add files from nrf52832 bootloader project

nRF5_SDK_11.0.0_89a8197/components/libraries/slip/slip.c

@@ -0,0 +1,112 @@
+/* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.
+ *
+ * The information contained herein is property of Nordic Semiconductor ASA.
+ * Terms and conditions of usage are described in detail in NORDIC
+ * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
+ *
+ * Licensees are granted free, non-transferable use of the information. NO
+ * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
+ * the file.
+ *
+ */
+ 
+#include "slip.h"
+#include "nrf_error.h"
+
+#define SLIP_END             0300    /* indicates end of packet */
+#define SLIP_ESC             0333    /* indicates byte stuffing */
+#define SLIP_ESC_END         0334    /* ESC ESC_END means END data byte */
+#define SLIP_ESC_ESC         0335    /* ESC ESC_ESC means ESC data byte */
+
+
+uint32_t slip_encode(uint8_t * p_output,  uint8_t * p_input, uint32_t input_length, uint32_t output_buffer_length)
+{
+    uint32_t input_index;
+    uint32_t output_index;
+    
+    for (input_index = 0, output_index = 0; input_index < input_length && output_index < output_buffer_length; input_index++)
+    {
+        switch (p_input[input_index])
+        {
+            case SLIP_END:
+                p_output[output_index++] = SLIP_END;
+                p_output[output_index++] = SLIP_ESC_END;
+                break;
+            
+            case SLIP_ESC:
+                p_output[output_index++] = SLIP_ESC;
+                p_output[output_index++] = SLIP_ESC_ESC;
+                break;
+                
+            default:
+                p_output[output_index++] = p_input[input_index];
+        }
+    }
+    p_output[output_index++] = (uint8_t)SLIP_END;
+    p_output[output_index++] = (uint8_t)SLIP_END; // clarify that the packet has ended.
+    
+    return output_index;
+}
+
+
+uint32_t slip_decoding_add_char(uint8_t c, buffer_t * p_buf, slip_state_t * current_state)
+{   
+    switch (*current_state)
+    {
+        case SLIP_DECODING:
+            if (c == SLIP_END)
+            {
+                *current_state = SLIP_END_RECEIVED;
+            }
+            else if (c == SLIP_ESC)
+            {
+                *current_state = SLIP_END_RECEIVED;
+            }
+            else 
+            {
+                p_buf->p_buffer[p_buf->current_index++] = c;
+                p_buf->current_length++;
+            }
+            break;
+        
+        case SLIP_ESC_RECEIVED:
+            if (c == SLIP_ESC_ESC)
+            {
+                p_buf->p_buffer[p_buf->current_index++] = SLIP_ESC; 
+                p_buf->current_length++;  
+                *current_state = SLIP_DECODING;                
+            }
+            else
+            {
+                // violation of protocol
+                *current_state = SLIP_CLEARING_INVALID_PACKET;
+                return NRF_ERROR_INVALID_DATA;
+            }
+            break;
+            
+        case SLIP_END_RECEIVED:
+            if (c == SLIP_ESC_END)
+            {
+                p_buf->p_buffer[p_buf->current_index++] = SLIP_END;
+                p_buf->current_length++;
+                *current_state = SLIP_DECODING;
+            }
+            else 
+            {
+                // packet is finished
+                *current_state = SLIP_DECODING;                 
+                return NRF_SUCCESS;
+            }
+            break;       
+        
+        case SLIP_CLEARING_INVALID_PACKET:
+            if (c == SLIP_END)
+            {
+                *current_state = SLIP_DECODING;        
+                p_buf->current_index = 0;
+                p_buf->current_length = 0;
+            }
+            break;
+    } 
+    return NRF_ERROR_BUSY;
+}

nRF5_SDK_11.0.0_89a8197/components/libraries/slip/slip.h

@@ -0,0 +1,66 @@
+/* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.
+ *
+ * The information contained herein is property of Nordic Semiconductor ASA.
+ * Terms and conditions of usage are described in detail in NORDIC
+ * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
+ *
+ * Licensees are granted free, non-transferable use of the information. NO
+ * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
+ * the file.
+ *
+ */
+ 
+#ifndef SLIP_H__
+#define SLIP_H__
+
+#include <stdint.h>
+#include "app_fifo.h"
+
+/** @file
+ *
+ * @defgroup slip SLIP encoding decoding
+ * @{
+ * @ingroup app_common
+ *
+ * @brief  This module encodes and decodes slip packages (RFC1055).
+ *
+ * @details The standard is described in https://tools.ietf.org/html/rfc1055
+ */
+  
+typedef enum {
+    SLIP_DECODING,
+    SLIP_END_RECEIVED,
+    SLIP_ESC_RECEIVED,
+    SLIP_CLEARING_INVALID_PACKET,
+} slip_state_t;
+
+typedef struct {
+    uint8_t * p_buffer;
+    uint32_t current_index;
+    uint32_t current_length;
+    uint32_t len;
+} buffer_t; 
+  
+/**@brief Encodes a slip packet.
+ * 
+ * @details Note that the encoded output data will be longer than the input data. 
+ *
+ * @retval The length of the encoded packet. If it is smaller than the input length, an error has occurred. 
+ */
+uint32_t slip_encode(uint8_t * p_output,  uint8_t * p_input, uint32_t input_length, uint32_t output_buffer_length);
+
+/**@brief Decodes a slip packet.
+ * 
+ * @details When decoding a slip packet, a state must be preserved. Initial state must be set to SLIP_DECODING.
+ *
+ * @retval NRF_SUCCESS when a packet is parsed. The length of the packet can be read out from p_buf->current_index
+ * @retval NRF_ERROR_BUSY when packet is not finished parsing
+ * @retval NRF_ERROR_INVALID_DATA when packet is encoded wrong. 
+           This moves the decoding to SLIP_CLEARING_INVALID_PACKET, and will stay in this state until SLIP_END is encountered.
+ */
+uint32_t slip_decoding_add_char(uint8_t c, buffer_t * p_buf, slip_state_t * current_state);
+
+
+#endif // SLIP_H__
+
+/** @} */