lib/vsprintf: allow printing upper case GUIDs

In the UEFI context GUIDs are expected to be rendered in upper case.

The patch uses the formerly unused bit 1 of the parameter str_format
of function uuid_bin_to_str() to indicate if we need upper or lower case
output.

Function uuid_string() in vsprint.c is adjusted to correctly set the bit
depending on the print format code.

%pUb: 01020304-0506-0708-090a-0b0c0d0e0f10
%pUB: 01020304-0506-0708-090A-0B0C0D0E0F10
%pUl: 04030201-0605-0807-090a-0b0c0d0e0f10
%pUL: 04030201-0605-0807-090A-0B0C0D0E0F10

Up to this point only a diagnostic message in mount_ubifs() using '%pUB' is
concerned by the change. Further patches are needed to adjust the UEFI
subsystem.

A unit test is provided inside the ut_print command.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

include/uuid.h

@@ -6,6 +6,8 @@
 #ifndef __UUID_H__
 #define __UUID_H__
 
+#include <linux/bitops.h>
+
 /* This is structure is in big-endian */
 struct uuid {
 	unsigned int time_low;
@@ -16,10 +18,10 @@ struct uuid {
 	unsigned char node[6];
 } __packed;
 
-enum {
+/* Bits of a bitmask specifying the output format for GUIDs */
-	UUID_STR_FORMAT_STD,
+#define UUID_STR_FORMAT_STD	0
-	UUID_STR_FORMAT_GUID
+#define UUID_STR_FORMAT_GUID	BIT(0)
-};
+#define UUID_STR_UPPER_CASE	BIT(1)
 
 #define UUID_STR_LEN		36
 #define UUID_BIN_LEN		sizeof(struct uuid)

lib/uuid.c

@@ -187,9 +187,10 @@ int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
 /*
  * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
  *
- * @param uuid_bin - pointer to binary data of UUID (big endian) [16B]
+ * @param uuid_bin:	pointer to binary data of UUID (big endian) [16B]
- * @param uuid_str - pointer to allocated array for output string [37B]
+ * @param uuid_str:	pointer to allocated array for output string [37B]
- * @str_format     - UUID string format: 0 - UUID; 1 - GUID
+ * @str_format:		bit 0: 0 - UUID; 1 - GUID
+ *			bit 1: 0 - lower case; 2 - upper case
  */
 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
 {
@@ -198,6 +199,7 @@ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
 	const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
 						  9, 10, 11, 12, 13, 14, 15};
 	const u8 *char_order;
+	const char *format;
 	int i;
 
 	/*
@@ -205,13 +207,17 @@ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
 	 * 4B-2B-2B-2B-6B
 	 * be be be be be
 	 */
-	if (str_format == UUID_STR_FORMAT_STD)
+	if (str_format & UUID_STR_FORMAT_GUID)
-		char_order = uuid_char_order;
-	else
 		char_order = guid_char_order;
+	else
+		char_order = uuid_char_order;
+	if (str_format & UUID_STR_UPPER_CASE)
+		format = "%02X";
+	else
+		format = "%02x";
 
 	for (i = 0; i < 16; i++) {
-		sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]);
+		sprintf(uuid_str, format, uuid_bin[char_order[i]]);
 		uuid_str += 2;
 		switch (i) {
 		case 3:

lib/vsprintf.c

@@ -383,29 +383,31 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
 
 #ifdef CONFIG_LIB_UUID
 /*
- * This works (roughly) the same way as linux's, but we currently always
+ * This works (roughly) the same way as Linux's.
- * print lower-case (ie. we just keep %pUB and %pUL for compat with linux),
- * mostly just because that is what uuid_bin_to_str() supports.
  *
  *   %pUb:   01020304-0506-0708-090a-0b0c0d0e0f10
+ *   %pUB:   01020304-0506-0708-090A-0B0C0D0E0F10
  *   %pUl:   04030201-0605-0807-090a-0b0c0d0e0f10
+ *   %pUL:   04030201-0605-0807-090A-0B0C0D0E0F10
  */
 static char *uuid_string(char *buf, char *end, u8 *addr, int field_width,
 			 int precision, int flags, const char *fmt)
 {
 	char uuid[UUID_STR_LEN + 1];
-	int str_format = UUID_STR_FORMAT_STD;
+	int str_format;
 
 	switch (*(++fmt)) {
 	case 'L':
+		str_format = UUID_STR_FORMAT_GUID | UUID_STR_UPPER_CASE;
+		break;
 	case 'l':
 		str_format = UUID_STR_FORMAT_GUID;
 		break;
 	case 'B':
-	case 'b':
+		str_format = UUID_STR_FORMAT_STD | UUID_STR_UPPER_CASE;
-		/* this is the default */
 		break;
 	default:
+		str_format = UUID_STR_FORMAT_STD;
 		break;
 	}
 

test/print_ut.c

@@ -15,6 +15,26 @@
 #define FAKE_BUILD_TAG	"jenkins-u-boot-denx_uboot_dm-master-build-aarch64" \
 			"and a lot more text to come"
 
+/* Test printing GUIDs */
+static void guid_ut_print(void)
+{
+#if CONFIG_IS_ENABLED(LIB_UUID)
+	unsigned char guid[16] = {
+		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
+	};
+	char str[40];
+
+	sprintf(str, "%pUb", guid);
+	assert(!strcmp("01020304-0506-0708-090a-0b0c0d0e0f10", str));
+	sprintf(str, "%pUB", guid);
+	assert(!strcmp("01020304-0506-0708-090A-0B0C0D0E0F10", str));
+	sprintf(str, "%pUl", guid);
+	assert(!strcmp("04030201-0605-0807-090a-0b0c0d0e0f10", str));
+	sprintf(str, "%pUL", guid);
+	assert(!strcmp("04030201-0605-0807-090A-0B0C0D0E0F10", str));
+#endif
+}
+
 /* Test efi_loader specific printing */
 static void efi_ut_print(void)
 {
@@ -117,6 +137,9 @@ static int do_ut_print(cmd_tbl_t *cmdtp, int flag, int argc,
 	/* Test efi_loader specific printing */
 	efi_ut_print();
 
+	/* Test printing GUIDs */
+	guid_ut_print();
+
 	printf("%s: Everything went swimmingly\n", __func__);
 	return 0;
 }