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 */
strtoull(const char * ptr,char ** end,int base)13 unsigned 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 
37 out:
38 	if (end)
39 		*end = (char *)ptr;
40 
41 	return ret;
42 }
43