Add XMODEM support compatible w/ HDMI2USB

flterm.c

@@ -36,6 +36,7 @@
 #include <unistd.h>
 
 #include <sfl.h>
+#include <xmodem.h>
 
 #ifdef __linux__
 #include <linux/serial.h>
@@ -107,6 +108,31 @@ static unsigned short crc16(const void *_buffer, int len)
 	return crc;
 }
 
+unsigned short xmodem_crc16(unsigned char * data, size_t size)
+{
+	const unsigned int crc_poly = 0x1021;
+	unsigned int crc = 0x0000;
+
+	unsigned int octet_count;
+	unsigned char bit_count;
+	for(octet_count = 0; octet_count < size; octet_count++)
+	{
+		crc = (crc ^ (unsigned int) (data[octet_count] & (0xFF)) << 8);
+		for(bit_count = 1; bit_count <= 8; bit_count++)
+		{
+			if(crc & 0x8000)
+			{
+				crc = (crc << 1) ^ crc_poly;
+			}
+			else
+			{
+				crc <<= 1;
+			}
+		}
+	}
+	return crc;
+}
+
 static int write_exact(int fd, const char *data, unsigned int length)
 {
 	int r;
@@ -206,6 +232,103 @@ static int upload_fd(int serialfd, const char *name, int firmwarefd, unsigned in
 	return length;
 }
 
+static int upload_xmodem(int serialfd, const char *name, int firmwarefd)
+{
+	struct xmodem_packet packet;
+	unsigned char curr_packet = 1;
+	int less_than_1k = 0;
+	int firmware_pos = 0;
+	int err_count = 0;
+	int done = 0;
+	int length;
+	struct timeval t0;
+	struct timeval t1;
+	int millisecs;
+
+
+	length = lseek(firmwarefd, 0, SEEK_END);
+	lseek(firmwarefd, 0, SEEK_SET);
+
+	printf("[FLTERM] Uploading %s (%d bytes)...\n", name, length);
+
+	gettimeofday(&t0, NULL);
+
+	// Abbreviated XMODEM transmitter- only sends 1024 byte packets. Expects
+	// receiver to
+	while(!done) {
+		char reply;
+		int readbytes;
+		unsigned short crc;
+
+		printf("%d%%\r", 100*firmware_pos/length);
+		fflush(stdout);
+
+		packet.start = less_than_1k ? SOH : STX;
+		packet.num = curr_packet;
+		packet.num_comp = ~packet.num;
+
+		readbytes = read(firmwarefd, &packet.payload, 1024);
+		if(readbytes < 0) {
+			perror("[FLTERM] Unable to read image.");
+			return -1;
+		}
+
+		// Pad final packet per XMODEM spec.
+		if(readbytes < sizeof(packet.payload)) {
+			done = 1;
+			memset(&packet.payload[0] + readbytes, CPMEOF, 1024 - readbytes);
+		}
+
+		crc = xmodem_crc16(packet.payload, 1024);
+		packet.crc[0] = (crc & 0xff00) >> 8;
+		packet.crc[1] = (crc & 0x00ff);
+
+		if(!write_exact(serialfd, (char *) &packet, 1029)) {
+			perror("[FLTERM] Unable to write to serial port.");
+			return 0;
+		}
+
+		read(serialfd, &reply, 1);
+
+		if(reply == ACK) {
+			if(!done) {
+				curr_packet++;
+				firmware_pos += 1024;
+				err_count = 0;
+			}
+		} else {
+			if(err_count < 11) {
+				lseek(firmwarefd, firmware_pos, SEEK_SET);
+				done = 0; // Last packet may need to be resent.
+				err_count++;
+			} else {
+				perror("[FLTERM] Error count exceeded while transmitting. Aborting.");
+				return 0;
+			}
+		}
+	}
+
+	{
+		const char eot = EOT;
+		char last_reply;
+		write_exact(serialfd, &eot, 1);
+		read(serialfd, &last_reply, 1);
+
+		if(last_reply != ACK) {
+			perror("[FLTERM] Sent EOT, but did not receive ACK. Aborting.");
+			return 0;
+		}
+	}
+
+
+	gettimeofday(&t1, NULL);
+	millisecs = (t1.tv_sec - t0.tv_sec)*1000 + (t1.tv_usec - t0.tv_usec)/1000;
+
+	printf("[FLTERM] Upload complete (%.1fKB/s).\n", 1000.0*(double)length/((double)millisecs*1024.0));
+	return length;
+}
+
+
 static const char sfl_magic_req[SFL_MAGIC_LEN] = SFL_MAGIC_REQ;
 static const char sfl_magic_ack[SFL_MAGIC_LEN] = SFL_MAGIC_ACK;
 
@@ -307,6 +430,26 @@ static void answer_magic(int serialfd,
 	close(kernelfd);
 }
 
+static void answer_xmodem(int serialfd, const char *kernel_image) {
+	int kernelfd;
+
+	printf("[FLTERM] Received XMODEM start char ('C') and kernel image specified.\n");
+
+	kernelfd = open(kernel_image, O_RDONLY);
+	if(kernelfd == -1) {
+		perror("[FLTERM] Unable to open kernel image (request ignored).");
+		return;
+	}
+
+	upload_xmodem(serialfd, "kernel", kernelfd);
+
+	printf("[FLTERM] Done. To do another XMODEM xfer, respawn flterm.\n");
+
+	close(kernelfd);
+}
+
+
+
 static int hex(unsigned char c)
 {
 	if(c >= 'a' && c <= 'f') {
@@ -433,6 +576,8 @@ static void do_terminal(
 	const char *initrd_image, unsigned int initrd_address,
 	char *log_path)
 {
+	int first_xstart = 1; /* XMODEM should only run once, and only if kernel
+	was supplied. */
 	int serialfd;
 	int gdbfd = -1;
 	FILE *logfd = NULL;
@@ -610,8 +755,16 @@ static void do_terminal(
 								cmdline, cmdline_address,
 								initrd_image, initrd_address);
 						}
-					} else {
+					} else if(c != 'C') {
+						/* If XMODEM start not detected, continue looking
+						for SFL start. */
 						if(c == sfl_magic_req[0]) recognized = 1; else recognized = 0;
+					} else {
+						/* XMODEM detected */
+						if(first_xstart) {
+							answer_xmodem(serialfd, kernel_image);
+							first_xstart = 0;
+						}
 					}
 				}
 			}

xmodem.h

@@ -0,0 +1,20 @@
+#ifndef __XMODEM_H
+#define __XMODEM_H
+
+
+struct xmodem_packet {
+	unsigned char start;
+	unsigned char num;
+	unsigned char num_comp;
+	unsigned char payload[1024];
+	unsigned char crc[2];
+} __attribute__((packed));
+
+#define SOH 0x01
+#define STX 0x02
+#define EOT 0x04
+#define ACK 0x06
+#define NAK 0x15
+#define CPMEOF 0x1A
+
+#endif