tools/envcrc: add --binary option to export embedded env

The --binary option to envcrc can be used to export the embedded env as a
binary blob so that it can be manipulated/examined/whatever externally.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

tools/envcrc.c

@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #ifndef __ASSEMBLY__
@@ -77,19 +78,56 @@ extern unsigned char environment;
 int main (int argc, char **argv)
 {
 #ifdef	ENV_IS_EMBEDDED
+	unsigned char pad = 0x00;
 	uint32_t crc;
 	unsigned char *envptr = &environment,
 		*dataptr = envptr + ENV_HEADER_SIZE;
 	unsigned int datasize = ENV_SIZE;
+	unsigned int eoe;
+
+	if (argv[1] && !strncmp(argv[1], "--binary", 8)) {
+		int ipad = 0xff;
+		if (argv[1][8] == '=')
+			sscanf(argv[1] + 9, "%i", &ipad);
+		pad = ipad;
+	}
+
+	if (pad) {
+		/* find the end of env */
+		for (eoe = 0; eoe < datasize - 1; ++eoe)
+			if (!dataptr[eoe] && !dataptr[eoe+1]) {
+				eoe += 2;
+				break;
+			}
+		if (eoe < datasize - 1)
+			memset(dataptr + eoe, pad, datasize - eoe);
+	}
 
 	crc = crc32 (0, dataptr, datasize);
 
 	/* Check if verbose mode is activated passing a parameter to the program */
 	if (argc > 1) {
-		printf ("CRC32 from offset %08X to %08X of environment = %08X\n",
-			(unsigned int) (dataptr - envptr),
-			(unsigned int) (dataptr - envptr) + datasize,
-			crc);
+		if (!strncmp(argv[1], "--binary", 8)) {
+			int le = (argc > 2 ? !strcmp(argv[2], "le") : 1);
+			size_t i, start, end, step;
+			if (le) {
+				start = 0;
+				end = ENV_HEADER_SIZE;
+				step = 1;
+			} else {
+				start = ENV_HEADER_SIZE - 1;
+				end = -1;
+				step = -1;
+			}
+			for (i = start; i != end; i += step)
+				printf("%c", (crc & (0xFF << (i * 8))) >> (i * 8));
+			fwrite(dataptr, 1, datasize, stdout);
+		} else {
+			printf("CRC32 from offset %08X to %08X of environment = %08X\n",
+				(unsigned int) (dataptr - envptr),
+				(unsigned int) (dataptr - envptr) + datasize,
+				crc);
+		}
 	} else {
 		printf ("0x%08X\n", crc);
 	}