vfs.txt (1861B)
1 $Id: //depot/blt/doc/vfs.txt#4 $ 2 3 Documentation for the OpenBLT Virtual Filesystem 4 ------------------------------------------------ 5 6 This documentation is Copyright 1999 Sidney Cammeresi. All rights reserved. 7 8 9 10 Contents 11 -------- 12 1. Overview 13 2. File descriptor layer 14 3. Vnode layer 15 4. Filesystem layer 16 17 5. VFS server message protocol 18 19 20 1. Overview 21 ----------- 22 23 24 25 2. File descriptor layer 26 ------------------------ 27 28 This layer is not written yet. 29 30 31 32 3. Vnode layer 33 -------------- 34 35 36 37 4. Filesystem layer 38 ------------------- 39 40 41 42 5. VFS server message protocol 43 ------------------------------ 44 45 vfs command and return parameters (a.k.a. data[] contents) 46 47 48 static symbols are for use by libc only! 49 50 51 static void __vfs_openconn (int src_port, int dest_port, int filename_area); 52 ============================================================================ 53 0 filename area 54 55 0 private port for talking to vfs 56 57 static void __vfs_scroll_area (int fd, int offset) 58 ================================================== 59 0 vfs file descriptor 60 1 new offset (in bytes for file, dirents for directory) 61 62 0 number of bytes copied 63 1 more? 64 65 DIR *opendir (const char *dir) 66 ============================== 67 0 filename offset 68 1 payload area id 69 2 payload offset 70 3 payload length 71 72 0 vfs file descriptor 73 1 number of dirents in shmem 74 2 more? 75 76 int closedir (DIR *dirp) 77 ======================== 78 0 vfs file descriptor 79 80 no output data 81 82 int open (const char *path, int flags, mode_t mode) 83 =================================================== 84 0 filename offset 85 1 payload area id 86 2 payload offset 87 3 payload length 88 89 0 vfs file descriptor 90 1 length of data in shmem 91 2 more? 92 93 int stat (const char *path, struct stat *buf) 94 ============================================= 95 0 filename offset 96 97 no output data, but a (struct stat) follows the vfs_res_t 98