picoproj.c

   1 /* picoproj - communication with AM7xxx based USB pico projectors
   2  *
   3  * Copyright (C) 2011  Antonio Ospite <ospite@studenti.unina.it>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stdint.h>
  22 #include <string.h>
  23 #include <endian.h>
  24 #include <errno.h>
  25
  26 /*
  27  * Examples of a packet headers:
  28  *
  29  * Image widget:
  30  * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  31  * +02|00|00|00|00|10|3e|10|01|00|00|00|20|03|00|00|e0|01|00|00|53|E8|00|00+
  32  * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  33  *
  34  * Brightness widget:
  35  * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  36  * +04|00|00|00|00|0c|ff|ff|00|00|00|00|00|00|00|00|00|00|00|00|00|00|00|00+
  37  * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  38  */
  39
  40 #define AM7x01_PACKET_TYPE_INIT    0x01
  41 #define AM7x01_PACKET_TYPE_IMAGE   0x02
  42 #define AM7x01_PACKET_TYPE_POWER   0x04
  43 #define AM7x01_PACKET_TYPE_UNKNOWN 0x05
  44
  45 struct buffer {
  46         unsigned int len;
  47         uint8_t *data;
  48 };
  49
  50 struct header{
  51         uint32_t packet_type;
  52         uint32_t unknown1;
  53         uint32_t unknown2;
  54         uint32_t width;
  55         uint32_t height;
  56         uint32_t payload_size;
  57 };
  58
  59 struct packet {
  60         struct header header;
  61         uint8_t payload[];
  62 };
  63
  64 static struct buffer *packet_allocate_buffer(struct packet *p)
  65 {
  66         struct buffer *buffer;
  67
  68         if (p == NULL) {
  69                 perror("packet NULL");
  70                 return NULL;
  71         }
  72
  73         buffer = malloc(sizeof(*buffer));
  74         if (buffer == NULL) {
  75                 perror("malloc buffer");
  76                 return NULL;
  77         }
  78
  79         buffer->len = sizeof(p->header); /* + p->header.payload_size; */
  80
  81         buffer->data = malloc(buffer->len);
  82         if (buffer->data == NULL) {
  83                 perror("malloc buffer->data");
  84                 free(buffer);
  85                 return NULL;
  86         }
  87         return buffer;
  88 }
  89
  90 static void packet_free_buffer(struct buffer *buffer)
  91 {
  92         free(buffer->data);
  93         free(buffer);
  94         buffer = NULL;
  95 }
  96
  97 static int packet_pack(struct packet *p, struct buffer *buffer)
  98 {
  99         unsigned int offset;
 100         uint32_t tmp;
 101
 102         if (p == NULL || buffer == NULL)
 103                 return -EINVAL;
 104
 105         /* TODO: check for packet payload being NULL? */
 106         if (buffer->data == NULL || buffer->len < sizeof(*p))
 107                 return -EINVAL;
 108
 109         offset = 0;
 110
 111         tmp = htole32(p->header.packet_type);
 112         memcpy(buffer->data + offset, &tmp, sizeof(p->header.packet_type));
 113         offset += sizeof(p->header.packet_type);
 114
 115         tmp = htole32(p->header.unknown1);
 116         memcpy(buffer->data + offset, &tmp, sizeof(p->header.unknown1));
 117         offset += sizeof(p->header.unknown1);
 118
 119         tmp = htole32(p->header.unknown2);
 120         memcpy(buffer->data + offset, &tmp, sizeof(p->header.unknown2));
 121         offset += sizeof(p->header.unknown2);
 122
 123         tmp = htole32(p->header.width);
 124         memcpy(buffer->data + offset, &tmp, sizeof(p->header.width));
 125         offset += sizeof(p->header.width);
 126
 127         tmp = htole32(p->header.height);
 128         memcpy(buffer->data + offset, &tmp, sizeof(p->header.height));
 129         offset += sizeof(p->header.height);
 130
 131         tmp = htole32(p->header.payload_size);
 132         memcpy(buffer->data + offset, &tmp, sizeof(p->header.payload_size));
 133         offset += sizeof(p->header.payload_size);
 134
 135         /* TODO memcpy payload of size */
 136
 137         return 0;
 138 }
 139
 140 static int packet_unpack(struct buffer *buffer, struct packet *p)
 141 {
 142         unsigned int offset;
 143         uint32_t tmp;
 144
