[system/tools]: gdbstub support C3

Closes IDF-1757
Closes IDF-2489

components/esp_gdbstub/esp32c3/gdbstub_esp32c3.c

@@ -0,0 +1,83 @@
+// Copyright 2015-2020 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 "soc/soc.h"
+#include "esp_gdbstub_common.h"
+#include "sdkconfig.h"
+
+#define UART_NUM CONFIG_ESP_CONSOLE_UART_NUM
+
+#define GDBSTUB_MEM_REGION_COUNT 9
+
+typedef struct {
+    intptr_t lower;
+    intptr_t upper;
+} mem_bound_t;
+
+static const mem_bound_t mem_region_table [GDBSTUB_MEM_REGION_COUNT] =
+{
+    {SOC_DROM_LOW, SOC_DROM_HIGH},
+    {SOC_IROM_LOW, SOC_IROM_HIGH},
+    {SOC_IRAM_LOW, SOC_IRAM_HIGH},
+    {SOC_DRAM_LOW, SOC_DRAM_HIGH},
+    {SOC_IROM_MASK_LOW, SOC_IROM_MASK_HIGH},
+    {SOC_DROM_MASK_LOW, SOC_DROM_MASK_HIGH},
+    {SOC_RTC_IRAM_LOW, SOC_RTC_IRAM_HIGH},
+    // RTC DRAM and RTC DATA are identical with RTC IRAM
+    {SOC_PERIPHERAL_LOW, SOC_PERIPHERAL_HIGH},
+    {SOC_DEBUG_LOW, SOC_DEBUG_HIGH},
+};
+
+static inline bool check_inside_valid_region(intptr_t addr)
+{
+    for (size_t i = 0; i < GDBSTUB_MEM_REGION_COUNT; i++) {
+        if (addr >= mem_region_table[i].lower && addr < mem_region_table[i].upper) {
+            return true;
+        }
+    }
+    return false;
+}
+
+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 (!check_inside_valid_region(addr)) {
+        /* see esp_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;
+}