1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * stdlib functions
4 *
5 * Author: Scott Wood <scottwood@freescale.com>
6 *
7 * Copyright (c) 2007 Freescale Semiconductor, Inc.
8 */
9
10#include "stdlib.h"
11
12/* Not currently supported: leading whitespace, sign, 0x prefix, zero base */
13unsigned long long int strtoull(const char *ptr, char **end, int base)
14{
15	unsigned long long ret = 0;
16
17	if (base > 36)
18		goto out;
19
20	while (*ptr) {
21		int digit;
22
23		if (*ptr >= '0' && *ptr <= '9' && *ptr < '0' + base)
24			digit = *ptr - '0';
25		else if (*ptr >= 'A' && *ptr < 'A' + base - 10)
26			digit = *ptr - 'A' + 10;
27		else if (*ptr >= 'a' && *ptr < 'a' + base - 10)
28			digit = *ptr - 'a' + 10;
29		else
30			break;
31
32		ret *= base;
33		ret += digit;
34		ptr++;
35	}
36
37out:
38	if (end)
39		*end = (char *)ptr;
40
41	return ret;
42}
43