104 lines
2.8 KiB
C

/*
* This file is part of the Black Magic Debug project.
*
* Copyright (C) 2011 Black Sphere Technologies Ltd.
* Written by Gareth McMullin <gareth@blacksphere.co.nz>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* This file implements a transparent channel over which the GDB Remote
* Serial Debugging protocol is implemented. This implementation for STM32
* uses the USB CDC-ACM device bulk endpoints to implement the channel.
*/
#include "general.h"
#include "gdb_if.h"
#include "cdcacm.h"
#include <libopencm3/usb/usbd.h>
static volatile uint32_t head_out, tail_out;
static volatile uint32_t count_in;
static volatile uint8_t buffer_out[16*CDCACM_PACKET_SIZE];
static volatile uint8_t buffer_in[CDCACM_PACKET_SIZE];
void gdb_if_putchar(unsigned char c, int flush)
{
buffer_in[count_in++] = c;
if(flush || (count_in == CDCACM_PACKET_SIZE)) {
/* Refuse to send if USB isn't configured, and
* don't bother if nobody's listening */
if((cdcacm_get_config() != 1) || !cdcacm_get_dtr()) {
count_in = 0;
return;
}
while(usbd_ep_write_packet(usbdev, CDCACM_GDB_ENDPOINT,
(uint8_t *)buffer_in, count_in) <= 0);
count_in = 0;
}
}
void gdb_usb_out_cb(usbd_device *dev, uint8_t ep)
{
(void)ep;
static uint8_t buf[CDCACM_PACKET_SIZE];
usbd_ep_nak_set(dev, CDCACM_GDB_ENDPOINT, 1);
uint32_t count = usbd_ep_read_packet(dev, CDCACM_GDB_ENDPOINT,
(uint8_t *)buf, CDCACM_PACKET_SIZE);
uint32_t idx;
for (idx=0; idx<count; idx++) {
buffer_out[head_out++ % sizeof(buffer_out)] = buf[idx];
}
usbd_ep_nak_set(dev, CDCACM_GDB_ENDPOINT, 0);
}
unsigned char gdb_if_getchar(void)
{
while(tail_out == head_out) {
/* Detach if port closed */
if(!cdcacm_get_dtr())
return 0x04;
while(cdcacm_get_config() != 1);
}
return buffer_out[tail_out++ % sizeof(buffer_out)];
}
unsigned char gdb_if_getchar_to(int timeout)
{
platform_timeout t;
platform_timeout_set(&t, timeout);
if(head_out == tail_out) do {
/* Detach if port closed */
if(!cdcacm_get_dtr())
return 0x04;
while(cdcacm_get_config() != 1);
} while(!platform_timeout_is_expired(&t) && head_out == tail_out);
if(head_out != tail_out)
return gdb_if_getchar();
return -1;
}