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 }
60 else if (strcmp(feature, "mips32-dsp") == 0) {
61 const char *dsp = "dsp";
62 cpuinfo = mipsCPUInfo(dsp);
63 if (cpuinfo == 1) {
64 return FEATURE_PRESENT;
65 } else{
66 return FEATURE_NOT_PRESENT;
67 }
68 } else if (strcmp(feature, "mips32-dspr2") == 0) {
69 const char *dsp2 = "dsp2";
70 cpuinfo = mipsCPUInfo(dsp2);
71 if (cpuinfo == 1) {
72 return FEATURE_PRESENT;
73 } else{
74 return FEATURE_NOT_PRESENT;
75 }
76 } else if (strcmp(feature, "cavium-octeon") == 0) {
77 const char *cavium = "Cavium Octeon";
78 cpuinfo = mipsCPUInfo(cavium);
79 if (cpuinfo == 1) {
80 return FEATURE_PRESENT;
81 } else{
82 return FEATURE_NOT_PRESENT;
83 }
84 } else if (strcmp(feature, "cavium-octeon2") == 0) {
85 const char *cavium2 = "Cavium Octeon II";
86 cpuinfo = mipsCPUInfo(cavium2);
87 if (cpuinfo == 1) {
88 return FEATURE_PRESENT;
89 } else{
90 return FEATURE_NOT_PRESENT;
91 }
92 } else if (strcmp(feature, "mips-be") == 0) {
93 #if defined (_MIPSEB)
94 return FEATURE_PRESENT;
95 #else
96 return FEATURE_NOT_PRESENT;
97 #endif
98 } else {
99 return UNRECOGNISED_FEATURE;
100 }
101
102 }
103
104 #else
105
go(char * feature)106 static int go(char *feature)
107 {
108 /* Feature is not recognised. (non-MIPS machine!) */
109 return UNRECOGNISED_FEATURE;
110 }
111
112 #endif
113
114
115 //---------------------------------------------------------------------------
116 // main
117 //---------------------------------------------------------------------------
main(int argc,char ** argv)118 int main(int argc, char **argv)
119 {
120 if (argc != 2) {
121 fprintf( stderr, "usage: mips_features <feature>\n" );
122 exit(USAGE_ERROR);
123 }
124 return go(argv[1]);
125 }
126