sys/src/cmd/bitsy/params.c

   1 #include <u.h>
   2 #include <libc.h>
   3
   4 void
   5 erase(char *part)
   6 {
   7         char file[256];
   8         int fd;
   9
  10         snprint(file, sizeof file, "%sctl", part);
  11         fd = open(file, ORDWR);
  12         if(fd < 0)
  13                 return;
  14         fprint(fd, "erase");
  15         close(fd);
  16 }
  17
  18 char*
  19 readfile(char *file)
  20 {
  21         char buf[512];
  22         int n, fd;
  23         uchar *p;
  24
  25         fd = open(file, OREAD);
  26         if(fd < 0)
  27                 sysfatal("opening %s: %r", file);
  28         n = read(fd, buf, sizeof(buf)-1);
  29         close(fd);
  30         if(n < 0)
  31                 return "";
  32         buf[n] = 0;
  33         for(p = (uchar*)buf; *p; p++)
  34                 if(*p == 0xff){
  35                         *p = 0;
  36                         break;
  37                 }
  38         return strdup(buf);
  39 }
  40
  41 void
  42 writefile(char *file, char *data)
  43 {
  44         int fd;
  45
  46         fd = open(file, OWRITE);
  47         if(fd < 0)
  48                 fd = create(file, OWRITE, 0664);
  49         if(fd < 0)
  50                 return;
  51         write(fd, data, strlen(data));
  52         close(fd);
  53 }
  54
  55 void
  56 main(int argc, char **argv)
  57 {
  58         int from = 0;
  59         char *params;
  60         char *file = "/tmp/tmpparams";
  61         char *part;
  62
  63         ARGBEGIN {
  64         case 'f':
  65                 from++;
  66                 break;
  67         } ARGEND;
  68
  69         if(argc)
  70                 part = argv[0];
  71         else
  72                 part = "/dev/flash/user";
  73
  74         if(from){
  75                 params = readfile(part);
  76                 writefile(file, params);
  77         } else {
  78                 params = readfile(file);
  79                 erase(part);
  80                 writefile(part, params);
  81                 free(params);
  82         }
  83 }