esp32s2beta: add gdbstub support

components/esp_gdbstub/esp32s2beta/gdbstub_esp32s2beta.c

@@ -0,0 +1,51 @@
+// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "soc/uart_periph.h"
+#include "soc/gpio_periph.h"
+#include "esp_gdbstub_common.h"
+#include "sdkconfig.h"
+
+#define UART_NUM CONFIG_ESP_CONSOLE_UART_NUM
+
+void esp_gdbstub_target_init()
+{
+}
+
+int esp_gdbstub_getchar()
+{
+    while (REG_GET_FIELD(UART_STATUS_REG(UART_NUM), UART_RXFIFO_CNT) == 0) {
+        ;
+    }
+    return REG_READ(UART_FIFO_AHB_REG(UART_NUM));
+}
+
+void esp_gdbstub_putchar(int c)
+{
+    while (REG_GET_FIELD(UART_STATUS_REG(UART_NUM), UART_TXFIFO_CNT) >= 126) {
+        ;
+    }
+    REG_WRITE(UART_FIFO_AHB_REG(UART_NUM), c);
+}
+
+int esp_gdbstub_readmem(intptr_t addr)
+{
+    if (addr < 0x20000000 || addr >= 0x80000000) {
+        /* see cpu_configure_region_protection */
+        return -1;
+    }
+    uint32_t val_aligned = *(uint32_t *)(addr & (~3));
+    uint32_t shift = (addr & 3) * 8;
+    return (val_aligned >> shift) & 0xff;
+}