[RFC PATCH] commands: change Y-Modem implementation
Robert Jarzmik
robert.jarzmik at free.fr
Fri Oct 26 15:00:11 EDT 2012
The current Y-Modem implementation has some limitations:
- Y-Modem/G protocol is not supported
- Multiple files (aka. batch) transfers are not supported
- Transfer speed over fast lines (USB console) is slow
- Code is not trivial to maintain (personnal opinion)
This implementation tries to address all these points by
introducing loady2 command.
The effects are :
- transfer speed for Y-Modem over USB jumps from 2kBytes/s
to 180kBytes/s
- transfer speed for Y-Modem/G jumps to 200kBytes/s
- multiple file transfers are possible
This command was tested on a USB console. Before going any
further, I'd like barebox communauty opinion about :
- is this code more maintainable that xyzModem.c ?
- is some xyzModem.c functionality missing ?
- can anybody test it on a slow UART line (even better if
it is noisy) to check protocol corner cases ?
Signed-off-by: Robert Jarzmik <robert.jarzmik at free.fr>
---
commands/Kconfig | 5 +
commands/Makefile | 1 +
commands/xymodem.c | 556 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 562 insertions(+)
create mode 100644 commands/xymodem.c
diff --git a/commands/Kconfig b/commands/Kconfig
index 546e58e..adf7328 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -264,6 +264,11 @@ config CMD_LOADY
tristate
prompt "loady"
+config CMD_LOADY2
+ select CRC16
+ tristate
+ prompt "loady2"
+
config CMD_LOADS
tristate
prompt "loads"
diff --git a/commands/Makefile b/commands/Makefile
index ff98051..5576d8b 100644
--- a/commands/Makefile
+++ b/commands/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_CMD_UIMAGE) += uimage.o
obj-$(CONFIG_CMD_LINUX16) += linux16.o
obj-$(CONFIG_CMD_LOADB) += loadb.o xyzModem.o
obj-$(CONFIG_CMD_LOADY) += loadb.o xyzModem.o
+obj-$(CONFIG_CMD_LOADY2) += xymodem.o
obj-$(CONFIG_CMD_LOADS) += loads.o
obj-$(CONFIG_CMD_ECHO) += echo.o
obj-$(CONFIG_CMD_MEMORY) += mem.o
diff --git a/commands/xymodem.c b/commands/xymodem.c
new file mode 100644
index 0000000..2e0822c
--- /dev/null
+++ b/commands/xymodem.c
@@ -0,0 +1,556 @@
+#include <common.h>
+#include <xfuncs.h>
+#include <errno.h>
+#include <crc.h>
+#include <clock.h>
+#include <console.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <command.h>
+#include <fs.h>
+#include <poller.h>
+#include <linux/byteorder/generic.h>
+
+#include <kfifo.h>
+
+#define proto_dbg(fmt, args...)
+
+/* Values magic to the protocol */
+#define SOH 0x01
+#define STX 0x02
+#define EOT 0x04
+#define ACK 0x06
+#define BSP 0x08
+#define NAK 0x15
+#define CAN 0x18
+
+#define PROTO_XMODEM 0
+#define PROTO_YMODEM 1
+#define PROTO_YMODEM_G 2
+#define MAX_PROTOS 3
+
+#define CRC_NONE 0 /* No CRC checking */
+#define CRC_ADD8 1 /* Add of all data bytes */
+#define CRC_CRC16 2 /* CCCIT CRC16 */
+#define MAX_CRCS 3
+
+#define MAX_RETRIES 10
+#define MAX_RETRIES_WITH_CRC 5
+#define TIMEOUT_READ (1 * SECOND)
+#define MAX_CAN_BEFORE_ABORT 5
+
+enum proto_state {
