ref: b8986a889d7e3a445c0265c5cfb3b1db385db756
dir: /sys/src/cmd/bitsy/params.c/
#include <u.h> #include <libc.h> void erase(char *part) { char file[256]; int fd; snprint(file, sizeof file, "%sctl", part); fd = open(file, ORDWR); if(fd < 0) return; fprint(fd, "erase"); close(fd); } char* readfile(char *file) { char buf[512]; int n, fd; uchar *p; fd = open(file, OREAD); if(fd < 0) sysfatal("opening %s: %r", file); n = read(fd, buf, sizeof(buf)-1); close(fd); if(n < 0) return ""; buf[n] = 0; for(p = (uchar*)buf; *p; p++) if(*p == 0xff){ *p = 0; break; } return strdup(buf); } void writefile(char *file, char *data) { int fd; fd = open(file, OWRITE); if(fd < 0) fd = create(file, OWRITE, 0664); if(fd < 0) return; write(fd, data, strlen(data)); close(fd); } void main(int argc, char **argv) { int from = 0; char *params; char *file = "/tmp/tmpparams"; char *part; ARGBEGIN { case 'f': from++; break; } ARGEND; if(argc) part = argv[0]; else part = "/dev/flash/user"; if(from){ params = readfile(part); writefile(file, params); } else { params = readfile(file); erase(part); writefile(part, params); free(params); } }