tools/padjffs2/src/padjffs2.c

   1 /*
   2  * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <libgen.h>
  13 #include <stdio.h>
  14 #include <stdint.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20
  21 static char *progname;
  22 static unsigned int xtra_offset;
  23 static unsigned char eof_mark[4] = {0xde, 0xad, 0xc0, 0xde};
  24
  25 #define ERR(fmt, ...) do { \
  26         fflush(0); \
  27         fprintf(stderr, "[%s] *** error: " fmt "\n", \
  28                         progname, ## __VA_ARGS__ ); \
  29 } while (0)
  30
  31 #define ERRS(fmt, ...) do { \
  32         int save = errno; \
  33         fflush(0); \
  34         fprintf(stderr, "[%s] *** error: " fmt ", %s\n", \
  35                         progname, ## __VA_ARGS__, strerror(save)); \
  36 } while (0)
  37
  38 #define BUF_SIZE        (64 * 1024)
  39 #define ALIGN(_x,_y)    (((_x) + ((_y) - 1)) & ~((_y) - 1))
  40
  41 static int pad_image(char *name, uint32_t pad_mask)
  42 {
  43         char *buf;
  44         int fd;
  45         ssize_t in_len;
  46         ssize_t out_len;
  47         int ret = -1;
  48
  49         buf = malloc(BUF_SIZE);
  50         if (!buf) {
  51                 ERR("No memory for buffer");
  52                 goto out;
  53         }
  54
  55         fd = open(name, O_RDWR);
  56         if (fd < 0) {
  57                 ERRS("Unable to open %s", name);
  58                 goto free_buf;
  59         }
  60
  61         in_len = lseek(fd, 0, SEEK_END);
  62         if (in_len < 0)
  63                 goto close;
  64
  65         memset(buf, '\xff', BUF_SIZE);
  66
  67         in_len += xtra_offset;
  68
  69         out_len = in_len;
  70         while (pad_mask) {
  71                 uint32_t mask;
  72                 ssize_t t;
  73                 int i;
  74
  75                 for (i = 10; i < 32; i++) {
  76                         mask = 1UL << i;
  77                         if (pad_mask & mask)
  78                                 break;
  79                 }
  80
  81                 in_len = ALIGN(in_len, mask);
  82
  83                 for (i = 10; i < 32; i++) {
  84                         mask = 1UL << i;
  85                         if ((in_len & (mask - 1)) == 0)
  86                                 pad_mask &= ~mask;
  87                 }
  88
  89                 printf("padding image to %08x\n", (unsigned int) in_len - xtra_offset);
  90
  91                 while (out_len < in_len) {
  92                         ssize_t len;
  93
  94                         len = in_len - out_len;
  95                         if (len > BUF_SIZE)
  96                                 len = BUF_SIZE;
  97
  98                         t = write(fd, buf, len);
  99                         if (t != len) {
 100                                 ERRS("Unable to write to %s", name);
 101                                 goto close;
 102                         }
 103
 104                         out_len += len;
 105                 }
 106
 107                 /* write out the JFFS end-of-filesystem marker */
 108                 t = write(fd, eof_mark, 4);
 109                 if (t != 4) {
 110                         ERRS("Unable to write to %s", name);
 111                         goto close;
 112                 }
 113                 out_len += 4;
 114         }
 115
 116         ret = 0;
 117
 118 close:
 119         close(fd);
 120 free_buf:
 121         free(buf);
 122 out:
 123         return ret;
 124 }
 125
 126 int main(int argc, char* argv[])
 127 {
 128         uint32_t pad_mask;
 129         int ret = EXIT_FAILURE;
 130         int err;
 131         int i;
 132
 133         progname = basename(argv[0]);
 134
 135         if (argc < 2) {
 136                 fprintf(stderr,
 137                         "Usage: %s file [-x <xtra offset>] [pad0] [pad1] [padN]\n",
 138                         progname);
 139                 goto out;
 140         }
 141
 142         pad_mask = 0;
 143         for (i = 2; i < argc; i++) {
 144                 if (i == 2 && strcmp(argv[i], "-x") == 0) {
 145                         i++;
 146                         xtra_offset = strtoul(argv[i], NULL, 0);
 147                         fprintf(stderr, "assuming %u bytes offset\n",
 148                                 xtra_offset);
 149                         continue;
 150                 }
 151                 pad_mask |= strtoul(argv[i], NULL, 0) * 1024;
 152         }
 153
 154         if (pad_mask == 0)
 155                 pad_mask = (4 * 1024) | (8 * 1024) | (64 * 1024) |
 156                            (128 * 1024);
 157
 158         err = pad_image(argv[1], pad_mask);
 159         if (err)
 160                 goto out;
 161
 162         ret = EXIT_SUCCESS;
 163
 164 out:
 165         return ret;
 166 }