 145         if (p == NULL || buffer == NULL)
 146                 return -EINVAL;
 147
 148         /* TODO: check for packet payload being NULL? */
 149         if (buffer->data == NULL || buffer->len < sizeof(*p))
 150                 return -EINVAL;
 151
 152         offset = 0;
 153
 154         memcpy(&tmp, buffer->data + offset, sizeof(p->header.packet_type));
 155         p->header.packet_type = le32toh(tmp);
 156         offset += sizeof(p->header.packet_type);
 157
 158         memcpy(&tmp, buffer->data + offset, sizeof(p->header.unknown1));
 159         p->header.unknown1 = le32toh(tmp);
 160         offset += sizeof(p->header.unknown1);
 161
 162         memcpy(&tmp, buffer->data + offset, sizeof(p->header.unknown2));
 163         p->header.unknown2 = le32toh(tmp);
 164         offset += sizeof(p->header.unknown2);
 165
 166         memcpy(&tmp, buffer->data + offset, sizeof(p->header.width));
 167         p->header.width = le32toh(tmp);
 168         offset += sizeof(p->header.width);
 169
 170         memcpy(&tmp, buffer->data + offset, sizeof(p->header.height));
 171         p->header.height = le32toh(tmp);
 172         offset += sizeof(p->header.height);
 173
 174         memcpy(&tmp, buffer->data + offset, sizeof(p->header.payload_size));
 175         p->header.payload_size = le32toh(tmp);
 176         offset += sizeof(p->header.payload_size);
 177
 178         /* malloc & memcpy payload of size p->header.payload_size */
 179
 180         return 0;
 181 }
 182
 183 static void packet_dump_header(struct packet *p)
 184 {
 185         if (p == NULL)
 186                 return;
 187
 188         printf("packet_type: 0x%08x (%u)\n", p->header.packet_type, p->header.packet_type);
 189         printf("unknown1:    0x%08x (%u)\n", p->header.unknown1, p->header.unknown1);
 190         printf("unknown2:    0x%08x (%u)\n", p->header.unknown2, p->header.unknown2);
 191         printf("width:       0x%08x (%u)\n", p->header.width, p->header.width);
 192         printf("height:      0x%08x (%u)\n", p->header.height, p->header.height);
 193         printf("size:        0x%08x (%u)\n", p->header.payload_size, p->header.payload_size);
 194         fflush(stdout);
 195 }
 196
 197 static void packet_dump_buffer(struct buffer *buffer)
 198 {
 199         unsigned int i;
 200
 201         if (buffer == NULL)
 202                 return;
 203
 204         if (buffer->data == NULL)
 205                 return;
 206
 207         for (i = 0; i < buffer->len; i++) {
 208                 printf("%02hhX%c", buffer->data[i], (i < buffer->len - 1) ? ' ' : '\n');
 209         }
 210         fflush(stdout);
 211 }
 212
 213 int main(void)
 214 {
 215         struct packet p1  = {
 216                 .header = {
 217                         .packet_type  = AM7x01_PACKET_TYPE_IMAGE,
 218                         .unknown1     = le32toh(0x103e1000),
 219                         .unknown2     = le32toh(0x00000001),
 220                         .width        = 800,
 221                         .height       = 480,
 222                         .payload_size = 59475,
 223                 },
 224                 /* TODO initialize payload */
 225         };
 226         struct buffer *buffer = NULL;
 227         struct packet p2;
 228         int ret;
 229
 230         packet_dump_header(&p1);
 231
 232         buffer = packet_allocate_buffer(&p1);
 233         if (buffer == NULL) {
 234                 fprintf(stderr, "Cannot allocate the buffer.\n");
 235                 exit(EXIT_FAILURE);
 236         }
 237
 238         ret = packet_pack(&p1, buffer);
 239         if (ret < 0) {
 240                 fprintf(stderr, "Cannot pack the packet.\n");
 241                 exit(EXIT_FAILURE);
 242         }
 243
 244         packet_dump_buffer(buffer);
 245
 246         ret = packet_unpack(buffer, &p2);
 247         if (ret < 0) {
 248                 fprintf(stderr, "Cannot unpack the packet.\n");
 249                 exit(EXIT_FAILURE);
 250         }
 251
 252         packet_dump_header(&p2);
 253
 254         packet_free_buffer(buffer);
 255
 256         exit(EXIT_SUCCESS);
 257 }