1 /*
2 * Ymodem send routine. Only supports 1K blocks and CRC mode.
3 */
4
5 #include <string.h>
6 #include <stdio.h>
7 #include <inttypes.h>
8 #include "upload_backend.h"
9 #include "serial.h"
10
11 enum {
12 SOH = 0x01,
13 STX = 0x02,
14 EOT = 0x04,
15 ACK = 0x06,
16 NAK = 0x15,
17 CAN = 0x18,
18 };
19
20 struct ymodem_state {
21 struct serial_if serial;
22 unsigned int seq, blocks;
23 };
24
25 /*
26 * Append a CRC16 to a block
27 */
add_crc16(uint8_t * blk,int len)28 static void add_crc16(uint8_t * blk, int len)
29 {
30 static const uint16_t crctab[256] = {
31 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
32 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
33 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
34 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
35 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
36 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
37 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
38 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
39 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
40 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
41 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
42 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
43 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
44 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
45 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
46 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
47 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
48 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
49 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
50 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
51 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
52 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
53 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
54 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
55 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
56 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
57 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
58 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
59 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
60 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
61 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
62 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
63 };
64 uint16_t crc = 0;
65
66 while (len--)
67 crc = crctab[(crc >> 8) ^ *blk++] ^ crc << 8;
68
69 *blk++ = crc >> 8;
70 *blk = crc;
71 }
72
73 static void send_ack(struct ymodem_state *ym, const uint8_t *blk,
74 size_t bytes);
75
send_ack_blk(struct ymodem_state * ym,uint8_t * blk)76 static void send_ack_blk(struct ymodem_state *ym, uint8_t *blk)
77 {
78 printf("Sending block %u/%u...\r", ym->seq, ym->blocks);
79
80 blk[0] = STX;
81 blk[1] = ym->seq++;
82 blk[2] = ~blk[1];
83 add_crc16(blk+3, 1024);
84
85 send_ack(ym, blk, 1024+5);
86 }
87
send_ack(struct ymodem_state * ym,const uint8_t * blk,size_t bytes)88 static void send_ack(struct ymodem_state *ym, const uint8_t *blk, size_t bytes)
89 {
90 uint8_t ack_buf;
91
92 do {
93 serial_write(&ym->serial, blk, bytes);
94
95 do {
96 serial_read(&ym->serial, &ack_buf, 1);
97 } while (ack_buf != ACK && ack_buf != NAK);
98 } while (ack_buf == NAK);
99 }
100
upload_ymodem_write(struct upload_backend * be)101 static int upload_ymodem_write(struct upload_backend *be)
102 {
103 static const uint8_t eot_buf = EOT;
104 uint8_t ack_buf;
105 uint8_t blk_buf[1024 + 5];
106 struct ymodem_state ym;
107 const char *buf;
108 size_t len, chunk;
109 const char ymodem_banner[] = "Now begin Ymodem download...\r\n";
110
111 buf = be->outbuf;
112 len = be->zbytes;
113
114 putchar('\n');
115
116 ym.seq = 0;
117 ym.blocks = (len+1023)/1024;
118
119 /* Initialize serial port */
120 if (serial_init(&ym.serial, &be->argv[1]))
121 return -1;
122
123 /* Write banner */
124 printf("Writing banner...\n");
125 serial_write(&ym.serial, ymodem_banner, sizeof ymodem_banner-1);
126
127 /* Wait for initial handshake */
128 printf("Waiting for handshake...\n");
129 do {
130 serial_read(&ym.serial, &ack_buf, 1);
131 } while (ack_buf != 'C');
132
133 /* Send filename block */
134 memset(blk_buf, 0, sizeof blk_buf);
135 snprintf((char *)blk_buf+3, 1024, "%s%c%zu 0%o 0644",
136 be->argv[0], 0, be->zbytes, be->now);
137 send_ack_blk(&ym, blk_buf);
138
139 while (len) {
140 chunk = len < 1024 ? len : 1024;
141
142 memcpy(blk_buf+3, buf, chunk);
143 if (chunk < 1024)
144 memset(blk_buf+3+chunk, 0x1a, 1024-chunk);
145
146 send_ack_blk(&ym, blk_buf);
147 buf += chunk;
148 len -= chunk;
149 }
150
151 printf("\nSending EOT...\n");
152 send_ack(&ym, &eot_buf, 1);
153
154 printf("Waiting for handshake...\n");
155 do {
156 serial_read(&ym.serial, &ack_buf, 1);
157 } while (ack_buf != 'C');
158 ym.seq = 0;
159
160 printf("Sending batch termination block...\n");
161 memset(blk_buf+3, 0, 1024);
162 send_ack_blk(&ym, blk_buf);
163
164 printf("Cleaning up... \n");
165 serial_cleanup(&ym.serial);
166
167 return 0;
168 }
169
170 struct upload_backend upload_ymodem = {
171 .name = "ymodem",
172 .helpmsg = "filename [port [speed]]",
173 .minargs = 1,
174 .write = upload_ymodem_write,
175 };
176