ref: b502a62da2ec6058923db94f87ecc2d29db2fa77
dir: /os/boot.original/pc/fs.c/
#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "fs.h" /* * grab next element from a path, return the pointer to unprocessed portion of * path. */ char * nextelem(char *path, char *elem) { int i; while(*path == '/') path++; if(*path==0 || *path==' ') return 0; for(i=0; *path!='\0' && *path!='/' && *path!=' '; i++){ if(i==NAMELEN){ print("name component too long\n"); return 0; } *elem++ = *path++; } *elem = '\0'; return path; } int fswalk(Fs *fs, char *path, File *f) { char element[NAMELEN]; *f = fs->root; if(BADPTR(fs->walk)) panic("fswalk bad pointer fs->walk"); f->path = path; while(path = nextelem(path, element)){ switch(fs->walk(f, element)){ case -1: return -1; case 0: return 0; } } return 1; } /* * boot */ int fsboot(Fs *fs, char *path, Boot *b) { File file; long n; static char buf[8192]; switch(fswalk(fs, path, &file)){ case -1: print("error walking to %s\n", path); return -1; case 0: print("%s not found\n", path); return -1; case 1: print("found %s\n", path); break; } while((n = fsread(&file, buf, sizeof buf)) > 0) { if(bootpass(b, buf, n) != MORE) break; } bootpass(b, nil, 0); /* tries boot */ return -1; } int fsread(File *file, void *a, long n) { if(BADPTR(file->fs)) panic("bad pointer file->fs in fsread"); if(BADPTR(file->fs->read)) panic("bad pointer file->fs->read in fsread"); return file->fs->read(file, a, n); }