio.c
 ramstage-y += nhlt.c
 ramstage-y += pl2.c
 ramstage-y += mainboard.c
+
+# Add OEM ID table
+cbfs-files-y += oem.bin
+oem.bin-file := $(call strip_quotes,$(CONFIG_OEM_BIN_FILE))
+oem.bin-type := raw

src/mainboard/google/poppy/variants/nami/mainboard.c

@@ -16,7 +16,10 @@
 #include <arch/cpu.h>
 #include <assert.h>
 #include <baseboard/variants.h>
+#include <cbfs.h>
 #include <chip.h>
+#include <commonlib/cbfs_serialized.h>
+#include <compiler.h>
 #include <device/device.h>
 #include <ec/google/chromeec/ec.h>
 #include <smbios.h>
@@ -62,3 +65,77 @@ const char *smbios_mainboard_sku(void)
 
 	return sku_str;
 }
+
+#define OEM_UNKNOWN	0xff
+
+/*
+ * Read OEM ID from EC using cbi commands.
+ * Return value:
+ * Success = OEM ID read from EC
+ * Failure = OEM_UNKNOWN (0xff)
+ */
+static uint8_t read_oem_id(void)
+{
+	static uint8_t oem_id = OEM_UNKNOWN;
+	uint32_t id;
+
+	if (oem_id != OEM_UNKNOWN)
+		return oem_id;
+
+	if (google_chromeec_cbi_get_oem_id(&id))
+		return OEM_UNKNOWN;
+
+	if (id > OEM_UNKNOWN) {
+		printk(BIOS_ERR, "%s: OEM ID too big %u!\n", __func__, id);
+		return OEM_UNKNOWN;
+	}
+
+	oem_id = id;
+	printk(BIOS_DEBUG, "%s: OEM ID=%d\n", __func__, oem_id);
+
+	return oem_id;
+}
+
+/* "oem.bin" in cbfs contains array of records using the following structure. */
+struct oem_mapping {
+	uint8_t oem_id;
+	char oem_name[10];
+} __packed;
+
+/* Local buffer to read "oem.bin" */
+static char oem_bin_data[200];
+
+const char *smbios_mainboard_manufacturer(void)
+{
+	uint8_t oem_id = read_oem_id();
+	const struct oem_mapping *oem_entry = (void *)&oem_bin_data;
+	size_t oem_data_size;
+	size_t curr = 0;
+	static const char *manuf;
+
+	if (manuf)
+		return manuf;
+
+	/* If OEM ID cannot be determined, return default manuf string. */
+	if (oem_id == OEM_UNKNOWN)
+		return CONFIG_MAINBOARD_SMBIOS_MANUFACTURER;
+
+	oem_data_size = cbfs_boot_load_file("oem.bin", oem_bin_data,
+					    sizeof(oem_bin_data),
+					    CBFS_TYPE_RAW);
+
+	while ((curr < oem_data_size) &&
+	       ((oem_data_size - curr) >= sizeof(*oem_entry))) {
+		if (oem_id == oem_entry->oem_id) {
+			manuf = oem_entry->oem_name;
+			break;
+		}
+		curr += sizeof(*oem_entry);
+		oem_entry++;
+	}
+
+	if (manuf == NULL)
+		manuf = CONFIG_MAINBOARD_SMBIOS_MANUFACTURER;
+
+	return manuf;
+}