add rle encoded loader rom

avr/usbload/rle.c

@@ -0,0 +1,82 @@
+#include <avr/io.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <avr/pgmspace.h>       /* required by usbdrv.h */
+#include <util/delay.h>         /* for _delay_ms() */
+#include <avr/interrupt.h>      /* for sei() */
+
+#include "sram.h"
+#include "debug.h"
+
+#define RUNCHAR 0x90
+
+uint8_t rle_decode(PGM_VOID_P in_addr, int32_t in_len, uint32_t out_addr)
+{
+	uint8_t in_byte, in_repeat, last_byte;
+	uint32_t out_len, out_len_left;
+    printf("RLE decode len=%li addr=0x%08lx\n",in_len,out_addr);
+    
+	out_len_left = out_len;
+    sram_bulk_write_start(out_addr);
+#define INBYTE(b) \
+	do { \
+	         if ( --in_len < 0 ) { \
+			   return 1; \
+		 } \
+         cli();\
+         b = pgm_read_byte((PGM_VOID_P)in_addr++);  \
+         sei();\
+	} while(0)
+
+#define OUTBYTE(b) \
+	do { \
+        sram_bulk_write(b);\
+        sram_bulk_write_next();\
+        out_addr++;\
+	} while(0)
+
+		/*
+		** Handle first byte separately (since we have to get angry
+		** in case of an orphaned RLE code).
+		*/
+	INBYTE(in_byte);
+
+	if (in_byte == RUNCHAR) {
+		INBYTE(in_repeat);
+		if (in_repeat != 0) {
+			/* Note Error, not Incomplete (which is at the end
+			** of the string only). This is a programmer error.
+			*/
+			printf("Orphaned RLE code at start\n");
+			return 1;
+		}
+		OUTBYTE(RUNCHAR);
+	} else {
+		OUTBYTE(in_byte);
+	}
+
+	while( in_len > 0 ) {
+		INBYTE(in_byte);
+        if (in_len%1024==0)
+            printf(".");
+		if (in_byte == RUNCHAR) {
+			INBYTE(in_repeat);
+			if ( in_repeat == 0 ) {
+				/* Just an escaped RUNCHAR value */
+				OUTBYTE(RUNCHAR);
+			} else {
+				/* Pick up value and output a sequence of it */
+                in_byte = last_byte; //;out_data[-1];
+				while ( --in_repeat > 0 )
+					OUTBYTE(in_byte);
+			}
+		} else {
+			/* Normal byte */
+			OUTBYTE(in_byte);
+		}
+        last_byte = in_byte;
+	}
+    sram_bulk_write_end();
+	return 0;
+}
+