1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2003
4  * Tait Electronics Limited, Christchurch, New Zealand
5  */
6 
7 /*
8  * This file provides a shell like 'test' function to return
9  * true/false from an integer or string compare of two memory
10  * locations or a location and a scalar/literal.
11  * A few parts were lifted from bash 'test' command
12  */
13 
14 #include <common.h>
15 #include <config.h>
16 #include <command.h>
17 #include <mapmem.h>
18 
19 #include <asm/io.h>
20 
21 #define EQ	0
22 #define NE	1
23 #define LT	2
24 #define GT	3
25 #define LE	4
26 #define GE	5
27 
28 struct op_tbl_s {
29 	char	*op;		/* operator string */
30 	int	opcode;		/* internal representation of opcode */
31 };
32 
33 typedef struct op_tbl_s op_tbl_t;
34 
35 static const op_tbl_t op_table [] = {
36 	{ "-lt", LT },
37 	{ "<"  , LT },
38 	{ "-gt", GT },
39 	{ ">"  , GT },
40 	{ "-eq", EQ },
41 	{ "==" , EQ },
42 	{ "-ne", NE },
43 	{ "!=" , NE },
44 	{ "<>" , NE },
45 	{ "-ge", GE },
46 	{ ">=" , GE },
47 	{ "-le", LE },
48 	{ "<=" , LE },
49 };
50 
evalexp(char * s,int w)51 static long evalexp(char *s, int w)
52 {
53 	long l = 0;
54 	unsigned long addr;
55 	void *buf;
56 
57 	/* if the parameter starts with a * then assume is a pointer to the value we want */
58 	if (s[0] == '*') {
59 		addr = simple_strtoul(&s[1], NULL, 16);
60 		buf = map_physmem(addr, w, MAP_WRBACK);
61 		if (!buf && addr) {
62 			puts("Failed to map physical memory\n");
63 			return 0;
64 		}
65 		switch (w) {
66 		case 1:
67 			l = (long)(*(u8 *)buf);
68 			break;
69 		case 2:
70 			l = (long)(*(u16 *)buf);
71 			break;
72 		case 4:
73 			l = (long)(*(u32 *)buf);
74 			break;
75 		}
76 		unmap_physmem(buf, w);
77 		return l;
78 	} else {
79 		l = simple_strtoul(s, NULL, 16);
80 	}
81 
82 	/* avoid overflow on mask calculus */
83 	return (w >= sizeof(long)) ? l : (l & ((1UL << (w * 8)) - 1));
84 }
85 
evalstr(char * s)86 static char * evalstr(char *s)
87 {
88 	/* if the parameter starts with a * then assume a string pointer else its a literal */
89 	if (s[0] == '*') {
90 		return (char *)simple_strtoul(&s[1], NULL, 16);
91 	} else if (s[0] == '$') {
92 		int i = 2;
93 
94 		if (s[1] != '{')
95 			return NULL;
96 
97 		while (s[i] != '}') {
98 			if (s[i] == 0)
99 				return NULL;
100 			i++;
101 		}
102 		s[i] = 0;
103 		return  env_get((const char *)&s[2]);
104 	} else {
105 		return s;
106 	}
107 }
108 
stringcomp(char * s,char * t,int op)109 static int stringcomp(char *s, char *t, int op)
110 {
111 	int p;
112 	char *l, *r;
113 
114 	l = evalstr(s);
115 	r = evalstr(t);
116 
117 	p = strcmp(l, r);
118 	switch (op) {
119 	case EQ: return (p == 0);
120 	case NE: return (p != 0);
121 	case LT: return (p < 0);
122 	case GT: return (p > 0);
123 	case LE: return (p <= 0);
124 	case GE: return (p >= 0);
125 	}
126 	return (0);
127 }
128 
arithcomp(char * s,char * t,int op,int w)129 static int arithcomp (char *s, char *t, int op, int w)
130 {
131 	long l, r;
132 
133 	l = evalexp (s, w);
134 	r = evalexp (t, w);
135 
136 	switch (op) {
137 	case EQ: return (l == r);
138 	case NE: return (l != r);
139 	case LT: return (l < r);
140 	case GT: return (l > r);
141 	case LE: return (l <= r);
142 	case GE: return (l >= r);
143 	}
144 	return (0);
145 }
146 
binary_test(char * op,char * arg1,char * arg2,int w)147 static int binary_test(char *op, char *arg1, char *arg2, int w)
148 {
149 	int len, i;
150 	const op_tbl_t *optp;
151 
152 	len = strlen(op);
153 
154 	for (optp = (op_tbl_t *)&op_table, i = 0;
155 	     i < ARRAY_SIZE(op_table);
156 	     optp++, i++) {
157 
158 		if ((strncmp (op, optp->op, len) == 0) && (len == strlen (optp->op))) {
159 			if (w == 0) {
160 				return (stringcomp(arg1, arg2, optp->opcode));
161 			} else {
162 				return (arithcomp (arg1, arg2, optp->opcode, w));
163 			}
164 		}
165 	}
166 
167 	printf("Unknown operator '%s'\n", op);
168 	return 0;	/* op code not found */
169 }
170 
171 /* command line interface to the shell test */
do_itest(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])172 static int do_itest(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
173 {
174 	int	value, w;
175 
176 	/* Validate arguments */
177 	if ((argc != 4))
178 		return CMD_RET_USAGE;
179 
180 	/* Check for a data width specification.
181 	 * Defaults to long (4) if no specification.
182 	 * Uses -2 as 'width' for .s (string) so as not to upset existing code
183 	 */
184 	switch (w = cmd_get_data_size(argv[0], 4)) {
185 	case 1:
186 	case 2:
187 	case 4:
188 		value = binary_test (argv[2], argv[1], argv[3], w);
189 		break;
190 	case -2:
191 		value = binary_test (argv[2], argv[1], argv[3], 0);
192 		break;
193 	case -1:
194 	default:
195 		puts("Invalid data width specifier\n");
196 		value = 0;
197 		break;
198 	}
199 
200 	return !value;
201 }
202 
203 U_BOOT_CMD(
204 	itest, 4, 0, do_itest,
205 	"return true/false on integer compare",
206 	"[.b, .w, .l, .s] [*]value1 <op> [*]value2"
207 );
208