dmidecode: Add a --no-quirks option

This new option is aimed at firmware developers to help them validate
their work. When this option is used, quirks and fixups are disabled
in dmidecode, which will dumbly decode everything found in the table
even if it is known to be incorrect.

Signed-off-by: Jean Delvare <[email protected]>

Author: jdelvare

dmidecode.c

@@ -2722,7 +2722,7 @@ static void dmi_memory_device_width(const char *attr, u16 code)
 	/*
 	 * If no memory module is present, width may be 0
 	 */
-	if (code == 0xFFFF || code == 0)
+	if (code == 0xFFFF || (code == 0 && !(opt.flags & FLAG_NO_QUIRKS)))
 		pr_attr(attr, "Unknown");
 	else
 		pr_attr(attr, "%u bits", code);
@@ -4720,7 +4720,7 @@ static void dmi_decode(const struct dmi_header *h, u16 ver)
 			dmi_memory_device_type_detail(WORD(data + 0x13));
 			if (h->length < 0x17) break;
 			/* If no module is present, the remaining fields are irrelevant */
-			if (WORD(data + 0x0C) == 0)
+			if (WORD(data + 0x0C) == 0 && !(opt.flags & FLAG_NO_QUIRKS))
 				break;
 			dmi_memory_device_speed("Speed", WORD(data + 0x15),
 						h->length >= 0x5C ?
@@ -5544,7 +5544,7 @@ static void dmi_table_decode(u8 *buf, u32 len, u16 num, u16 ver, u32 flags)
 		}
 
 		/* Fixup a common mistake */
-		if (h.type == 34)
+		if (h.type == 34 && !(opt.flags & FLAG_NO_QUIRKS))
 			dmi_fixup_type_34(&h, display);
 
 		if (display)
@@ -5735,6 +5735,29 @@ static int smbios3_decode(u8 *buf, const char *devmem, u32 flags)
 	return 1;
 }
 
+static void dmi_fixup_version(u16 *ver)
+{
+	/* Some BIOS report weird SMBIOS version, fix that up */
+	switch (*ver)
+	{
+		case 0x021F:
+		case 0x0221:
+			if (!(opt.flags & FLAG_QUIET))
+				fprintf(stderr,
+					"SMBIOS version fixup (2.%d -> 2.%d).\n",
+					*ver & 0xFF, 3);
+			*ver = 0x0203;
+			break;
+		case 0x0233:
+			if (!(opt.flags & FLAG_QUIET))
+				fprintf(stderr,
+					"SMBIOS version fixup (2.%d -> 2.%d).\n",
+					51, 6);
+			*ver = 0x0206;
+			break;
+	}
+}
+
 static int smbios_decode(u8 *buf, const char *devmem, u32 flags)
 {
 	u16 ver;
@@ -5759,25 +5782,8 @@ static int smbios_decode(u8 *buf, const char *devmem, u32 flags)
 		return 0;
 
 	ver = (buf[0x06] << 8) + buf[0x07];
-	/* Some BIOS report weird SMBIOS version, fix that up */
-	switch (ver)
-	{
-		case 0x021F:
-		case 0x0221:
-			if (!(opt.flags & FLAG_QUIET))
-				fprintf(stderr,
-					"SMBIOS version fixup (2.%d -> 2.%d).\n",
-					ver & 0xFF, 3);
-			ver = 0x0203;
-			break;
-		case 0x0233:
-			if (!(opt.flags & FLAG_QUIET))
-				fprintf(stderr,
-					"SMBIOS version fixup (2.%d -> 2.%d).\n",
-					51, 6);
-			ver = 0x0206;
-			break;
-	}
+	if (!(opt.flags & FLAG_NO_QUIRKS))
+		dmi_fixup_version(&ver);
 	if (!(opt.flags & FLAG_QUIET))
 		pr_info("SMBIOS %u.%u present.",
 			ver >> 8, ver & 0xFF);

dmiopt.c

@@ -270,6 +270,7 @@ int parse_command_line(int argc, char * const argv[])
 		{ "dev-mem", required_argument, NULL, 'd' },
 		{ "help", no_argument, NULL, 'h' },
 		{ "quiet", no_argument, NULL, 'q' },
+		{ "no-quirks", no_argument, NULL, 'Q' },
 		{ "string", required_argument, NULL, 's' },
 		{ "type", required_argument, NULL, 't' },
 		{ "dump", no_argument, NULL, 'u' },
@@ -302,6 +303,9 @@ int parse_command_line(int argc, char * const argv[])
 			case 'q':
 				opt.flags |= FLAG_QUIET;
 				break;
+			case 'Q':
+				opt.flags |= FLAG_NO_QUIRKS;
+				break;
 			case 's':
 				if (parse_opt_string(optarg) < 0)
 					return -1;
@@ -371,6 +375,7 @@ void print_help(void)
 		" -d, --dev-mem FILE     Read memory from device FILE (default: " DEFAULT_MEM_DEV ")\n"
 		" -h, --help             Display this help text and exit\n"
 		" -q, --quiet            Less verbose output\n"
+		"     --no-quirks        Decode everything without quirks\n"
 		" -s, --string KEYWORD   Only display the value of the given DMI string\n"
 		" -t, --type TYPE        Only display the entries of given type\n"
 		" -H, --handle HANDLE    Only display the entry of given handle\n"

dmiopt.h

@@ -46,6 +46,7 @@ extern struct opt opt;
 #define FLAG_DUMP_BIN           (1 << 4)
 #define FLAG_FROM_DUMP          (1 << 5)
 #define FLAG_NO_SYSFS           (1 << 6)
+#define FLAG_NO_QUIRKS          (1 << 7)
 
 int parse_command_line(int argc, char * const argv[]);
 void print_help(void);

man/dmidecode.8

@@ -70,6 +70,11 @@ Read memory from device \fIFILE\fP (default: \fI/dev/mem\fP)
 Be less verbose. Unknown, inactive and \s-1OEM\s0-specific entries are not
 displayed. Meta-data and handle references are hidden.
 .TP
+.BR "  " "  " "--no-quirks"
+Decode everything exactly as it is in the table, without trying to fix up
+common mistakes or hide irrelevant fields.
+This mode is primarily aimed at firmware developers.
+.TP
 .BR "-s" ", " "--string \fIKEYWORD\fP"
 Only display the value of the \s-1DMI\s0 string identified by \fIKEYWORD\fP.
 It must be a keyword from the following list: