1 /*
2  * (C) Copyright 2003
3  * Tait Electronics Limited, Christchurch, New Zealand
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 /*
25  * This file provides a shell like 'test' function to return
26  * true/false from an integer or string compare of two memory
27  * locations or a location and a scalar/literal.
28  * A few parts were lifted from bash 'test' command
29  */
30 
31 #include <common.h>
32 #include <config.h>
33 #include <command.h>
34 
35 #define EQ	0
36 #define NE	1
37 #define LT	2
38 #define GT	3
39 #define LE	4
40 #define GE	5
41 
42 struct op_tbl_s {
43 	char	*op;		/* operator string */
44 	int	opcode;		/* internal representation of opcode */
45 };
46 
47 typedef struct op_tbl_s op_tbl_t;
48 
49 op_tbl_t op_table [] = {
50 	{ "-lt", LT },
51 	{ "<"  , LT },
52 	{ "-gt", GT },
53 	{ ">"  , GT },
54 	{ "-eq", EQ },
55 	{ "==" , EQ },
56 	{ "-ne", NE },
57 	{ "!=" , NE },
58 	{ "<>" , NE },
59 	{ "-ge", GE },
60 	{ ">=" , GE },
61 	{ "-le", LE },
62 	{ "<=" , LE },
63 };
64 
65 #define op_tbl_size (sizeof(op_table)/sizeof(op_table[0]))
66 
evalexp(char * s,int w)67 static long evalexp(char *s, int w)
68 {
69 	long l = 0;
70 	long *p;
71 
72 	/* if the parameter starts with a * then assume is a pointer to the value we want */
73 	if (s[0] == '*') {
74 		p = (long *)simple_strtoul(&s[1], NULL, 16);
75 		switch (w) {
76 		case 1: return((long)(*(unsigned char *)p));
77 		case 2: return((long)(*(unsigned short *)p));
78 		case 4: return(*p);
79 		}
80 	} else {
81 		l = simple_strtoul(s, NULL, 16);
82 	}
83 
84 	return (l & ((1 << (w * 8)) - 1));
85 }
86 
evalstr(char * s)87 static char * evalstr(char *s)
88 {
89 	/* if the parameter starts with a * then assume a string pointer else its a literal */
90 	if (s[0] == '*') {
91 		return (char *)simple_strtoul(&s[1], NULL, 16);
92 	} else {
93 		return s;
94 	}
95 }
96 
stringcomp(char * s,char * t,int op)97 static int stringcomp(char *s, char *t, int op)
98 {
99 	int n, p;
100 	char *l, *r;
101 
102 	l = evalstr(s);
103 	r = evalstr(t);
104 
105 	/* we'll do a compare based on the length of the shortest string */
106 	n = min(strlen(l), strlen(r));
107 
108 	p = strncmp(l, r, n);
109 	switch (op) {
110 	case EQ: return (p == 0);
111 	case NE: return (p != 0);
112 	case LT: return (p < 0);
113 	case GT: return (p > 0);
114 	case LE: return (p <= 0);
115 	case GE: return (p >= 0);
116 	}
117 	return (0);
118 }
119 
arithcomp(char * s,char * t,int op,int w)120 static int arithcomp (char *s, char *t, int op, int w)
121 {
122 	long l, r;
123 
124 	l = evalexp (s, w);
125 	r = evalexp (t, w);
126 
127 	switch (op) {
128 	case EQ: return (l == r);
129 	case NE: return (l != r);
130 	case LT: return (l < r);
131 	case GT: return (l > r);
132 	case LE: return (l <= r);
133 	case GE: return (l >= r);
134 	}
135 	return (0);
136 }
137 
binary_test(char * op,char * arg1,char * arg2,int w)138 int binary_test (char *op, char *arg1, char *arg2, int w)
139 {
140 	int len, i;
141 	op_tbl_t *optp;
142 
143 	len = strlen(op);
144 
145 	for (optp = (op_tbl_t *)&op_table, i = 0;
146 	     i < op_tbl_size;
147 	     optp++, i++) {
148 
149 		if ((strncmp (op, optp->op, len) == 0) && (len == strlen (optp->op))) {
150 			if (w == 0) {
151 				return (stringcomp(arg1, arg2, optp->opcode));
152 			} else {
153 				return (arithcomp (arg1, arg2, optp->opcode, w));
154 			}
155 		}
156 	}
157 
158 	printf("Unknown operator '%s'\n", op);
159 	return 0;	/* op code not found */
160 }
161 
162 /* command line interface to the shell test */
do_itest(cmd_tbl_t * cmdtp,int flag,int argc,char * argv[])163 int do_itest ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[] )
164 {
165 	int	value, w;
166 
167 	/* Validate arguments */
168 	if ((argc != 4)){
169 		cmd_usage(cmdtp);
170 		return 1;
171 	}
172 
173 	/* Check for a data width specification.
174 	 * Defaults to long (4) if no specification.
175 	 * Uses -2 as 'width' for .s (string) so as not to upset existing code
176 	 */
177 	switch (w = cmd_get_data_size(argv[0], 4)) {
178 	case 1:
179 	case 2:
180 	case 4:
181 		value = binary_test (argv[2], argv[1], argv[3], w);
182 		break;
183 	case -2:
184 		value = binary_test (argv[2], argv[1], argv[3], 0);
185 		break;
186 	case -1:
187 	default:
188 		puts("Invalid data width specifier\n");
189 		value = 0;
190 		break;
191 	}
192 
193 	return !value;
194 }
195 
196 U_BOOT_CMD(
197 	itest, 4, 0, do_itest,
198 	"return true/false on integer compare",
199 	"[.b, .w, .l, .s] [*]value1 <op> [*]value2"
200 );
201