firmware: RLE

src/rle.c

@@ -0,0 +1,66 @@
+
+#include "rle.h"
+#include "fileops.h"
+
+uint8_t rle_file_getc() {
+  static uint16_t rle_filled = 0;
+  static uint8_t data;
+  if(!rle_filled) {
+    data = file_getc();
+    switch(data) {
+      case RLE_RUN:
+        data = file_getc();
+        rle_filled = file_getc()-1;
+        break;
+      case RLE_RUNLONG:
+        data = file_getc();
+        rle_filled = file_getc();
+        rle_filled |= file_getc() << 8;
+        rle_filled--;
+        break;
+      case RLE_ESC:
+        data = file_getc();
+        break;
+    }
+  } else {
+    rle_filled--;
+  }
+  if(file_status || file_res) rle_filled = 0;
+  return data;
+}
+
+void rle_mem_init(const uint8_t* address, uint32_t len) {
+  rle_mem_ptr = address;
+  rle_mem_endptr = address+len;
+  rle_state = 0;
+}
+
+uint8_t rle_mem_getc() {
+  static uint16_t rle_mem_filled = 0;
+  static uint8_t rle_mem_data;
+  if(!rle_mem_filled) {
+    rle_mem_data = *(rle_mem_ptr++);
+    switch(rle_mem_data) {
+      case RLE_RUN:
+        rle_mem_data = *(rle_mem_ptr)++;
+        rle_mem_filled = *(rle_mem_ptr)++ - 1;
+        break;
+      case RLE_RUNLONG:
+        rle_mem_data = *(rle_mem_ptr)++;
+        rle_mem_filled = *(rle_mem_ptr)++;
+        rle_mem_filled |= *(rle_mem_ptr)++ << 8;
+        rle_mem_filled--;
+        break;
+      case RLE_ESC:
+        rle_mem_data = *(rle_mem_ptr)++;
+        break;
+    }
+  } else {
+    rle_mem_filled--;
+  }
+  if(rle_mem_ptr>=rle_mem_endptr){
+    rle_mem_filled = 0;
+    rle_state = 1;
+  }
+  return rle_mem_data;
+}

src/rle.h

@@ -0,0 +1,17 @@
+#ifndef RLE_H
+#define RLE_H
+
+#include <arm/NXP/LPC17xx/LPC17xx.h>
+
+#define RLE_ESC     (0x9b)
+#define RLE_RUN     (0x5b)
+#define RLE_RUNLONG (0x77)
+
+uint8_t rle_file_getc(void);
+uint8_t rle_mem_getc(void);
+void rle_mem_init(const uint8_t *address, uint32_t len);
+const uint8_t *rle_mem_ptr;
+const uint8_t *rle_mem_endptr;
+uint8_t rle_state;
+
+#endif