1 // This file determines MIPS features a processor supports.
2 //
3 // We return:
4 // - 0 if the machine matches the asked-for feature.
5 // - 1 if the machine does not.
6 // - 2 if the asked-for feature isn't recognised (this will be the case for
7 // any feature if run on a non-MIPS machine).
8 // - 3 if there was a usage error (it also prints an error message).
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <assert.h>
13
14 #define FEATURE_PRESENT 0
15 #define FEATURE_NOT_PRESENT 1
16 #define UNRECOGNISED_FEATURE 2
17 #define USAGE_ERROR 3
18
19 #if defined(VGA_mips32) || defined(VGA_mips64)
mipsCPUInfo(const char * search_string)20 static int mipsCPUInfo(const char *search_string) {
21 const char *file_name = "/proc/cpuinfo";
22 /* Simple detection of MIPS DSP ASE at runtime for Linux.
23 * It is based on /proc/cpuinfo, which reveals hardware configuration
24 * to user-space applications. */
25
26 char cpuinfo_line[256];
27
28 FILE *f = NULL;
29 if ((f = fopen (file_name, "r")) == NULL)
30 return 0;
31
32 while (fgets (cpuinfo_line, sizeof (cpuinfo_line), f) != NULL)
33 {
34 if (strstr (cpuinfo_line, search_string) != NULL)
35 {
36 fclose (f);
37 return 1;
38 }
39 }
40
41 fclose (f);
42
43 /* Did not find string in the /proc/cpuinfo file. */
44 return 0;
45 }
46
go(char * feature)47 static int go(char *feature)
48 {
49 int cpuinfo;
50 if (strcmp(feature, "fpu") == 0) {
51 #if defined(__mips_hard_float)
52 /* This is not a runtime detection.
53 If mips_features is built as hard-float, the assumption is that
54 the target MIPS platform has a floating-point unit. */
55 return FEATURE_PRESENT;
56 #else
57 return FEATURE_NOT_PRESENT;
58 #endif
59 } else if (strcmp(feature, "mips-msa") == 0) {
60 const char *msa = "msa";
61 cpuinfo = mipsCPUInfo(msa);
62 if (cpuinfo == 1) {
63 return FEATURE_PRESENT;
64 } else{
65 return FEATURE_NOT_PRESENT;
66 }
67 } else if (strcmp(feature, "mips32-dsp") == 0) {
68 const char *dsp = "dsp";
69 cpuinfo = mipsCPUInfo(dsp);
70 if (cpuinfo == 1) {
71 return FEATURE_PRESENT;
72 } else{
73 return FEATURE_NOT_PRESENT;
74 }
75 } else if (strcmp(feature, "mips32-dspr2") == 0) {
76 const char *dsp2 = "dsp2";
77 cpuinfo = mipsCPUInfo(dsp2);
78 if (cpuinfo == 1) {
79 return FEATURE_PRESENT;
80 } else{
81 return FEATURE_NOT_PRESENT;
82 }
83 } else if (strcmp(feature, "cavium-octeon") == 0) {
84 const char *cavium = "Cavium Octeon";
85 cpuinfo = mipsCPUInfo(cavium);
86 if (cpuinfo == 1) {
87 return FEATURE_PRESENT;
88 } else{
89 return FEATURE_NOT_PRESENT;
90 }
91 } else if (strcmp(feature, "cavium-octeon2") == 0) {
92 const char *cavium2 = "Cavium Octeon II";
93 cpuinfo = mipsCPUInfo(cavium2);
94 if (cpuinfo == 1) {
95 return FEATURE_PRESENT;
96 } else{
97 return FEATURE_NOT_PRESENT;
98 }
99 } else if (strcmp(feature, "mips-be") == 0) {
100 #if defined (_MIPSEB)
101 return FEATURE_PRESENT;
102 #else
103 return FEATURE_NOT_PRESENT;
104 #endif
105 } else if (strcmp(feature, "mipsr6") == 0) {
106 #if (__mips_isa_rev < 6)
107 return FEATURE_NOT_PRESENT;
108 #else
109 return FEATURE_PRESENT;
110 #endif
111 } else {
112 return UNRECOGNISED_FEATURE;
113 }
114
115 }
116
117 #else
118
go(char * feature)119 static int go(char *feature)
120 {
121 /* Feature is not recognised. (non-MIPS machine!) */
122 return UNRECOGNISED_FEATURE;
123 }
124
125 #endif
126
127
128 //---------------------------------------------------------------------------
129 // main
130 //---------------------------------------------------------------------------
main(int argc,char ** argv)131 int main(int argc, char **argv)
132 {
133 if (argc != 2) {
134 fprintf( stderr, "usage: mips_features <feature>\n" );
135 exit(USAGE_ERROR);
136 }
137 return go(argv[1]);
138 }
139