+ PROTO_STATE_GET_FILENAME = 0,
+ PROTO_STATE_NEGOCIATE_CRC,
+ PROTO_STATE_RECEIVE_BODY,
+ PROTO_STATE_FINISHED_FILE,
+ PROTO_STATE_FINISHED_XFER,
+};
+
+/**
+ * struct xyz_ctxt - context of a x/y modem (g) transfer
+ *
+ * @cdev: console device to support *MODEM transfer
+ * @mode: protocol (XMODEM, YMODEM or YMODEM/G)
+ * @crc_mode: CRC_NONE, CRC_ADD8 or CRC_CRC16
+ * @state: protocol state (as in "state machine")
+ * @buf: buffer to store the last tranfered buffer chunk
+ * @filename : filename transmitted by sender (YMODEM* only)
+ * @fd : file descriptor of the current stored file
+ * @file_len: length declared by sender (YMODEM* only)
+ * @nb_received: number of data bytes received since session open
+ * (this doesn't count resends)
+ * @total_SOH: number of SOH frames received (128 bytes chunks)
+ * @total_STX: number of STX frames received (1024 bytes chunks)
+ * @total_CAN: nubmer of CAN frames received (cancel frames)
+ */
+struct xyz_ctxt {
+ struct console_device *cdev;
+ int mode;
+ int crc_mode;
+ enum proto_state state;
+ char filename[1024];
+ int fd;
+ int file_len;
+ int nb_received;
+ int next_blk;
+ int total_SOH, total_STX, total_CAN, total_retries;
+};
+
+/**
+ * struct proto_block - one unitary block of x/y modem (g) transfer
+ *
+ * @buf: data buffer
+ * @len: length of data buffer (can only be 128 or 1024)
+ * @seq: block sequence number (as in X/Y/YG MODEM protocol)
+ */
+struct proto_block {
+ unsigned char buf[1024];
+ int len;
+ int seq;
+};
+
+/*
+ * For XMODEM/YMODEM, always try to use the CRC16 versions, called also
+ * XMODEM/CRC and YMODEM.
+ * Only fallback to additive CRC (8 bits) if sender doesn't cope with CRC16.
+ */
+static const char invite_filename_hdr[MAX_PROTOS][MAX_CRCS] = {
+ { 0, NAK, 'C' }, /* XMODEM */
+ { 0, NAK, 'C' }, /* YMODEM */
+ { 0, 'G', 'G' }, /* YMODEM-G */
+};
+
+static const char invite_file_body[MAX_PROTOS][MAX_CRCS] = {
+ { 0, NAK, 'C' }, /* XMODEM */
+ { 0, NAK, 'C' }, /* YMODEM */
+ { 0, 'G', 'G' }, /* YMODEM-G */
+};
+
+static const char block_ack[MAX_PROTOS][MAX_CRCS] = {
+ { 0, ACK, ACK }, /* XMODEM */
+ { 0, ACK, ACK }, /* YMODEM */
+ { 0, 0, 0 }, /* YMODEM-G */
+};
+
+static const char block_nack[MAX_PROTOS][MAX_CRCS] = {
+ { 0, NAK, NAK }, /* XMODEM */
+ { 0, NAK, NAK }, /* YMODEM */
+ { 0, 0, 0 }, /* YMODEM-G */
+};
+
+static int proto_gets(struct console_device *cdev, unsigned char *buf, int len,
+ uint64_t timeout)
+{
+ int i, rc;
+ uint64_t start = get_time_ns();
+
+ for (i = 0, rc = 0; rc >= 0 && i < len; ) {
+ if (is_timeout(start, timeout)) {
+ rc = -ETIMEDOUT;
+ continue;
+ }
+ if (cdev->tstc(cdev))
+ buf[i++] = (unsigned char)(cdev->getc(cdev));
+ }
+
+ return rc < 0 ? rc : i;
+}
+
+static void proto_putc(struct console_device *cdev, unsigned char c)
+{
+ cdev->putc(cdev, c);
+}
+
+static void proto_flush(struct console_device *cdev)
+{
+ while (cdev->tstc(cdev))
+ cdev->getc(cdev);
+}
+
+static int is_xmodem(struct xyz_ctxt *proto)
+{
