git.zerfleddert.de Git - hmcfgusb/blob - firmware.c

   1 /* generic firmware-functions for HomeMatic
   2  *
   3  * Copyright (c) 2014 Michael Gernoth <michael@gernoth.net>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to
   7  * deal in the Software without restriction, including without limitation the
   8  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   9  * sell copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <stdint.h>
  28 #include <string.h>
  29 #include <strings.h>
  30 #include <errno.h>
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <fcntl.h>
  34 #include <sys/time.h>
  35
  36 #include "firmware.h"
  37
  38 /* This might be wrong, but it works for current fw */
  39 #define MAX_BLOCK_LENGTH        512
  40
  41 static uint8_t ascii_to_nibble(uint8_t a)
  42 {
  43         uint8_t c = 0x00;
  44
  45         if ((a >= '0') && (a <= '9')) {
  46                 c = a - '0';
  47         } else if ((a >= 'A') && (a <= 'F')) {
  48                 c = (a - 'A') + 10;
  49         } else if ((a >= 'a') && (a <= 'f')) {
  50                 c = (a - 'a') + 10;
  51         }
  52
  53         return c;
  54 }
  55
  56 static int validate_nibble(uint8_t a)
  57 {
  58         if (((a >= '0') && (a <= '9')) ||
  59             ((a >= 'A') && (a <= 'F')) ||
  60             ((a >= 'a') && (a <= 'f')))
  61                 return 1;
  62
  63         return 0;
  64 }
  65
  66 struct firmware* firmware_read_firmware(char *filename, int debug)
  67 {
  68         struct firmware *fw;
  69         struct stat stat_buf;
  70         uint8_t buf[4096];
  71         uint16_t len;
  72         int fd;
  73         int r;
  74         int i;
  75
  76         fw = malloc(sizeof(struct firmware));
  77         if (!fw) {
  78                 perror("malloc(fw)");
  79                 return NULL;
  80         }
  81
  82         memset(fw, 0, sizeof(struct firmware));
  83
  84         if (stat(filename, &stat_buf) == -1) {
  85                 fprintf(stderr, "Can't stat %s: %s\n", filename, strerror(errno));
  86                 exit(EXIT_FAILURE);
  87         }
  88
  89         fd = open(filename, O_RDONLY);
  90         if (fd < 0) {
  91                 fprintf(stderr, "Can't open %s: %s", filename, strerror(errno));
  92                 exit(EXIT_FAILURE);
  93         }
  94
  95         printf("Reading firmware from %s...\n", filename);
  96         do {
  97                 memset(buf, 0, sizeof(buf));
  98                 r = read(fd, buf, 4);
  99                 if (r < 0) {
 100                         perror("read");
 101                         exit(EXIT_FAILURE);
 102                 } else if (r == 0) {
 103                         break;
 104                 } else if (r != 4) {
 105                         printf("can't get length information!\n");
 106                         exit(EXIT_FAILURE);
 107                 }
 108
 109                 for (i = 0; i < r; i++) {
 110                         if (!validate_nibble(buf[i])) {
 111                                 fprintf(stderr, "Firmware file not valid!\n");
 112                                 exit(EXIT_FAILURE);
 113                         }
 114                 }
 115
 116                 len = (ascii_to_nibble(buf[0]) & 0xf)<< 4;
 117                 len |= ascii_to_nibble(buf[1]) & 0xf;
 118                 len <<= 8;
 119                 len |= (ascii_to_nibble(buf[2]) & 0xf)<< 4;
 120                 len |= ascii_to_nibble(buf[3]) & 0xf;
 121
 122                 /* This might be wrong, but it works for current fw->fw */
 123                 if (len > MAX_BLOCK_LENGTH) {
 124                         fprintf(stderr, "Invalid block-length %u > %u for block %d!\n", len, MAX_BLOCK_LENGTH, fw->fw_blocks+1);
 125                         exit(EXIT_FAILURE);
 126                 }
 127
 128                 fw->fw = realloc(fw->fw, sizeof(uint8_t*) * (fw->fw_blocks + 1));
 129                 if (fw->fw == NULL) {
 130                         perror("Can't reallocate fw->fw-blocklist");
 131                         exit(EXIT_FAILURE);
 132                 }
 133
 134                 fw->fw[fw->fw_blocks] = malloc(len + 4);
 135                 if (fw->fw[fw->fw_blocks] == NULL) {
 136                         perror("Can't allocate memory for fw->fw-block");
 137                         exit(EXIT_FAILURE);
 138                 }
 139
 140                 fw->fw[fw->fw_blocks][0] = (fw->fw_blocks >> 8) & 0xff;
 141                 fw->fw[fw->fw_blocks][1] = fw->fw_blocks & 0xff;
 142                 fw->fw[fw->fw_blocks][2] = (len >> 8) & 0xff;
 143                 fw->fw[fw->fw_blocks][3] = len & 0xff;
 144
 145                 r = read(fd, buf, len * 2);
 146                 if (r < 0) {
 147                         perror("read");
 148                         exit(EXIT_FAILURE);
 149                 } else if (r < len * 2) {
 150                         fprintf(stderr, "short read, aborting (%d < %d)\n", r, len * 2);
 151                         exit(EXIT_FAILURE);
 152                 }
 153
 154                 for (i = 0; i < r; i+=2) {
 155                         if ((!validate_nibble(buf[i])) ||
 156                             (!validate_nibble(buf[i+1]))) {
 157                                 fprintf(stderr, "Firmware file not valid!\n");
 158                                 exit(EXIT_FAILURE);
 159                         }
 160
 161                         fw->fw[fw->fw_blocks][(i/2) + 4] = (ascii_to_nibble(buf[i]) & 0xf)<< 4;
 162                         fw->fw[fw->fw_blocks][(i/2) + 4] |= ascii_to_nibble(buf[i+1]) & 0xf;
 163                 }
 164
 165                 fw->fw_blocks++;
 166                 if (debug)
 167                         printf("Firmware block %d with length %u read.\n", fw->fw_blocks, len);
 168         } while(r > 0);
 169
 170         if (fw->fw_blocks == 0) {
 171                 fprintf(stderr, "Firmware file not valid!\n");
 172                 exit(EXIT_FAILURE);
 173         }
 174
 175         printf("Firmware with %d blocks successfully read.\n", fw->fw_blocks);
 176
 177         return fw;
 178 }
 179
 180 void firmware_free(struct firmware *fw)
 181 {
 182         int i;
 183
 184         for (i = 0; i < fw->fw_blocks; i++)
 185                 free(fw->fw[i]);
 186
 187         free(fw->fw);
 188         free(fw);
 189 }