src/arch/x86/smbios.c: Fix type 17 part number

Some DIMMs have invalid strings when it comes to device part number
(bytes 0x149-0x15c). From DDR4 SPD specs it should be ASCIIZ with unused
space filled with white spaces (ASCII 0x20). Byte 20 should be 0 (ASCIIZ),
all others should be ASCII.

Create a test that detects invalid strings and replace invalid
characters with *. If a replacement was made the output string then must
be <Invalid (replaced string)>.

BUG=b:73122207
TEST=Build, boot and record serial output for kahlee while injecting
different strings to dmi17->PartNumber. Use code to examine SMBIOS,
while testing different valid and invalid strings.
Remove string injection before committing.

Change-Id: Iead2a4cb14ff28d263d7214111b637e62ebd2921
Signed-off-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Reviewed-on: https://review.coreboot.org/23844
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

2 files changed, 36 insertions, 13 deletions

diff --git a/src/arch/x86/smbios.c b/src/arch/x86/smbios.c
index 548e6ed741..e1743086e7 100644
--- a/src/arch/x86/smbios.c
+++ b/src/arch/x86/smbios.c
@@ -195,11 +195,34 @@ void smbios_fill_dimm_manufacturer_from_id(uint16_t mod_id,
 	}
 }
 
+/* This function will fill the corresponding part number */
+static void smbios_fill_dimm_part_number(char *part_number,
+	struct smbios_type17 *t)
+{
+	int i, invalid;
+
+	invalid = 0; /* assume valid */
+	for (i = 0; i < DIMM_INFO_PART_NUMBER_SIZE - 1; i++) {
+		if (part_number[i] < ' ') {
+			invalid = 1;
+			part_number[i] = '*';
+		}
+	}
+	if (invalid) {
+		char string_buffer[64];
+
+		snprintf(string_buffer, sizeof(string_buffer), "Invalid (%s)",
+								part_number);
+		t->part_number = smbios_add_string(t->eos, string_buffer);
+	} else
+		t->part_number = smbios_add_string(t->eos, part_number);
+
+}
+
 static int create_smbios_type17_for_dimm(struct dimm_info *dimm,
 					 unsigned long *current, int *handle)
 {
 	struct smbios_type17 *t = (struct smbios_type17 *)*current;
-	uint8_t length;
 	char locator[40];
 
 	memset(t, 0, sizeof(struct smbios_type17));
@@ -236,8 +259,7 @@ static int create_smbios_type17_for_dimm(struct dimm_info *dimm,
 
 	smbios_fill_dimm_manufacturer_from_id(dimm->mod_id, t);
 	/* put '\0' in the end of data */
-	length = sizeof(dimm->serial);
-	dimm->serial[length - 1] = '\0';
+	dimm->serial[DIMM_INFO_SERIAL_SIZE - 1] = '\0';
 	if (dimm->serial[0] == 0)
 		t->serial_number = smbios_add_string(t->eos, "None");
 	else
@@ -252,10 +274,8 @@ static int create_smbios_type17_for_dimm(struct dimm_info *dimm,
 	t->bank_locator = smbios_add_string(t->eos, locator);
 
 	/* put '\0' in the end of data */
-	length = sizeof(dimm->module_part_number);
-	dimm->module_part_number[length - 1] = '\0';
-	t->part_number = smbios_add_string(t->eos,
-				      (const char *)dimm->module_part_number);
+	dimm->module_part_number[DIMM_INFO_PART_NUMBER_SIZE - 1] = '\0';
+	smbios_fill_dimm_part_number((char *)dimm->module_part_number, t);
 
 	/* Synchronous = 1 */
 	t->type_detail = 0x0080;
diff --git a/src/include/memory_info.h b/src/include/memory_info.h
index 8569ee493a..a1b3553a77 100644
--- a/src/include/memory_info.h
+++ b/src/include/memory_info.h
@@ -19,6 +19,10 @@
 #include <stdint.h>
 #include <compiler.h>
 
+#define DIMM_INFO_SERIAL_SIZE		5
+#define DIMM_INFO_PART_NUMBER_SIZE	19
+#define DIMM_INFO_TOTAL			8	/* Maximum num of dimm is 8 */
+
 /*
  * If this table is filled and put in CBMEM,
  * then these info in CBMEM will be used to generate smbios type 17 table
@@ -31,10 +35,10 @@ struct dimm_info {
 	uint8_t channel_num;
 	uint8_t dimm_num;
 	uint8_t bank_locator;
-	/* The 5th byte is '\0' for the end of string */
-	uint8_t serial[5];
-	/* The 19th byte is '\0' for the end of string */
-	uint8_t module_part_number[19];
+	/* The last byte is '\0' for the end of string */
+	uint8_t serial[DIMM_INFO_SERIAL_SIZE];
+	/* The last byte is '\0' for the end of string */
+	uint8_t module_part_number[DIMM_INFO_PART_NUMBER_SIZE];
 	uint16_t mod_id;
 	uint8_t mod_type;
 	uint8_t bus_width;
@@ -42,8 +46,7 @@ struct dimm_info {
 
 struct memory_info {
 	uint8_t dimm_cnt;
-	/* Maximum num of dimm is 8 */
-	struct dimm_info dimm[8];
+	struct dimm_info dimm[DIMM_INFO_TOTAL];
 } __packed;
 
 #endif