litex/software/bios/tftp.c

120 lines
2.5 KiB
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#include <string.h>
#include "microudp.h"
#include "tftp.h"
#define PORT_OUT 69
#define PORT_IN 7642
static int format_request(char *buf, const char *filename)
{
*buf++ = 0x00; /* Opcode: Request */
*buf++ = 0x01;
strcpy(buf, filename);
buf += strlen(filename);
*buf++ = 0x00;
*buf++ = 'o';
*buf++ = 'c';
*buf++ = 't';
*buf++ = 'e';
*buf++ = 't';
*buf++ = 0x00;
return 9+strlen(filename);
}
static int format_ack(char *buf, unsigned short block)
{
*buf++ = 0x00; /* Opcode: Ack */
*buf++ = 0x04;
*buf++ = (block & 0xff00) >> 8;
*buf++ = (block & 0x00ff);
return 4;
}
static char *packet_data;
static int total_length;
static int transfer_finished;
static char *dst_buffer;
static void rx_callback(unsigned int src_ip, unsigned short src_port, unsigned short dst_port, void *_data, unsigned int length)
{
unsigned char *data = (unsigned char *)_data;
unsigned short opcode;
unsigned short block;
int i;
int offset;
if(length < 4) return;
if(dst_port != PORT_IN) return;
opcode = ((unsigned short)(data[0]) << 8)|((unsigned short)(data[1]));
block = ((unsigned short)(data[2]) << 8)|((unsigned short)(data[3]));
if(block < 1) return;
if(opcode == 3) { /* Data */
length -= 4;
offset = (block-1)*512;
for(i=0;i<length;i++)
dst_buffer[offset+i] = data[i+4];
total_length += length;
if(length < 512)
transfer_finished = 1;
length = format_ack(packet_data, block);
microudp_send(PORT_IN, src_port, length);
}
if(opcode == 5) { /* Error */
total_length = -1;
transfer_finished = 1;
}
}
int tftp_get(unsigned int ip, const char *filename, char *buffer)
{
int len;
int tries;
int i;
int length_before;
if(!microudp_arp_resolve(ip))
return -1;
microudp_set_callback(rx_callback);
packet_data = microudp_get_tx_buffer();
dst_buffer = buffer;
total_length = 0;
transfer_finished = 0;
tries = 5;
while(1) {
len = format_request(packet_data, filename);
microudp_send(PORT_IN, PORT_OUT, len);
for(i=0;i<2000000;i++) {
microudp_service();
if((total_length > 0) || transfer_finished) break;
}
if((total_length > 0) || transfer_finished) break;
tries--;
if(tries == 0) {
microudp_set_callback(NULL);
return -1;
}
}
length_before = total_length;
while(!transfer_finished) {
if(length_before != total_length) {
i = 12000000;
length_before = total_length;
}
if(i-- == 0) {
microudp_set_callback(NULL);
return -1;
}
microudp_service();
}
microudp_set_callback(NULL);
return total_length;
}