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Diffstat (limited to 'src/platforms/tm4c/gdb_if.c')
-rw-r--r--src/platforms/tm4c/gdb_if.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/src/platforms/tm4c/gdb_if.c b/src/platforms/tm4c/gdb_if.c
new file mode 100644
index 0000000..7119638
--- /dev/null
+++ b/src/platforms/tm4c/gdb_if.c
@@ -0,0 +1,102 @@
+/*
+ * 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)
+{
+ timeout_counter = timeout/100;
+
+ if(head_out == tail_out) do {
+ /* Detach if port closed */
+ if(!cdcacm_get_dtr())
+ return 0x04;
+
+ while(cdcacm_get_config() != 1);
+ } while(timeout_counter && head_out == tail_out);
+
+ if(head_out != tail_out)
+ return gdb_if_getchar();
+
+ return -1;
+}
+