lib: Add a function to convert a string to a hex value

Add an xtoa() function, similar to itoa() but for hex instead.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
Tested-by: Artem Lapkin <email2tema@gmail.com>

include/vsprintf.h

@@ -177,14 +177,26 @@ int vsprintf(char *buf, const char *fmt, va_list args);
  * simple_itoa() - convert an unsigned integer to a string
  *
  * This returns a static string containing the decimal representation of the
- * given value. The returned value may be overwritten by other calls to the
+ * given value. The returned value may be overwritten by other calls to other
- * same function, so should be used immediately
+ * simple_... functions, so should be used immediately
  *
  * @val: Value to convert
  * @return string containing the decimal representation of @val
  */
 char *simple_itoa(ulong val);
 
+/**
+ * simple_xtoa() - convert an unsigned integer to a hex string
+ *
+ * This returns a static string containing the hexadecimal representation of the
+ * given value. The returned value may be overwritten by other calls to other
+ * simple_... functions, so should be used immediately
+ *
+ * @val: Value to convert
+ * @return string containing the hexecimal representation of @val
+ */
+char *simple_xtoa(ulong num);
+
 /**
  * Format a string and place it in a buffer
  *

lib/vsprintf.c

@@ -816,11 +816,12 @@ int vprintf(const char *fmt, va_list args)
 }
 #endif
 
+static char local_toa[22];
+
 char *simple_itoa(ulong i)
 {
 	/* 21 digits plus null terminator, good for 64-bit or smaller ints */
-	static char local[22];
+	char *p = &local_toa[21];
-	char *p = &local[21];
 
 	*p-- = '\0';
 	do {
@@ -830,6 +831,21 @@ char *simple_itoa(ulong i)
 	return p + 1;
 }
 
+char *simple_xtoa(ulong num)
+{
+	/* 16 digits plus nul terminator, good for 64-bit or smaller ints */
+	char *p = &local_toa[17];
+
+	*--p = '\0';
+	do {
+		p -= 2;
+		hex_byte_pack(p, num & 0xff);
+		num >>= 8;
+	} while (num > 0);
+
+	return p;
+}
+
 /* We don't seem to have %'d in U-Boot */
 void print_grouped_ull(unsigned long long int_val, int digits)
 {

test/print_ut.c

@@ -335,16 +335,40 @@ static int print_itoa(struct unit_test_state *uts)
 	ut_asserteq_str("0", simple_itoa(0));
 	ut_asserteq_str("2147483647", simple_itoa(0x7fffffff));
 	ut_asserteq_str("4294967295", simple_itoa(0xffffffff));
+
+	/* Use #ifdef here to avoid a compiler warning on 32-bit machines */
+#ifdef CONFIG_PHYS_64BIT
 	if (sizeof(ulong) == 8) {
 		ut_asserteq_str("9223372036854775807",
 				simple_itoa((1UL << 63) - 1));
 		ut_asserteq_str("18446744073709551615", simple_itoa(-1));
 	}
+#endif /* CONFIG_PHYS_64BIT */
 
 	return 0;
 }
 PRINT_TEST(print_itoa, 0);
 
+static int print_xtoa(struct unit_test_state *uts)
+{
+	ut_asserteq_str("7f", simple_xtoa(127));
+	ut_asserteq_str("00", simple_xtoa(0));
+	ut_asserteq_str("7fffffff", simple_xtoa(0x7fffffff));
+	ut_asserteq_str("ffffffff", simple_xtoa(0xffffffff));
+
+	/* Use #ifdef here to avoid a compiler warning on 32-bit machines */
+#ifdef CONFIG_PHYS_64BIT
+	if (sizeof(ulong) == 8) {
+		ut_asserteq_str("7fffffffffffffff",
+				simple_xtoa((1UL << 63) - 1));
+		ut_asserteq_str("ffffffffffffffff", simple_xtoa(-1));
+	}
+#endif /* CONFIG_PHYS_64BIT */
+
+	return 0;
+}
+PRINT_TEST(print_xtoa, 0);
+
 int do_ut_print(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	struct unit_test *tests = UNIT_TEST_SUITE_START(print_test);