+ return proto->mode == PROTO_XMODEM;
+}
+
+static void proto_block_ack(struct xyz_ctxt *proto)
+{
+ unsigned char c = block_ack[proto->mode][proto->crc_mode];
+
+ if (c)
+ proto_putc(proto->cdev, c);
+}
+
+static void proto_block_nack(struct xyz_ctxt *proto)
+{
+ unsigned char c = block_nack[proto->mode][proto->crc_mode];
+
+ if (c)
+ proto_putc(proto->cdev, c);
+}
+
+static int check_crc(unsigned char *buf, int len, int crc, int crc_mode)
+{
+ unsigned char crc8 = 0;
+ uint16_t crc16;
+ int i;
+
+ switch (crc_mode) {
+ case CRC_ADD8:
+ for (i = 0; i < len; i++)
+ crc8 += buf[i];
+ return crc8 == crc ? 0 : -EBADMSG;
+ case CRC_CRC16:
+ crc16 = cyg_crc16(buf, len);
+ proto_dbg("crc16: received = %x, calculated=%x\n", crc, crc16);
+ return crc16 == crc ? 0 : -EBADMSG;
+ case CRC_NONE:
+ return 0;
+ default:
+ return -EBADMSG;
+ }
+}
+
+static ssize_t proto_read_block(struct xyz_ctxt *proto, struct proto_block *blk,
+ uint64_t timeout)
+{
+ ssize_t rc, data_len = 0;
+ unsigned char hdr, seqs[2];
+ int crc = 0, hdr_found = 0;
+ uint64_t start = get_time_ns();
+
+ while (!hdr_found) {
+ rc = proto_gets(proto->cdev, &hdr, 1, timeout);
+ proto_dbg("read 0x%x(%c) -> %d\n", hdr, hdr, rc);
+ if (rc < 0)
+ goto out;
+ if (is_timeout(start, timeout))
+ goto timeout;
+ switch (hdr) {
+ case SOH:
+ data_len = 128;
+ hdr_found = 1;
+ proto->total_SOH++;
+ break;
+ case STX:
+ data_len = 1024;
+ hdr_found = 1;
+ proto->total_STX++;
+ break;
+ case CAN:
+ rc = -ECONNABORTED;
+ if (proto->total_CAN++ > MAX_CAN_BEFORE_ABORT)
+ goto out;
+ break;
+ case EOT:
+ rc = 0;
+ blk->len = 0;
+ goto out;
+ default:
+ break;
+ }
+ }
+
+ blk->seq = 0;
+ rc = proto_gets(proto->cdev, seqs, 2, timeout);
+ if (rc < 0)
+ goto out;
+ blk->seq = seqs[0];
+ if (255 - seqs[0] != seqs[1])
+ return -EBADMSG;
+
+ rc = proto_gets(proto->cdev, blk->buf, data_len, timeout);
+ if (rc < 0)
+ goto out;
+ blk->len = rc;
+
+ switch (proto->crc_mode) {
+ case CRC_ADD8:
+ rc = proto_gets(proto->cdev,
+ (unsigned char *)&crc, 1, timeout);
+ break;
+ case CRC_CRC16:
+ rc = proto_gets(proto->cdev,
+ (unsigned char *)&crc, 2, timeout);
+ crc = be16_to_cpu(crc);
+ break;
+ case CRC_NONE:
+ rc = 0;
+ break;
+ }
+ if (rc < 0)
+ goto out;
+
+ rc = check_crc(blk->buf, data_len, crc, proto->crc_mode);
+ if (rc < 0)
+ goto out;
+ return data_len;
+timeout:
+ return -ETIMEDOUT;
+out:
+ return rc;
+}
+
+static int check_blk_seq(struct xyz_ctxt *proto, struct proto_block *blk,
+ int read_rc)
+{
+ if (blk->seq == ((proto->next_blk - 1) % 256))
+ return -EALREADY;
+ if (blk->seq != proto->next_blk)
+ return -EILSEQ;
+ return read_rc;
+}
+
+static int parse_first_block(struct xyz_ctxt *proto, struct proto_block *blk)
+{
+ int filename_len;
+ char *str_num;
+
+ filename_len = strlen(blk->buf);
+ if (filename_len > blk->len)
+ return -EINVAL;
+ memset(proto->filename, 0, sizeof(proto->filename));
+ strncpy(proto->filename, blk->buf, filename_len);
+ str_num = blk->buf + filename_len + 1;
+ strsep(&str_num, " ");
