2016-06-28 14:35:43 +12:00

133 lines
3.5 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 "cdcacm.h"
#include "gdb_if.h"
static uint32_t count_out;
static uint32_t count_in;
static uint32_t out_ptr;
static uint8_t buffer_out[CDCACM_PACKET_SIZE];
static uint8_t buffer_in[CDCACM_PACKET_SIZE];
#ifdef STM32F4
static volatile uint32_t count_new;
static uint8_t double_buffer_out[CDCACM_PACKET_SIZE];
#endif
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,
buffer_in, count_in) <= 0);
if (flush && (count_in == CDCACM_PACKET_SIZE)) {
/* We need to send an empty packet for some hosts
* to accept this as a complete transfer. */
/* libopencm3 needs a change for us to confirm when
* that transfer is complete, so we just send a packet
* containing a null byte for now.
*/
while (usbd_ep_write_packet(usbdev, CDCACM_GDB_ENDPOINT,
"\0", 1) <= 0);
}
count_in = 0;
}
}
#ifdef STM32F4
void gdb_usb_out_cb(usbd_device *dev, uint8_t ep)
{
(void)ep;
usbd_ep_nak_set(dev, CDCACM_GDB_ENDPOINT, 1);
count_new = usbd_ep_read_packet(dev, CDCACM_GDB_ENDPOINT,
double_buffer_out, CDCACM_PACKET_SIZE);
if(!count_new) {
usbd_ep_nak_set(dev, CDCACM_GDB_ENDPOINT, 0);
}
}
#endif
static void gdb_if_update_buf(void)
{
while (cdcacm_get_config() != 1);
#ifdef STM32F4
asm volatile ("cpsid i; isb");
if (count_new) {
memcpy(buffer_out, double_buffer_out, count_new);
count_out = count_new;
count_new = 0;
out_ptr = 0;
usbd_ep_nak_set(usbdev, CDCACM_GDB_ENDPOINT, 0);
}
asm volatile ("cpsie i; isb");
#else
count_out = usbd_ep_read_packet(usbdev, CDCACM_GDB_ENDPOINT,
buffer_out, CDCACM_PACKET_SIZE);
out_ptr = 0;
#endif
}
unsigned char gdb_if_getchar(void)
{
while (!(out_ptr < count_out)) {
/* Detach if port closed */
if (!cdcacm_get_dtr())
return 0x04;
gdb_if_update_buf();
}
return buffer_out[out_ptr++];
}
unsigned char gdb_if_getchar_to(int timeout)
{
platform_timeout t;
platform_timeout_set(&t, timeout);
if (!(out_ptr < count_out)) do {
/* Detach if port closed */
if (!cdcacm_get_dtr())
return 0x04;
gdb_if_update_buf();
} while (!platform_timeout_is_expired(&t) && !(out_ptr < count_out));
if(out_ptr < count_out)
return gdb_if_getchar();
return -1;
}