feat(esp8266): Add panic function when crash

components/esp8266/source/panic.c

@@ -0,0 +1,133 @@
+// Copyright 2018 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 <string.h>
+
+#include "c_types.h"
+
+#include "esp8266/ets_sys.h"
+#include "esp8266/eagle_soc.h"
+#include "esp8266/uart_register.h"
+
+/*
+ * Todo: panic output UART ID, we may add it to 'kconfig' to select target UART.
+ */
+#define PANIC_UART 0
+
+/*
+ * @brief output a character
+ * 
+ * @param c a character
+ * 
+ * @return none
+ */
+static IRAM_ATTR void panit_putc(char c)
+{
+    while (1) {
+        uint32_t fifo_cnt = READ_PERI_REG(UART_STATUS(PANIC_UART)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
+
+        if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) < 126)
+            break;
+    }
+
+    WRITE_PERI_REG(UART_FIFO(PANIC_UART) , c);
+}
+
+/*
+ * @brief output a left-aligned string
+ * 
+ * @param s string pointer
+ * @param left_aligned left-aligned bytes
+ * 
+ * @return none
+ */
+static IRAM_ATTR void panic_puts(const char *s, int left_aligned)
+{
+    int bytes = left_aligned - strlen(s);
+
+    while (bytes-- > 0)
+        panit_putc(' ');
+
+    while (*s)
+        panit_putc(*s++);
+}
+
+/*
+ * @brief output a hex value string of 32-bites data
+ * 
+ * @param hex 32-bites data
+ * 
+ * @return none
+ */
+static IRAM_ATTR void panic_puthex(int hex)
+{
+    char buf[8];
+    int bytes = 0;
+
+    while (bytes < 8) {
+        char c = (uint32_t)hex % 16;
+
+        if (c < 10)
+            c = c + '0';
+        else
+            c = c - 10 + 'a';
+
+        buf[bytes++] = c;
+        hex >>= 4;
+    }
+
+    while (bytes)
+        panit_putc(buf[--bytes]);
+}
+
+/*
+ * @brief output xtensa register value map when crash
+ * 
+ * @param frame xtensa register value map pointer
+ * 
+ * @return none
+ */
+void IRAM_ATTR panicHandler(void *frame)
+{
+    int *regs = (int *)frame;
+    int x, y;
+    const char *sdesc[] = {
+        "PC",   "PS",   "A0",   "A1",
+        "A2",   "A3",   "A4",   "A5",
+        "A6",   "A7",   "A8",   "A9",
+        "A10",  "A11",  "A12",  "A13",
+        "A14",  "A15",  "SAR",  "EXCCAUSE"
+    };
+
+    /* NMI can interrupt exception. */
+    ETS_INTR_LOCK();
+
+    for (x = 0; x < 20; x += 4) {
+        for (y = 0; y < 4; y++) {
+            panic_puts(sdesc[x + y], 8);
+            panic_puts(": 0x", 0);
+            panic_puthex(regs[x + y + 1]);
+            panic_puts("  ", 0);
+        }
+        panit_putc('\n');
+    }
+
+    /*
+     * Todo: add more option to select here to 'Kconfig':
+     *     1. blocking
+     *     2. restart
+     *     3. GBD break
+     */
+    while (1);
+}