+ proto->file_len = simple_strtoul(blk->buf + filename_len + 1, NULL, 10);
+ return 1;
+}
+
+static int proto_get_file_header(struct xyz_ctxt *proto)
+{
+ struct proto_block blk;
+ int tries, rc = 0;
+
+ memset(&blk, 0, sizeof(blk));
+ proto->state = PROTO_STATE_GET_FILENAME;
+ proto->crc_mode = CRC_CRC16;
+ for (tries = 0; tries < MAX_RETRIES; tries++) {
+ proto_putc(proto->cdev,
+ invite_filename_hdr[proto->mode][proto->crc_mode]);
+ rc = proto_read_block(proto, &blk, 3 * SECOND);
+ proto_dbg("read block returned %d\n", rc);
+ switch (rc) {
+ case -ECONNABORTED:
+ goto fail;
+ case -ETIMEDOUT:
+ if (proto->mode != PROTO_YMODEM_G)
+ mdelay(1000);
+ break;
+ case -EBADMSG:
+ /* The NACK/C/G char will be sent by invite_file_body */
+ break;
+ case -EALREADY:
+ default:
+ proto->next_blk = 1;
+ proto_block_ack(proto);
+ proto->crc_mode = CRC_CRC16;
+ proto->state = PROTO_STATE_NEGOCIATE_CRC;
+ rc = parse_first_block(proto, &blk);
+ return rc;
+ }
+
+ if (rc < 0 && tries++ >= MAX_RETRIES_WITH_CRC)
+ proto->crc_mode = CRC_ADD8;
+ }
+ rc = -ETIMEDOUT;
+fail:
+ return rc;
+}
+
+static int proto_await_header(struct xyz_ctxt *proto)
+{
+ int rc;
+
+ rc = proto_get_file_header(proto);
+ if (rc < 0)
+ return rc;
+ if (is_xmodem(proto))
+ proto->state = PROTO_STATE_RECEIVE_BODY;
+ else
+ proto->state = PROTO_STATE_NEGOCIATE_CRC;
+ proto_dbg("header received, filename=%s, file length=%d\n",
+ proto->filename, proto->file_len);
+ if (proto->filename[0])
+ proto->fd = open(proto->filename, O_WRONLY | O_CREAT);
+ else
+ proto->state = PROTO_STATE_FINISHED_XFER;
+
+ return rc;
+}
+
+static void proto_finish_file(struct xyz_ctxt *proto)
+{
+ close(proto->fd);
+ proto->fd = 0;
+ proto->state = PROTO_STATE_FINISHED_FILE;
+}
+
+static struct xyz_ctxt *proto_open(struct console_device *cdev,
+ int proto_mode, char *xmodem_filename)
+{
+ struct xyz_ctxt *proto;
+
+ proto = xzalloc(sizeof(struct xyz_ctxt));
+ proto->mode = proto_mode;
+ proto->cdev = cdev;
+
+ if (is_xmodem(proto)) {
+ proto->fd = open(xmodem_filename, O_WRONLY | O_CREAT);
+ proto->state = PROTO_STATE_RECEIVE_BODY;
+ } else {
+ proto->state = PROTO_STATE_GET_FILENAME;
+ }
+ proto_flush(proto->cdev);
+ return proto;
+}
+
+static int proto_handle(struct xyz_ctxt *proto)
+{
+ int rc = 0, xfer_max, len = 0, again = 1;
+ struct proto_block blk;
+
+ while (again) {
+ switch (proto->state) {
+ case PROTO_STATE_GET_FILENAME:
+ rc = proto_await_header(proto);
+ if (rc < 0)
+ goto fail;
+ continue;
+ case PROTO_STATE_FINISHED_FILE:
+ rc = proto_read_block(proto, &blk, 3 * SECOND);
+ if (rc < 0)
+ goto fail;
+ if (rc > 0)
+ continue;
+ if (is_xmodem(proto))
+ proto->state = PROTO_STATE_FINISHED_XFER;
+ else
+ proto->state = PROTO_STATE_GET_FILENAME;
+ proto_putc(proto->cdev, ACK);
+ continue;
+ case PROTO_STATE_FINISHED_XFER:
+ again = 0;
+ rc = 0;
+ goto out;
+ case PROTO_STATE_NEGOCIATE_CRC:
+ proto_putc(proto->cdev,
+ invite_file_body[proto->mode][proto->crc_mode]);
+ /* Fall through */
+ case PROTO_STATE_RECEIVE_BODY:
