• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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