+ rc = proto_read_block(proto, &blk, 3 * SECOND);
+ if (rc > 0) {
+ rc = check_blk_seq(proto, &blk, rc);
+ proto->state = PROTO_STATE_RECEIVE_BODY;
+ }
+ break;
+ }
+
+ switch (rc) {
+ case -ECONNABORTED:
+ goto fail;
+ case -ETIMEDOUT:
+ if (proto->mode == PROTO_YMODEM_G)
+ goto fail;
+ continue;
+ case -EBADMSG:
+ case -EILSEQ:
+ if (proto->mode == PROTO_YMODEM_G)
+ goto fail;
+ proto->total_retries++;
+ proto_block_nack(proto);
+ break;
+ case -EALREADY:
+ proto_block_ack(proto);
+ break;
+ case 0:
+ proto_finish_file(proto);
+ break;
+ default:
+ if (is_xmodem(proto))
+ xfer_max = blk.len;
+ else
+ xfer_max = min(blk.len,
+ proto->file_len - proto->nb_received);
+ rc = write(proto->fd, blk.buf, xfer_max);
+ proto->next_blk = ((blk.seq + 1) % 256);
+ proto->nb_received += rc;
+ len += rc;
+ proto_block_ack(proto);
+ if (xfer_max < blk.len || blk.len == 0)
+ proto_finish_file(proto);
+ continue;
+ }
+ }
+out:
+ return rc;
+fail:
+ if (proto->fd)
+ close(proto->fd);
+ return rc;
+}
+
+/**
+ * @brief returns current used console device
+ *
+ * @return console device which is registered with CONSOLE_STDIN and
+ * CONSOLE_STDOUT
+ */
+static struct console_device *get_current_console(void)
+{
+ struct console_device *cdev;
+ /*
+ * Assumption to have BOTH CONSOLE_STDIN AND STDOUT in the
+ * same output console
+ */
+ for_each_console(cdev) {
+ if ((cdev->f_active & (CONSOLE_STDIN | CONSOLE_STDOUT)))
+ return cdev;
+ }
+ return NULL;
+}
+
+static void proto_close(struct xyz_ctxt *proto)
+{
+ printf("xyModem - %d(SOH)/%d(STX)/%d(CAN) packets,"
+ " %d retries\n",
+ proto->total_SOH, proto->total_STX,
+ proto->total_CAN, proto->total_retries);
+}
+
+/**
+ * @brief provide the loady2(ymodem)
+ *
+ * @param cmdtp
+ * @param argc
+ * @param argv
+ *
+ * @return success or failure
+ */
+static int do_load_serial_bin(int argc, char *argv[])
+{
+ int use_ymodem_g = 0, load_baudrate = -1, rc, opt;
+ struct console_device *cdev;
+ struct xyz_ctxt *proto;
+ ssize_t size = 0;
+
+ while ((opt = getopt(argc, argv, "b:g")) > 0) {
+ switch (opt) {
+ case 'b':
+ load_baudrate = (int)simple_strtoul(optarg, NULL, 10);
+ break;
+ case 'g':
+ use_ymodem_g = 1;
+ break;
+ default:
+ perror(argv[0]);
+ return 1;
+ }
+ }
+
+ cdev = get_current_console();
+ proto_flush(cdev);
+ proto = proto_open(cdev, use_ymodem_g ? PROTO_YMODEM_G : PROTO_YMODEM,
+ "");
+ while ((rc = proto_handle(proto)) > 0)
+ size += rc;
+ proto_close(proto);
+ proto_flush(cdev);
+ return rc < 0 ? rc : COMMAND_SUCCESS;
+}
+
+#ifdef CONFIG_CMD_LOADY2
+static const __maybe_unused char cmd_loady2_help[] =
+ "[OPTIONS]\n"
+ " -b baud - baudrate at which to download - defaults to "
+ "console baudrate\n"
+ " -g - use ymodem-g instead of ymodem";
+
+BAREBOX_CMD_START(loady2)
+ .cmd = do_load_serial_bin,
+ .usage = "Load binary file over serial line (ymodem mode)",
+ BAREBOX_CMD_HELP(cmd_loady2_help)
+BAREBOX_CMD_END
+#endif
--
1.7.10
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